Ready to Push it Off a Cliff!

[GhostDakota]

This is for my 98, my "daily driver" that I can't drive anymore! I was driving in to work 1-2 months ago and I noticed some hesitation in 6th gear at 65 MPH. Wasn't a big deal I thought. Then, I noticed it in lower gears/RPMs, and now while accelerating in every gear. It's like a full auto AK-47, for example, in terms of rate (not loudness). It does not happen at idle while revving unless I turn the car on and it starts doing it right off the bat.

My SES light has been on for months now. It's telling me the driver side o2 reading is off. On my drive to/from the Hamptons just prior to all this I hit 2389048923480234 bumps, pot holes, etc., mainly on the Belt Parkway & Staten Island Expressway. Is it possible it rattled my cat apart and is now clogged up?

I don't think it's bad gas, but who knows. I've always run Sunoco 93 octane gas. Over the weekend I was in the Hamptons and had to fill with Hess gas. I ran through that tank after a couple days, and filled up with Sunoco.

I have 109,XXX miles and do not think that the prior owner changed the wires. The plugs are half and half. I just changed the wires to Vengeance Racing:
http://pafirefighter11.smugmug.com/photos/i-bCMPT8c/0/L/i-bCMPT8c-L.jpg

Also running new TR55 NGK plugs gapped to .055. The gap of the old plugs was at .085!

These are the plugs, set up in cylinder order. Top plugs are the front of the vehicle:
http://pafirefighter11.smugmug.com/photos/i-kLNnwFP/1/L/i-kLNnwFP-L.jpg

Codes:
P0420 - original code I've had for some time
P0300 - Random misfire detected
P0140 - o2 circuit blah blah (from when I disconnected the driver side downstream o2 sensor)

I got the CRC MAF cleaner. Cleaned it during my lunch break. Still sputtering - mainly under WOT, but it's still there at other points on and off as well. I swapped the MAF from my '01 and still the same issues.

Any recommendations are appreciated. I just want to drive this car and ENJOY it again :cry:

[V]

have you checked the coils? My SS had weird sputtering misfiring. I had MSD coils with less than 5k miles. I swapped in a set of used stock ones and it ran great after that.

[GhostDakota]

have you checked the coils? My SS had weird sputtering misfiring. I had MSD coils with less than 5k miles. I swapped in a set of used stock ones and it ran great after that.

I haven't. What's the best way to test the coils aside from licking my finger and touching it? lol..

[BonzoHansen]

So it has new wires, new plugs, no change? No issue at idle even giveng it gas, so it needs load to create the problem? how many miels on the new plugs? you might be able to look at the plug and see if a cyl is laying down on you

smack the cats with your hand and listen for rattles. too bad you don; thav ethose back 02s in, they'd tell you.

when is the last time the fuel flter was changed?

[GhostDakota]

So it has new wires, new plugs, no change? No issue at idle even giveng it gas, so it needs load to create the problem? how many miels on the new plugs? you might be able to look at the plug and see if a cyl is laying down on you

smack the cats with your hand and listen for rattles. too bad you don; thav ethose back 02s in, they'd tell you.

when is the last time the fuel flter was changed?

I just installed the new plugs and wires on Sunday. I drove 25 miles home on them and have not driven the car since. The odd thing is, load is not required. Sometimes I can do a cold start up and it is fine, other times it's instantly sputtering - but not blinking the SES.

All 4 o2s are in place (Pass/driver, up and downstream). The only one currently disconnected is the pass. upstream o2 as it ran best with that one unplugged.

I doubt the fuel filter has been changed. Is it on the frame rail like most vehicles?

[WildBillyT]

Any codes for your front O2s?

[BonzoHansen]

I just installed the new plugs and wires on Sunday. I drove 25 miles home on them and have not driven the car since. The odd thing is, load is not required. Sometimes I can do a cold start up and it is fine, other times it's instantly sputtering - but not blinking the SES.

All 4 o2s are in place (Pass/driver, up and downstream). The only one currently disconnected is the pass. upstream o2 as it ran best with that one unplugged.

I doubt the fuel filter has been changed. Is it on the frame rail like most vehicles?

pull the plugs look for one that is different colors than the others. that might pinpoint a bad coil/plug/wire

wait, you have a front O2 unplugged???????? and that made it run better? Is that right?

Yes, filter is low & in the back - RH side IIRC. Quick release on one side, flare on the other.

[GhostDakota]

Any codes for your front O2s?

Codes:
P0420 - Catalyst Efficieny below threshold Bank 1
P0300 - Random misfire detected
P0140 - o2 Sensor No Activity Detected (from when I disconnected the one o2 sensor)



pull the plugs look for one that is different colors than the others. that might pinpoint a bad coil/plug/wire

wait, you have a front O2 unplugged???????? and that made it run better? Is that right?

Yes, filter is low & in the back - RH side IIRC. Quick release on one side, flare on the other.


Even with only 25 miles? That was such a PITA and I never want to do that again lol. My damn hands are too big.

Yes, the front o2 is unplugged and it ran a lot better with it like that. On my Jeeps at least, if the front o2 is not reading/unplugged, the computer will run a pre-programmed setting.

I'll check the filter, thanks!

[BonzoHansen]

you need to fix the issue related to the front O2 sensor. those are important. unplugging a sensor is never the right answer. at least plug it back in, clear the codes. I'd change that filter first, if for S&Gs.

yes, 25 crappy miles may be enough to show a dirty plug.

[WildBillyT]

Codes:
P0420 - Catalyst Efficieny below threshold Bank 1
P0300 - Random misfire detected
P0140 - o2 Sensor No Activity Detected (from when I disconnected the one o2 sensor)






Even with only 25 miles? That was such a PITA and I never want to do that again lol. My damn hands are too big.

Yes, the front o2 is unplugged and it ran a lot better with it like that. On my Jeeps at least, if the front o2 is not reading/unplugged, the computer will run a pre-programmed setting.

I'll check the filter, thanks!

Disconnecting the front O2 will put you into open loop, which kind of isolates where the problem may be.

Have you changed anything since it was running well?

[GhostDakota]

you need to fix the issue related to the front O2 sensor. those are important. unplugging a sensor is never the right answer. at least plug it back in, clear the codes. I'd change that filter first, if for S&Gs.

yes, 25 crappy miles may be enough to show a dirty plug.

Alright, I'll plug it back in - I don't have a lift or jack at home (I live in a condo with a gated parking lot where we can't do work to our vehicles). I've been bugging my buddy to use his shop and lift, but he's a good 1.5 hours away so it's a bitch of a drive with it running like this.

I'll look for a fuel filter, thanks.



Disconnecting the front O2 will put you into open loop, which kind of isolates where the problem may be.

Have you changed anything since it was running well?

Exactly - I meant loop lol. Thanks.

Nothing was changed to the vehicle between when it was running well (with the SES light on) and when it stopped running well.

[grazi]

MIne did somethign similiar when my cat was plugged. I used an infrared thermometer to compare the temp difference between the front and back of the cat. Mine was about 400 degrees difference. I think I remember reading that there should only be a 50 degree difference. Someone can correct em if I'm wrong. But mine wasnt throwing any codes.
I gutted it and it's ran perfect since.

[GhostDakota]

MIne did somethign similiar when my cat was plugged. I used an infrared thermometer to compare the temp difference between the front and back of the cat. Mine was about 400 degrees difference. I think I remember reading that there should only be a 50 degree difference. Someone can correct em if I'm wrong. But mine wasnt throwing any codes.
I gutted it and it's ran perfect since.

****, I knew I was forgetting something! My g/f is a chef and has an infrared thermometer. I need to pick up a 9V battery and test that out. Did you let it fully warm up? I have a 160* t-stat so the motor doesn't get "too hot"..., but I'm sure the exhaust is still quite hot.

