Problems @ 2,500+ RPM's

[ar0ck]

I don't know how to explain this better then once my car is warmed up it will not rev past 2,500+ RPM's while driving. When the car idles its completely fine. It happens in all gears and at all speeds in the RPM range above 2,500. I took a video if it to help people who haven't seen my car. If the car is still cold I can run it to red line without any problems but maybe a few more minutes down the road it becomes intolerable to drive.

Right now I am currently running stock 24# injectors with a newly installed Racetronix 255 fuel pump. I have Racetronix 38# injectors but I'm waiting to install them until i hear back on cost to have the computer re-tuned by MadZ28. I have this feeling that its fuel or tune related because I figure if it was ignition I would notice it even at idle. I plan on performing a basic tune up next weekend. Does anyone have any suggestions?

[bubba428]

O O O I KNOW THIS ONE!!! Ok, a month ago at Atco my car did the same thing, and it caused me to run a horriffic time. You have a fuel problem. I would check that 255 pump out first, to make sure its connected and working properly, then give the lines a look over. Now If your the kinda person that waits till just befor empty to fill the gas tank, you most likely need a new fuel filter.

[johnjzjz]

a bad cat can also cause that -- jz

[ar0ck]

I just finished installing the fuel pump this morning and it runs fine at idle, and is also able to rev fine at idle. The fuel filter was replaced in November right before I spun a bearing in the old motor.

I have Pacesetter Long Tubes with an Off-Road Y-pipe, 3" cut-out, and then a 3" magnaflow system for my exhaust.

I Wonder if it is too rich. I was reading that when it is cold the O2's don't assist in fuel regulation. So once they warm they do. So if for some reason they are seeing WAY too much fuel they will back the fuel off, right?

[bubba428]

yes they would...so are you saying the problem is gone or still persistant

[ar0ck]

The RPM's that I can rev past get lower & lower the longer I drive the car. I'm going to replace the MSD blaster coil, Opti cap & rotor ,and change the plugs this week.

[Batman]

What Mods do you have? Sounds like it is running out of fuel, with stock injectors in there if you have a cam and especially heads you are going to be maxing