[grazi]

Yeah, I let mine warm up. The 160 will be water temp but that exhaust is going to be real hot.I believe my header side got around 800 and the muffler side stayed around 400.

[sweetbmxrider]

You have a cat code, do you have cats on the car? I would bang on them. If you hear any rattling, its the honeycomb that broke apart and is now clogging your exhaust system. This will certainly cause running issues especially the way you are describing. Hell, you could just pull the front o2's, starting with the driver side, and see if it runs better. This will tell you if you have a clogged cat.

[coolmanvette75]

P0420 is the bank 1 cat. I get these codes at work all the time and 99% of the time the cat is clogged

[GhostDakota]

o2's are in. Cats seemed okay by hitting on them. No broken honeycomb noise that I could ascertain.

Drove to my buddies. He is a mechanic for UPS. It was approx. a 35 minute drive. Car was fine for 3 minutes then went to misfire. It mainly misfires above 25 MPH, typically in the higher gears and higher RPMs. On the highway it's almost a constant misfire (CEL blinking) until I drop down below 25 MPH and then eventually it stops blinking, though I still feel the misfire.

Checked the passenger side cat - it's okay. Didn't get a chance to check driver side cat. We did check both cats with my g/f's infrared thermometer. Driver side was 475, passenger side 375. Between the front/back of the cats it was only approx. 40-60* max. Here's where things get odd though...

We figured we would test the injectors, coil packs, etc. While the car was running we pulled one injector (the wiring obviously) at a time. Each injector, when unplugged, caused the motor to drop and run worse than it already was. That was, until we got to cylinder 5. When we pulled the plug on cylinder 5, nothing happened. We swapped coil packs quick to see if it was related to the coil. The problem did not move.

We swapped the #5 injector to a Ford injector that was the same clip/setup, just to see what happened. Started up the car and my CEL turned off. (It's showing a P0420 for the o2, and a random cylinder misfire btw). The problem got worse. We put the stock injector back in to #5. CEL came back on.

Ohmed out the injectors. All were around 13.1, though on cylinder 5 we had a a reading of 14.2 and also 13.2.

I drove to Pep Boys just to get some Sea Foam for S&G's. Left my buddies, drove the 5 minutes there. Car drove like ****. Went inside, no Sea Foam, came out. Started the car and it drove perfect for about 5 minutes. Then back into crap. 10 more minutes and I was at Advance Auto. Went in, got Sea Foam, came back outside. Car drove great for 5 more minutes, then back to crap again.

Bad injector? Something internal? Something else?? I just sold my Jeep and it's too cold for the bike so I NEED to get this car up and running as it's my DD now 'til I pick up a new Jeep. Thanks...

[JL8Jeff]

Check things like the AIR check valves to make sure they are working properly. I've seen a few of the AIR check valves stop working and it allows air into the exhaust that the computer isn't expecting and will throw off the O2 readings and make the computer make bad adjustments. Also, did the car really have 2 different types of plugs in it? The AC's look like platinum or irridium, but the NGK's look like regular plugs. Also check the EVAP lines and valves to make sure it's not sucking additional air constantly from the tank. It almost sounds like you have a vacuum/air leak on the driver's side throwing off the O2 readings and the cat is running hotter as well.

[GhostDakota]

Check things like the AIR check valves to make sure they are working properly. I've seen a few of the AIR check valves stop working and it allows air into the exhaust that the computer isn't expecting and will throw off the O2 readings and make the computer make bad adjustments. Also, did the car really have 2 different types of plugs in it? The AC's look like platinum or irridium, but the NGK's look like regular plugs. Also check the EVAP lines and valves to make sure it's not sucking additional air constantly from the tank. It almost sounds like you have a vacuum/air leak on the driver's side throwing off the O2 readings and the cat is running hotter as well.

It's funny you mention a vacuum leak. Check this out:

I was fixing my driver side headlight motor gear and noticed these tubes just chilling (Pardon the cell phone shot):
http://pafirefighter11.smugmug.com/Automotive/1998-Pontiac-Trans-Am/i-2CLjVVs/0/XL/IMAG0461-XL.jpg

One smaller tube attaches to the large tube and goes back towards the wheel well and is attached. Another smaller tube is also attached to the large tube (on the side) which you can see and goes to nothing at the moment.

I taped up the end so it's not open to air at the moment.

[Mike]

What about the open hole in your exhaust manifold in your very first picture

[GhostDakota]

What about the open hole in your exhaust manifold in your very first picture

That was only to access the spark plugs/wires.

Here's a quick cell phone video of some revs and idle - I can take other videos as needed and use the GoPro. I just unplugged the AIR fuse and relay (Since my system is missing due to the prior owner) then started it up like this:

http://www.youtube.com/watch?v=_n_8yLhQNtU

[V]

can you find/identify that open piping in this pic?

http://parts.nalleygmc.com/images/parts/gm/fullsize/970822MF03-109.JPG

[GhostDakota]

It looks like 18 & 11. I'm pretty sure the prior owner attempted to remove the AIR system? If that's the case, should I have unplugged the AIR pump relay and fuse, or just the fuse?

[V]

the AIR system should be turned off in the PCM if it has been removed, I'm not sure if a fuse will properly disconnect it

[sweetbmxrider]

Can you get a noid light to make sure the injector is being pulsed and you don't have a broken wire or something?

[GhostDakota]

the AIR system should be turned off in the PCM if it has been removed, I'm not sure if a fuse will properly disconnect it

Hose 18 seems to be the one that is under there and runs to nowhere. However, I checked and everything else for the AIR is there.

Crappy photos again (I don't have a lift, ramps, etc. at the moment):

http://pafirefighter11.smugmug.com/photos/i-GQsLGbr/1/XL/i-GQsLGbr-XL.jpg

http://pafirefighter11.smugmug.com/photos/i-T9S763F/1/XL/i-T9S763F-XL.jpg

http://pafirefighter11.smugmug.com/photos/i-xbHpBp9/1/XL/i-xbHpBp9-XL.jpg



Can you get a noid light to make sure the injector is being pulsed and you don't have a broken wire or something?

Never used a noid light. When my mechanic buddy listed to the injectors he said the #5 injector sounded different, but was making noise. I'm just going to pick up a used injector first to see if that does anything. If that's the case, great! If not, I'll get the noid kit.

[sweetbmxrider]

Its just a little light that fits into the injector connector. The light blinks as power/ground is sent through it. If you are hearing noise though, I would assume it is alright but you know what they say. Also, I thought you said you swapped the injector around and the problem stayed, not followed the injector, which makes me think its not the entire issue. I have been wrong before!

[GhostDakota]

Its just a little light that fits into the injector connector. The light blinks as power/ground is sent through it. If you are hearing noise though, I would assume it is alright but you know what they say. Also, I thought you said you swapped the injector around and the problem stayed, not followed the injector, which makes me think its not the entire issue. I have been wrong before!

Gotcha! We didn't swap the OE injectors around, we just used a Ford Injector we had laying around. Probably should've swapped the one injector to another cylinder, but it was freezing and we ran out of light. My buddy has a bunch of injectors from his f-body's laying around. I'm going to grab one and see if that does anything.

[sweetbmxrider]

Oh ok, I thought you swapped it around and then swapped in the ford one. Must have been the coils I was thinking about.

[JL8Jeff]

It's funny you mention a vacuum leak. Check this out:

I was fixing my driver side headlight motor gear and noticed these tubes just chilling (Pardon the cell phone shot):
http://pafirefighter11.smugmug.com/Automotive/1998-Pontiac-Trans-Am/i-2CLjVVs/0/XL/IMAG0461-XL.jpg

One smaller tube attaches to the large tube and goes back towards the wheel well and is attached. Another smaller tube is also attached to the large tube (on the side) which you can see and goes to nothing at the moment.

I taped up the end so it's not open to air at the moment.

That might just be part of the stock air intake resonator which looks like it was cut off. I can't remember for sure but I think the LS1 cars use the stock air filter box to filter air for the AIR setup. You might need to leave that open so the the AIR pump has an air source if that's what it is. Check your vacuum lines and double check the AIR check valves to make sure the air can only go one way.

It looks like #21 in your photo and that looks like it's just a vent hose.

[GhostDakota]

No noid testing yet. Found more out today though...

#5 AND #7 injectors, when unplugged, have no bearing on how the car runs. 1, 2, 3, 4, 6, 8 all drop the idle immediately when unplugged, and it goes back up once plugged back in.

Replaced #5 injector with a confirmed working injector out of my buddies g/f's '98 Camaro SS that was wrecked. Same injector part #. Car ran great for about 1-2 minutes after startup, then went right back to ****.

My LS buddies (Two brothers who currently and have owned way too many f-body vehicles over the years) took a look at it. They mentioned wiring harness issues, but were perplexed. Said with the way it runs great sometimes at startup, but then other times doesn't, is very odd... Damn this car lol.

[JL8Jeff]

There might be an injector wire harness TSB on these cars so search around for that. Also look for a possible loose ground somewhere on the engine.

[The_Bishop]

PCM shot, maybe?

[GhostDakota]

Jeff, I'll check for the grounds next chance I get. I had to drive my TA in the snow today, driving like ****, 'cause I sold my Jeep and won't get my new one 'til Friday. FML. Is there a site to look up TSB's or would I need to call a dealer?

Bishop, I've been reading about people who think they have a bad PCM. It seems like I have some symptoms, but not all.

Odd thing I noticed yesterday is that my 3rd brake light is illuminated when I have my lights on, just like my rear running lights. It gets brighter when I hit my brake likes as would a rear running light. Also having the alarm issue where it goes off by itself after a car wash or in the rain - for no reason. My low coolant light is on but too, but haven't had time to check the level. Some other intermittent electrical things as well.

EDIT: My '01 PCM wouldn't work in my '98 right?

[V]

EDIT: My '01 PCM wouldn't work in my '98 right?

nope

[GhostDakota]

Figured. Out of curiosity... I took the descreened MAF off my '01 and it's now on my '98. Would that be causing issues or are they the same 98-02?

[WildBillyT]

Figured. Out of curiosity... I took the descreened MAF off my '01 and it's now on my '98. Would that be causing issues or are they the same 98-02?

A descreened MAF can cause a world of hurt. Speaking from firsthand experience. Try that and post up.

[GhostDakota]

A descreened MAF can cause a world of hurt. Speaking from firsthand experience. Try that and post up.

Okay, great. Will do that when I have free time, maybe tomorrow during lunch, and report back.

[The_Bishop]

Speaking from tuning experience, don't descreen MAF sensors. Does far more harm than good.

[GhostDakota]

Speaking from tuning experience, don't descreen MAF sensors. Does far more harm than good.

I didn't - the ex did it lol. Then I bought her car as my project.

[GhostDakota]

Odd thing - I disconnected the MAF last night, just for S&G's, then started it up. It ran like pure crap (worse than before). I plugged it back in and drove home. On the highway, in 5th gear, the car seemed to be running on 7, possibly even 7.5 cylinders lol, versus the 6 it was normally running on. Even on the back roads off the highway just before my house it ran better. The SES light wasn't even flashing as it used to do!

Then, this morning I started it up and it's back to 6 cylinders. SES flashes at speeds mainly above 35, as it did before.

I will be swapping MAF's back to my stock one today.

[BigAls87Z28]

Check Engine light is still on? If so, what are the codes?

[GhostDakota]

I reset the ECU by turning the key on, removing the two ECU fuses, turning the key off after 10 minutes, then replacing the fuses. SES light turned off. Car started up great. Drove for approx. 1 minute, then it went back to driving like ****.

SES light came on again after approx. 3 minutes, then blinking shortly after.

Codes listed on post #1:

P0420 - Original code I've had for over a year (Catalyst efficiency below threshold ...)
P0300 - Random misfire detected
P0140 - o2 circuit blah blah (from when I disconnected the driver side downstream o2 sensor)

Have not re-checked to see if there are any new codes.

[edpontiac91]

ANY thoughts about just taking this to a Chevrolet Dealer/ or a High Performance shop with a good reputation? It seems like you'll make yourself crazy before you find the problem.

[rickyd13]

Maybe that cat is shot and making back pressure and the engine and messing with your o2

[GhostDakota]

I think my next steps are:

-Driver side upstream o2
-Driver side cat

If it still sucks, I may consider taking it to Josh at JS Speed in Hulmeville, PA or to Andrew at CSP in West Chester, PA.

[BonzoHansen]

you should make a complete list of all the issues & alterations

[BigAls87Z28]

P0420 is not an O2 sensor code. Lots of people think it is, but it has to be the MOST common code I see. Usually it's related to an exhaust leak, and judging by all that missing AIR stuff, I would venture a guess as to that being the problem?

P0140 code is more specific, but could still be the whole missing AIR stuff.

As for misfire, what else have you checked? Wires? Coils?

[WildBillyT]

P0420 is not an O2 sensor code. Lots of people think it is, but it has to be the MOST common code I see. Usually it's related to an exhaust leak, and judging by all that missing AIR stuff, I would venture a guess as to that being the problem?

P0140 code is more specific, but could still be the whole missing AIR stuff.
As for misfire, what else have you checked? Wires? Coils?

Al, I was thinking about this in one of the earlier pics. Looks like the AIR tube is open to atmospheric (not capped). I am unsure if you can run them like this.

[BigAls87Z28]

Okay, went back and reread some of the stuff. You pulled the AIR stuff apart to get the plugs, so that makes sense as to why your are missing it in that picture. I hope that when you put it all back together that you used some sort of hi-temp gasket material so that you don't have leaks that could cause other problems on top of the problems you already have.

So you replaced the plugs and then all these problems came up, or did you have a problem then replace the plugs?
Have you checked the coil?
If he's misfiring like an "AK47", that will cause the O2 codes to trip. O2's are probably covered in a lot of fuel, and they looooove that.

Check the coils, might have a problem there. Swap some of them around, see if that changes the rate or the pitch of the misfires. You might be looking at one, or more, new coils.

[GhostDakota]

Okay, went back and reread some of the stuff. You pulled the AIR stuff apart to get the plugs, so that makes sense as to why your are missing it in that picture. I hope that when you put it all back together that you used some sort of hi-temp gasket material so that you don't have leaks that could cause other problems on top of the problems you already have.

So you replaced the plugs and then all these problems came up, or did you have a problem then replace the plugs?
Have you checked the coil?
If he's misfiring like an "AK47", that will cause the O2 codes to trip. O2's are probably covered in a lot of fuel, and they looooove that.

Check the coils, might have a problem there. Swap some of them around, see if that changes the rate or the pitch of the misfires. You might be looking at one, or more, new coils.

The P0420 code started over a year ago (August 2011 or so). No negative/adverse driving issues were occurring at the time.

The misfire started when I returned from the Hamptons several months ago (July 2012?). No high RPM driving to/from the Hamptons, just highway through some ****** parkways (Belt, LI, etc.).

Because of the misfire I:

-Replaced the plugs
-Replaced the wires
-Swapped coils around (Problem stayed on #5 & #7)
-Removed #5 injector, replaced with a known working injector
-Checked cats using infrared thermometer & tap test:
----Driver side 450*/400*, no rattling
----Pass. side 350*/300*, no rattling

GOtta run, post more later.

[JL8Jeff]

It sounds like you need to check the injectors or injector harness to get that #5 injector firing properly before worrying about the other codes. I saw there is a TSB for electrical harness for 1999 Firebirds TSB 03-06-04-012A to inspect the harness but it doesn't give any specifics. Maybe a good scan tool will show if the #5 injector is truly getting the signal to the injector.

[BonzoHansen]

It sounds like you need to check the injectors or injector harness to get that #5 injector firing properly before worrying about the other codes. I saw there is a TSB for electrical harness for 1999 Firebirds TSB 03-06-04-012A to inspect the harness but it doesn't give any specifics. Maybe a good scan tool will show if the #5 injector is truly getting the signal to the injector.

or a simple noid light

[The_Bishop]

That wouldn't cause misfiring.

[GhostDakota]

The 160* t-stat has been in the car for over 2 years. I don't see that causing a problem.

I just got a noid light on it today. Both #5 and #7 injector connectors are pulsing properly.

[GhostDakota]

A guy who is local to me on Yellow Bullet is going to hook his scanner up to it and see what's going on. He has one of those DRB style tools (Really expensive diagnostic ones). Shooting for Saturday.

[GhostDakota]

Okay, so my buddy (He has been building engines for decades) looked at it yesterday. Hooked up one of those super expensive Snapon scanners. The o2's are reading fine, so it seems the o2's and cats are good. He saw that cyl's #5 and #7 were misfiring. At times #8 would hop on the misfire bandwagon, and #6 seemed to be having minor issues as well at times. He swapped out all the driver side coils to some from his LQ4, the problem remained. Injectors seem fine.

At this point he thinks it's either the ECU or wiring in the harness, possibly even a bad ground somewhere. Some random electrical issues pop up such as the turn signals blinking real fast, then real slow, then fast and slow when I activate them. Also my third brake light will light up like a regular tail light: On while the parking lights are on, then when I hit the brake it gets brighter. When revving the Check Gauges light 1/4 illuminates sometimes, which is odd. A few other odd things occur from time to time as well.

At this point I need to find a '98 Camaro SS or Trans Am computer and swap that in there. See if the problem is resolved. Anyone have one to loan out?

[Mike]

99 won't work?

[GhostDakota]

Nope, it seems '98 is unique. Of course. My buddy just told me he has a few spares, including a '98, so I'm heading over there today to grab it.

[GhostDakota]

Borrowed an ECU from my buddy. He had several from his past vehicles. He gave me one out of a '98 Camaro SS. Swapped it in and still runs like crap. Very strong odor of raw fuel.

When I pulled the old ECU I did notice some white corrosion and residue. It was on both the lower wiring harness connector as well as the ECU connector itself. Hard to see here but it's the ECU on the left, very bottom, the flash made it look brighter:
http://pafirefighter11.smugmug.com/photos/i-K2nm3KG/1/XL/i-K2nm3KG-XL.jpg

[JL8Jeff]

Sound like an electrical issue. Try and check all the grounds then start looking at the wiring to see if anything is rubbing through somewhere causing it to energize the whole frame/body. Also check the alternator/voltage regulator to make sure it's not overcharging.

[GhostDakota]

Sound like an electrical issue. Try and check all the grounds then start looking at the wiring to see if anything is rubbing through somewhere causing it to energize the whole frame/body. Also check the alternator/voltage regulator to make sure it's not overcharging.

It's charging pretty high (not in the red though) 'cause I did the high output Escalade alternator swap. The car blew 2 alternators before I did this. There is a HUGE post over on "Tech" about it.

[Tru2Chevy]

After re-reading this entire thread I think your next step is to set aside some time and really check out the entire harness. I think you mentioned an aftermarket alarm? If so, locate that and all associated wiring and check it over very well. Could be that one of more of the connections from the aftermarket alarm to the factory harness are failing and causing shorts or other odd behavior.

It sounds like there are too many different issues going on (long term code, misfire, brake light issue, turn signal issues) to be able to point to one specific cause (other than a harness issue).

- Justin

[GhostDakota]

Thanks, Justin. Factory alarm that was always on the fritz, as seems the issue with most factory F-body alarms.

All the electrical things made me really believe that it was an ECU. I'm pissed it wasn't 'cause I had a good deal on this ECU if it did fix the problem.

Speaking of ECU's, does anyone know how long it takes for a replacement ECU to idle well on a new car? i.e. does it have to go through a couple warm up cycles, or just one idle and it'll learn?

[sweetbmxrider]

Pending the conditions, it can take a few start ups and drives for it to learn all necessary parameters.

[GhostDakota]

Alright, I'll give it a few more starts and drive it too. I didn't want to move it since it was idling so badly.

[GhostDakota]

First I'm going to see if I can get the new computer to learn everything and work. If not, on to the grounds.

2 interesting things. First, I just noticided this on the ECU I pulled from my car:
http://ls1tech.com/forums/attachment.php?attachmentid=385950&dateline=1357256003

Second here's the crap that's all over both the ECU and the harness side:
http://ls1tech.com/forums/attachment.php?attachmentid=385951&dateline=1357256003

[sweetbmxrider]

Kinda looks like the dielectric grease that should be there but its tough to say it is exactly. Does it seem to be consistent with what you would consider grease?

[GhostDakota]

Kinda looks like the dielectric grease that should be there but its tough to say it is exactly. Does it seem to be consistent with what you would consider grease?

Negative. It's like battery terminal corrosion. It looks as though water has dripped down between the hood/fender, onto the ECU, into the connections, then down further as well.

[sweetbmxrider]

Ok, well that's not good obviously. Have you checked the seals on the connectors? I can only imagine if you are seeing corrosion there that water has gotten into the pcm as well.

[GhostDakota]

The seals all good great. That's what worries me...

I just spent 2.5 hours working on it. I removed the ECU connectors from the ECU and cleaned them with electrical cleaner spray. Then, I removed the 4 easily accessible grounds: Driver side strut tower, driver side front next to the intake, passenger side strut tower, passenger side front next to the intake. I filed down the grounds metal contacts and wire brushed them as well.

Started up the car and it ran basically 99%! I took it for a 0.5 mile drive and it slowly got worse. At stops it would almost stall. I brought it back and parked it. It seemed to get worse the longer it was running. However, overall it seems much quieter and seems to run much smoother as well.

This is all on the "new" ECU from my buddies '98 Camaro SS. Should I be cleaning out my other ECU (Which is remanned it seams) and try to run it again?

[Stevoone]

Have you checked back pressure on the known bad converter yet? I saw this mentioned on the last page, not sure if its been done yet.

[GhostDakota]

Have you checked back pressure on the known bad converter yet? I saw this mentioned on the last page, not sure if its been done yet.

All 4 o2 sensors are operating correctly per my buddy with his expensive SnapOn scanner (He's an engine builder). The temps (Front and rear on the cats) are within range for a properly operating cat. I did not check further than that.

[JL8Jeff]

It sounds like the computer is learning and making adjustments, but something is still not reading right (sensor) or the injectors still aren't firing. The reman ECU might be a clue that there has been a problem previously so maybe look for any electrical items that might have been replaced. I still suspect the wiring harness might be messed up at this point. And the corrosion means the seals were leaking at some time, they might have been replaced before you got the car.

[WildBillyT]

Rick, perhaps now is time to start pushing.


Joking aside, I'd start cleaning some of the electrical connections if they look corroded. And check your ground straps just because.

[sweetbmxrider]

Does this thing have an egr or no?

[GhostDakota]

Thanks fella's. A guy was recommending crank and cam position sensors. He said his car did the exact thing mine is doing right now. I may buy a Walker Y pipe through work just to get rid of the supposed bad cat, and also do those two sensors?

Is there any way for me to test the crank and cam sensors?

I cleaned up the ECU connections on the remanned ECU, and will clean up the harness connections on the car and try the reman again.

EGR are the two tubes coming off the exhaust manifold, right? If so, it does have them.

[JL8Jeff]

The EGR is only on the passenger side up on the front of the engine going into the front of the exhaust manifold, the AIR tubes are on both sides and have the check valves. The check valves can go bad (and often do). The air should only be able to go into the manifold and not come back through.

[GhostDakota]

Thanks, Jeff. FWIW: I ordered the Walker OR-Y through my work. It should be here within 1-2 weeks.

[GhostDakota]

New Walker Y-Installed. Still running like ass:
http://pafirefighter11.smugmug.com/photos/i-V5ZSg58/0/XL/i-V5ZSg58-XL.jpg

http://pafirefighter11.smugmug.com/photos/i-pqj6jPw/0/XL/i-pqj6jPw-XL.jpg

Driver side:
http://pafirefighter11.smugmug.com/photos/i-Vmmq4qj/0/XL/i-Vmmq4qj-XL.jpg

Pass. side:
http://pafirefighter11.smugmug.com/photos/i-4JDXLCq/0/XL/i-4JDXLCq-XL.jpg

Driver side pipe is this short:
http://pafirefighter11.smugmug.com/photos/i-FqHR3JV/0/XL/i-FqHR3JV-XL.jpg

Had to weld in some pipe:
http://pafirefighter11.smugmug.com/photos/i-TpGqtZk/0/XL/i-TpGqtZk-XL.jpg

http://pafirefighter11.smugmug.com/photos/i-nrDnLbD/0/XL/i-nrDnLbD-XL.jpg

http://pafirefighter11.smugmug.com/photos/i-Rp8CfRk/0/XL/i-Rp8CfRk-XL.jpg

[GhostDakota]

I took the car to a local Performance shop that does tuning. He hooked it up to his laptop, fired it up and ran his programs. He said it's running lean (though smells of unburnt fuel). It's missing on 5, 7, and also on 6, 8. More-so on 5, 7. Driver side front o2 is bad. I have a new one that I will be installing to see what it does. Hopefuly is resolves some of the issues, if not everything. I may change the plugs again as well since these brand new ones may be fouled...

[GhostDakota]

I replaced the front driver side o2, recet ECU. Runs better, not the fix though. It has some weird electrical things going on. Shifted into reverse and the speedo jumped to 20 MPH. Opened the cutout and the RPM's jumped 300 RPM. 2 weeks ago the speedo was reading WAY low. 42 MPH when doing 70 for example.

[GhostDakota]

Just wanted to update the latest. My buddy and I at work checked the wires running from the PCM to the coils. They all have continuity per our multi-meter. So, the wires are good from the PCM to the coils. One more thing ruled out I guess....

[WSex]

Just wanted to update the latest. My buddy and I at work checked the wires running from the PCM to the coils. They all have continuity per our multi-meter. So, the wires are good from the PCM to the coils. One more thing ruled out I guess....

could have continuity but doesnt rule out it being shorted.

i think youre best bet is to rewire all the coils.

[GhostDakota]

I finally threw in the towel. I just dropped it off at a local shop this morning. We'll see what they fine.

[GhostDakota]

I'll do some more looking and a compression test soon.

I dropped it off at another local shop today. They put some time into it and are going to put some more work into it next week.

Just some info from my Torque app...

Freeze frame information:
------------------
Fuel Status = 0 byte
Engine Load = 6.667 %
Engine Coolant Temperature = 197.6 °F
Fuel Trim Bank 1 Short Term = 16.406 %
Fuel Trim Bank 1 Long Term = 24.219 %
Fuel Trim Bank 2 Short Term = -5.469 %
Fuel Trim Bank 2 Long Term = 13.281 %
Intake Manifold Pressure = 6.382 psi
Engine RPM = 1,608.25 rpm
Speed (OBD) = 34.797 mph
Mass Air Flow Rate = 155.214 cfm
Throttle Position(Manifold) = 11.373 %

End of report.

41* timing advance?!
http://pafirefighter11.smugmug.com/Automotive/1998-Pontiac-Trans-Am/i-N2rbV4m/0/L/487345_10151269396016080_705252989_n-L.jpg

[chrisfrom nj]

i thought you pushed it off a cliff or drove threw a river and got stuck

[sweetbmxrider]

Bring the engine up to 3-3500 and see what the short term fuel trims do.

[GhostDakota]

Bring the engine up to 3-3500 and see what the short term fuel trims do.

I'll do that next. Here's what I have at the moment...

Freeze frame information @ idle:

------------------
Fuel Status = 0 byte
Engine Load = 2.353 %
Engine Coolant Temperature = 226.4 °F
Fuel Trim Bank 1 Short Term = -10.938 %
Fuel Trim Bank 1 Long Term = -7.812 %
Fuel Trim Bank 2 Short Term = -14.844 %
Fuel Trim Bank 2 Long Term = -8.594 %
Intake Manifold Pressure = 6.382 psi
Engine RPM = 755.5 rpm
Speed (OBD) = 0 mph
Mass Air Flow Rate = 53.824 cfm
Throttle Position(Manifold) = 0.392 %
End of report.

Per Tom Oates:
http://pafirefighter11.smugmug.com/photos/i-kjpLGwC/0/XL/i-kjpLGwC-XL.jpg

[sweetbmxrider]

What have I been saying?

:lol:

[grazi]

I would just unload it for cheap so you don't have to deal with it anymore. PM Me........:wink:

[stealth355tpi]

Didn't read through everything but if the wiring all looks good, how about the computer? My 98 had some weird problems but somehow once I grounded the computer everything worked fine.

[Mike]

Didn't read through everything but if the wiring all looks good, how about the computer? My 98 had some weird problems but somehow once I grounded the computer everything worked fine.

You should read through everything.

[WSex]

ghostdakota, compression test is pointless imo. is say swap the harness. if anything you can resell the harness.
have the people youve taken the car too used an oscilloscope?

[BarneyMobile]

ghostdakota, compression test is pointless imo. is say swap the harness. if anything you can resell the harness.
have the people youve taken the car too used an oscilloscope?

How is a compression test pointless?

[LTb1ow]

I replaced the front driver side o2, recet ECU. Runs better, not the fix though. It has some weird electrical things going on. Shifted into reverse and the speedo jumped to 20 MPH. Opened the cutout and the RPM's jumped 300 RPM. 2 weeks ago the speedo was reading WAY low. 42 MPH when doing 70 for example.


Sounds like your car is wired like hell if your cutout is messing up dash cluster signals..


What have I been saying?

:lol:

I read the whole thread, and could not figure out what you have been saying.

[GhostDakota]

I did state earlier that I swapped ECU's from my buddies '98 Camaro SS. Didn't change anything.

So if you're just reading this, #5 and #7 are the misfiring cylinders.

I purchased a compression tester today:
http://pafirefighter11.smugmug.com/photos/i-nG5D8Bc/0/XL/i-nG5D8Bc-XL.jpg

Only had time to do 4 cylinders, but everything checked out fine:
http://pafirefighter11.smugmug.com/photos/i-hVqTDN4/1/XL/i-hVqTDN4-XL.jpg

And the plugs ... 1-3-5-7:
http://pafirefighter11.smugmug.com/photos/i-2DFpjGR/0/XL/i-2DFpjGR-XL.jpg

[GhostDakota]

I don't know what Mode $06 test results are but here are mine:

Mode $06 report generated by Torque for Android
================================================

Vehicle VIN: Not present
Vehicle Manufacturer: Unknown
Vehicle Calibration ID: Not present

Unit and scaling information are not supplied with the data from the ECU for this type of vehicle. Consulting the manufacturers service book for this information is recommended.

Test report:
------------------
TID:$02 CID:$04
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$10
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$11
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$12
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$20
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$21
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$26
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$30
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$31
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$36
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$40
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$46
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$04 CID:$20
- High sensor Voltage for switch time calculation
Max: 32,766
Test result value: 32,770
FAIL
----
TID:$04 CID:$30
- High sensor Voltage for switch time calculation
Max: 32,766
Test result value: 32,770
FAIL
----
TID:$06 CID:$35
- Lean to Rich sensor switch time(calculated)
Max: 62
Test result value: 19
PASS
----
TID:$06 CID:$41
- Lean to Rich sensor switch time(calculated)
Max: 104
Test result value: 35
PASS
----
TID:$06 CID:$55
- Lean to Rich sensor switch time(calculated)
Max: 67
Test result value: 42
PASS
----
TID:$06 CID:$61
- Lean to Rich sensor switch time(calculated)
Max: 106
Test result value: 50
PASS
----
TID:$07 CID:$0c
- Minimum sensor Voltage for test cycle(calculated)
Max: 0
Test result value: 65,491
FAIL
----
TID:$07 CID:$0d
- Minimum sensor Voltage for test cycle(calculated)
Max: 1
Test result value: 65,491
FAIL
----
TID:$02 CID:$04
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$10
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$11
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$12
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$20
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$21
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$26
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$30
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$31
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$36
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$40
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$46
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$04 CID:$20
- High sensor Voltage for switch time calculation
Max: 32,766
Test result value: 32,770
FAIL
----
TID:$04 CID:$30
- High sensor Voltage for switch time calculation
Max: 32,766
Test result value: 32,770
FAIL
----
TID:$06 CID:$35
- Lean to Rich sensor switch time(calculated)
Max: 62
Test result value: 19
PASS
----
TID:$06 CID:$41
- Lean to Rich sensor switch time(calculated)
Max: 104
Test result value: 35
PASS
----
TID:$06 CID:$55
- Lean to Rich sensor switch time(calculated)
Max: 67
Test result value: 42
PASS
----
TID:$06 CID:$61
- Lean to Rich sensor switch time(calculated)
Max: 106
Test result value: 50
PASS
----
TID:$07 CID:$0c
- Minimum sensor Voltage for test cycle(calculated)
Max: 0
Test result value: 65,491
FAIL
----
TID:$07 CID:$0d
- Minimum sensor Voltage for test cycle(calculated)
Max: 1
Test result value: 65,491
FAIL
----

End of report.

[WSex]

I did state earlier that I swapped ECU's from my buddies '98 Camaro SS. Didn't change anything.

you swapped the ecu but not the harness itself

ok i know you have tried different coils. but heres something you should try.
undo the brackets for the coils and swap sides. plug it in and start it to make sure its not the wiring that is on the bracket.
if the misfire is still on 5 and 7 then we can definitely rule out the coils and wiring that is on the coil brackets.


and again have you hooked up an oscilloscope?

[Mike]

I did state earlier that I swapped ECU's from my buddies '98 Camaro SS. Didn't change anything.

you swapped the ecu but not the harness itself

He was responding to the guy that said swap computers

[WSex]

He was responding to the guy that said swap computers

i know


but everything leads to shorted or open wires. continuity tests will only tell you its open or not but wont show shorts. theres only one thing to do pull the ignition harness and rewire it. seems like ghostdakota is avoiding it at all costs.

[GhostDakota]

i know

but everything leads to shorted or open wires. continuity tests will only tell you its open or not but wont show shorts. theres only one thing to do pull the ignition harness and rewire it. seems like ghostdakota is avoiding it at all costs.

Yep, I'm completely broke right now between both Trans Ams and my Jeep being down. No money for a harness, no time to do it, and nowhere warm to really do it either. I get hit or miss garage use time at work when it's not being used.

[sweetbmxrider]

http://www.examiner.com/article/using-mode-6-data-to-ensure-happy-customers

He used a good example in there. Its like taking a test and passing with a 71 or failing with a 69. Mode 6 tells you by how much you are setting or not setting a code. I think what you posted seems to be for o2's but I am really uncertain. Hell it could be for the rear o2's and it could all be failing because its tuned out. Its not my forte, its just my thoughts.

[WSex]

Yep, I'm completely broke right now between both Trans Ams and my Jeep being down. No money for a harness, no time to do it, and nowhere warm to really do it either. I get hit or miss garage use time at work when it's not being used.

i know but youre dancing around the problem hoping it'll fix itself. when you tried the lq4 coils did you swap just the coils or the bracket with the coils on it?

[Mike]

I have a harness you can troubleshoot with but it's a 99

[WSex]

I have a harness you can troubleshoot with but it's a 99

will work if he uses his ecu out of his 99 i think i guess

[GhostDakota]

I have a '98 and '01.

[WSex]

I have a '98 and '01.

99-02 is same
98 is different.

[GhostDakota]

Quick question. PCM wiring harness. What color is the ground wire in the harness for the PCM? Seems it's white on LT1's... Black/white - ground jumper (I have a pdf but cannot attach it due to size limitations on attachments)? I want to get at it and reroute it. There is no way I'm getting to the back of the head anytime soon. I'm 6'4", 215 and my arms don't really fit. I don't have lift access anytime soon either. Closest garage I have access to is 25 miles away.

[WSex]

borrow the harness and comp. just hook up ignition fuel and maf the battery and some grounds. start it up and see if it misfires
will take you less than 30 in your driveway

[GhostDakota]

borrow the harness and comp. just hook up ignition fuel and maf the battery and some grounds. start it up and see if it misfires
will take you less than 30 in your driveway

I would if I could. I'm west of Philly and my only working vehicle is my motorcycle.

[GhostDakota]

EFI Live & my Trans Am will be meeting tonight...

[GhostDakota]

Took it to a fellow LS1 owner. He hooked it up to his EFI Live. He stated: "I hooked up HPtuners and monitored current misfires and #5 and #7 are misfiring badly. It sounds like to me he's either got a broken valve spring, or two, or a bent valve. I told him to get the driver's side valve cover off asap and see what's up before he does anything else. "

[WSex]

Took it to a fellow LS1 owner. He hooked it up to his EFI Live. He stated: "I hooked up HPtuners and monitored current misfires and #5 and #7 are misfiring badly. It sounds like to me he's either got a broken valve spring, or two, or a bent valve. I told him to get the driver's side valve cover off asap and see what's up before he does anything else. "

you havent removed the valvecovers yet?
bent valve? thought compression test was good.

[WSex]

ghostdakota bring it to me. ill diagnose it. + i have the harness from my 98 laying in the garage.

[GhostDakota]

Compression was good. I did a 4 puff test which GM suggested. I was unable to see the gauge until I stopped the test. A GM tech on another forum said he has seen this twice in the past. One was a bad PCM to ground wire. The other was a bent/broken valve spring. Compression can still be good with a bent/broken valve spring per what he said. It is just something I would notice on the 1st puff, not after 4. Of course he tells me that now.

I appreciate the offer! Harrison is approx. 2 hours+ away from me. My zip is 19380. That's a long drive in this car with the way it is currently running.

[WSex]

pull the covers start the car and use your orbital scan tool to diagnose.

[GhostDakota]

Okay, photos of the valve springs:
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-g2zvPxF/0/XL/IMAG0156-XL.jpg

7:
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-JF2nzrN/0/XL/IMAG0158-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-RgkBnkT/0/XL/IMAG0163-XL.jpg

5:
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-THtNQVR/0/XL/IMAG0164-XL.jpg

3:
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-Gr3wj7j/0/XL/IMAG0165-XL.jpg

1:
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-8cnZX4M/0/XL/IMAG0166-XL.jpg

Valve cover:
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-NqKPV2r/0/XL/IMAG0167-XL.jpg

[stealth355tpi]

do any feel loose? just curious if it ever spit out the needle bearings from the rockers. from the pics cant really see anything wrong, how about the other side? might as well check the pushrods while your in there, thats fast and easy.

[GhostDakota]

do any feel loose? just curious if it ever spit out the needle bearings from the rockers. from the pics cant really see anything wrong, how about the other side? might as well check the pushrods while your in there, thats fast and easy.

I did this earlier, after work. I only have very limited garage time. Had to pop the cover, check it, and pop it back on. Everything seemed pretty tight. Didn't get a chance to get to the passenger side, but the driver side is the issue.

[stealth355tpi]

yea i forgot 5&7. let me ask you this. i know its stupid but are the locking pins on the pigtail that powers the injector. i just had a miss that would come and go on my dd. moved coils arounds, checked plugs and nothing. finally after staring at it for awhile going wtf. i noticed all the clips on the injectors were missing from the previous owner so the pigtail jump around causing my miss.

[GhostDakota]

They are! Not an odd question either. I noticed when I plugged the coils back in that the clips held the plug better than without, so I made sure all 4 were are in use.

[stealth355tpi]

damn, running out of ideas haha. sticky injector maybe? ill have to think some more on this one.

[GhostDakota]

damn, running out of ideas haha. sticky injector maybe? ill have to think some more on this one.

I swapped the injectors a couple times. I added 2 injectors from a '98 Camaro SS into the 5 & 7 locations. Didn't do anything. I swapped the 5 tonight to the 1 and nothing changed. It's still on 5 & 7.

[stealth355tpi]

so you still dont know wither its fuel or spark? maybe try a injector test noid or start pulling the wire loom off to look for broken or chewed wires.

[GhostDakota]

so you still dont know wither its fuel or spark? maybe try a injector test noid or start pulling the wire loom off to look for broken or chewed wires.

Ran the noid a few times. No issues.

Per GM:
http://pafirefighter11.smugmug.com/photos/i-kjpLGwC/0/XL/i-kjpLGwC-XL.jpg

[WSex]

did you start the car withthe cover off to confirm it wasnt mechanical. have you swapped the whole coil bracket?

[sweetbmxrider]

Have you tried swapping the ignition wires around?

[GhostDakota]

There is spark per GM. I swapped in an LQ4 row of coils and that didn't change anything. It's not the coils or those wires. I did not start the car with the valve cover off. I didn't know to do that. I'm definitely not a mechanic lol.

I am going to swap in the Crank Position Sensor from my '01 to see if that changes anything. My buddy had his go bad on a few vehicles and it causes similar issues.

[sweetbmxrider]

So the actual ignition wires have been moved to different cylinders or completely replaced?

[V]

not sure if feasible... but could you program the ecm firing over such that 5&7 become 1&3? THEN switch the plug wires and injector connectors so that actual firing order is correct?... then if it still shows a 5/7 miss you know its mechanical, if now 1/3 you know its electrical.

[Stevoone]

May be a waste of time but have you had a vacuum gauge on the engine (must be a mechanical gauge with a needle)? Different conditions will cause the needle on the gauge to react differently.

http://www.broncolinks.com/gallery_images/VacuumGaugeDiagnosisCraigU.JPG

[GhostDakota]

Thanks guys - just wanted to post this. Finally got to #8 tonight... wow:
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-mCsQBLs/0/XL/IMAG0173-XL.jpg

Car idles a lot better, drives a lot better, but is still missing on 5 & 7.

[WildBillyT]

That may give you some more insight into cyls 5 and 7. That's a lot of crud.

Maybe a top end clean/seafoam is in order?

[WSex]

pull the covers and start the car

[sweetbmxrider]

Yeah that's a lot of carbon deposit. Did it reek of fuel? I would do a top end clean or two.

[GhostDakota]

UPDATE: SO, I think I may have found the issue, or a big part of it. I decided today to check things I have checked already, just in case I missed something, or see if anything changed. On my way home I stopped, unplugged the MAF, reset the codes on the PCM with my Torque app, and drove. WOW.... what a difference. CEL is not blinking, it's not even on anymore. I drove it 25 miles home. The car still has minor hesitation but no big misfire. Check out these screen shots:

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-cnMvCnt/1/O/screenshot.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-cWvXsWh/1/O/screenshot.jpg

I'll order up a new MAF and see if that fixes things completely!

[WildBillyT]

Is your MAF descreened? I forget if I asked that.

[GhostDakota]

Is your MAF descreened? I forget if I asked that.

The '01's is, the '98 is not.

[Mike]

Bad Maf does some crazy stuff. Just changed the one on the trailblazer. It was causing major shifting issues

[donnj]

glad your getting closer to fixing this, black magic stinks

[sweetbmxrider]

I'd be leery of that fixing the issue, I hope it does though! Unplugging the maf will force the computer to use default spark and fuel tables. I'm not sure it will be able to calculate fuel trims either since its not reading air in. I could be mistaking though and I hope it is the issue!

[WSex]

Yeah if it was a bad maf it wouldn't be a constant 5&7 miss


Now the carbon deposit looks to be signs of babying the car way too much

[GhostDakota]

Whatever the case, after 45 minutes of driving (25 miles) the CEL is off. EVERY other time I reset the PCM codes the CEL light came on within 1 minute, and flashed immediately when it hit 30+ MPH. I need to hook it up to EFI Live again and see what's going on.

[grazi]

Post #36. You said you checked all that out. ????????

[grazi]

Doesn't the car remain in open loop when maf is unplugged which means it not using the O2 readings.

[WSex]

Doesn't the car remain in open loop when maf is unplugged which means it not using the O2 readings.

ehhhhh it goes to its back up and uses the map sensor

[GhostDakota]

It's definitely not fixed 100%, but the blinking misfire is gone. No P0300 code. Only code is for the MAF being disconnected. When it's warm it still idles pretty rough and wants to die at stops (though it hasn't). But once it's warmed up I'd say it's about 85% better than with the MAF plugged in. I'm going to have my AIR and EGR tuned out, to see if that further helps things as well. Anyone have a confirmed working '98 LS1 MAF for sale? :P

[stealth355tpi]

Try switching the maf from your other car then and see what it does.

[WSex]

i hve a maf for sale. on my forsale thread.

[GhostDakota]

I'm under the impression that they are not the same? '98-'00, '01-'02. I did try swapping MAF's several months ago and it didn't fix anything. The other one is descreened and probably bad itself.

Let me test one from a buddy to verify it is the MAF. If that's the case I'll start looking to pick one up.

[stealth355tpi]

I've never heard of the maf being any different unless you have an aftermarket one that's bigger.

[GhostDakota]

I've never heard of the maf being any different unless you have an aftermarket one that's bigger.

Gotcha, thanks. I did see some JET ones, etc., that were specific to 2-3 year ranges. I couldn't find any GM ones on the sites.

[GhostDakota]

Random question... I know carb cleaner is obviously flammable but should it catch fire when spraying it on the engine compartment? lol. I mean, that's a sign of a spark somewhere it shouldn't be, right? The motor wasn't really hot when I sprayed it either...

[BonzoHansen]

Random question... I know carb cleaner is obviously flammable but should it catch fire when spraying it on the engine compartment? lol. I mean, that's a sign of a spark somewhere it shouldn't be, right? The motor wasn't really hot when I sprayed it either...

what are you trying to accomplish??

[WildBillyT]

Are you looking for vacuum leaks?

[GhostDakota]

Vacuum leak check, yes.

Also, one of the PCV or breather hoses that runs from the driver side valve cover to the passenger side (?) valve cover deteriorated. It has come apart completely. I temp. taped it back up. I'm burning a ton of oil. It's blue smoke, and pretty thick. Not Seafoam thick, but it's a fair amount. What do I need to replace this tube, and is this related to the burning oil?

[JL8Jeff]

The LS1 can pull a lot of vacuum and they are known for pulling oil vapors through the pcv into the intake. That might explain your #8 spark plug. Check the pcv hose and see if it is really oil soaked.

[NastyEllEssWon]

you should just use a propane torch. just turn the valve and blow a little bit of propane around. it'll do the same as the carb cleaner but wont be dangerous :D

[GhostDakota]

Thanks guys. Propane isn't as much fun as the carb cleaner haha.

The PCV hose is soaked through and gummy, coming off the driver side valve cover. So much so it is sliced and I had to tape it back.

This is the PCV fix I'll be undertaking today I think: http://www.bowlingss.com/Mods/SMH%20PCV%20Modification%20for%20LS1.mht

[donnj]

any news Rick?

[WSex]

any news Rick?

down the cliff..

[GhostDakota]

Another MAF didn't change anything. I think the MAF is just a piece in the puzzle. With the MAF plugged in it's almost instantly a P0300 code. When unplugged, it is gone.

[WildBillyT]

Did you do the PCV fix?

If that hose was brittle and leaking vacuum that could certainly cause a ton of problems.

[GhostDakota]

I did do the PCV fix. Nothing changed.

I'm at the point where I am driving a Ford now... '13 "Gotta Have It" Green... I'm going crazy...

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-VPg4KSK/0/XL/IMAG0210-XL.jpg

It's kind of nice driving a comfortable, reliable vehicle...

[donnj]

:shock:

[GhostDakota]

:shock:

Don't worry... I'll be right back into the '98 once I get the bastard fixed. Otherwise, once it warms up, the '01 is getting new head gaskets and will become my DD, along with my bike, 'til the '98 is fixed.

[donnj]

any updates?

[GhostDakota]

Nada. I drove it 30 miles today. It's okay on the highway, idles like it has a cam. I've basically given up for now...

[NastyEllEssWon]

you know i actually just read through this entire thread and it just dawned on me you should check your cam sensor.

[WSex]

you know i actually just read through this entire thread and it just dawned on me you should check your cam sensor.

hmmmm not a ad idea

[GhostDakota]

Cam and crank sensors are both next. Thanks WSex!

[NastyEllEssWon]

Cam and crank sensors are both next. Thanks WSex!




wont be crank sensor or else youd be having problems with it shutting off randomly. cam sensors can do the same thing but its more of a possibility that during that cars life someone screwed it up from having the intake off.

lol also my names not wsex ;)

[GhostDakota]

wont be crank sensor or else youd be having problems with it shutting off randomly. cam sensors can do the same thing but its more of a possibility that during that cars life someone screwed it up from having the intake off.

lol also my names not wsex ;)

haha I was thanking him for a PM he sent. I've seen some crank sensor issues on Tech that have problems similar to mine. Have yet to see a cam sensor thread showing the same thing though, but who knows. I'm doing the head gaskets in the '01 a week from this weekend. The '98 is getting back burner status at that point.

[GhostDakota]

PROBLEM FOUND! Check the photos for the work done yesterday... All are cell photos so the quality sucks:

Went to do a compression check:
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-54nPSt3/0/XL/IMAG0383-XL.jpg

Then decided to pull the valve covers - passenger side:
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-S9CrqkR/0/XL/IMAG0384-XL.jpg

A little closer:
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-P5c9bVQ/0/XL/IMAG0388-XL.jpg

Time to rip the top end apart:
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-chGJrTP/0/XL/IMAG0390-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-3BmwmWL/0/XL/IMAG0395-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-JxVLnr3/0/XL/IMAG0397-XL.jpg

My buddy Steve has his old LS1 with 55k miles on it (He has his LS6 now) so we're using his heads, springs, rockers, etc:
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-4GvXqrt/0/XL/IMAG0391-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-tGtWjH9/0/XL/IMAG0392-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-VRJcGGg/0/XL/IMAG0393-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-s3MxzTB/0/XL/IMAG0394-XL.jpg

We're hoping to have the heads and everything swapped over by Saturday or Sunday at the latest. We ordered all the gaskets needed from GM today. Should be here today or Saturday. I can't wait to get this thing back on the road!

[Featherburner]

Did you order new head bolts?

[sweetbmxrider]

Finally!!! While you have the heads off, you'd be foolish to not recam it :)

[GhostDakota]

John, all hardware needed is on order, yes.

BMX: I don't have time to upgrade anything unfortunately. The car has to be out by Sunday. Going to heads with 50k miles, cleaning the pistons of carbon buildup, and putting everything back together should be more than enough improvement compared to what I have now lol.

[sweetbmxrider]

:lol: I hear ya man.

[LTb1ow]

You are reusing old springs, even after having a spring fail on yours...?

[GhostDakota]

You are reusing old springs, even after having a spring fail on yours...?

The springs that failed are not stock springs, not stock retainers, etc. I'm completely comfortable reusing stock GM springs and retainers, etc, yes.

Someone was in there before and changed out most everything on the passenger side.

[GhostDakota]

Just throwing this out there... Does this look like a cracked rocker?

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-kM3RRBK/0/XL/Rocker-Close-XL.png

[WSex]

i have extra rockers and springs and all that dumb stuff

[sweetbmxrider]

Take it off and inspect it.

[WildBillyT]

Take it off and inspect it.

THIS. A thousand times THIS.

[GhostDakota]

The springs, valves, heads, etc., are coming off. The ones from my buddies car are being cleaned and prepped now. I'll be looking at possible spring failures once we get the old heads off.

[GhostDakota]

The rocker is not cracked. Strange optical illusion I guess. More progress today. Heads are off, everything is cleaned, getting ready to put the new heads on... Photos from today:

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-PjDSMwx/0/XL/IMAG0405-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-hFX7jBj/0/XL/IMAG0407-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-c3xQpMk/0/XL/IMAG0408-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-jnZ3H8j/0/XL/IMAG0410-XL.jpg

Oh haiii... Found 2 of these - of course we didn't verify which cylinder(s) they were from:
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-vtsLjZP/0/XL/IMAG0412-XL.jpg

Looks like aftermarket springs, retainers... Possibly a head off of a newer Trans Am, Corvette, etc.?
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-GRLBNDv/0/XL/IMAG0413-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-nXMStrB/0/XL/IMAG0414-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-QLSjfTV/0/XL/IMAG0415-XL.jpg

Heads are going back on tomorrow or during the week (depending on family plans).

[sweetbmxrider]

:shock:

[GhostDakota]

And a couple non-cell phone shots with my Nikon D2x and Tamron 17-55 f/2.8:

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-r8rsHsb/0/XL/BCM_7828-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-bszQJQ3/0/XL/BCM_7825-XL.jpg

[GhostDakota]

Let me also add. Valve float! It was to the point where the pistons have a slight gouge in 'em from the valves, but no other damage.

[GhostDakota]

Some progress last night:
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-FvDxXJg/0/XL/IMAG0424-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-XssPzDJ/0/XL/IMAG0425-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-d7LT6z7/0/XL/IMAG0426-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-SXXbP2j/0/XL/IMAG0427-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-pv3V6HC/0/XL/IMAG0430-XL.jpg

[GhostDakota]

SHE RUNS!!

Video here:
http://www.youtube.com/watch?v=MfY7E8NGv10


Some more progress (cell phone) shots from yesterday:

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-9JMkDs5/0/XL/IMAG0433-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-4KWf72J/0/XL/IMAG0435-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-rzMZbcF/0/XL/IMAG0436-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-WWddcvk/0/XL/IMAG0437-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-93XDhJv/0/XL/IMAG0438-XL.jpg

Bolting the exhaust back together:
http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-NWKP4kN/0/XL/IMAG0440-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-kjBLXvz/0/XL/IMAG0441-XL.jpg

http://pafirefighter11.smugmug.com/Automotive/98-Trans-Am-Misfire/i-kDcwCPk/0/XL/IMAG0442-XL.jpg

We still need to add some coolant and a coolant temp. sensor.

[GhostDakota]

Video from yesterday of intake & engine area, and exhaust (Burning up some oil! No longer smokes though):
http://www.youtube.com/watch?v=PXdatfP3cEY

[sweetbmxrider]

Did you change the oil?

[GhostDakota]

Did you change the oil?

Of course. New oil, new coolant.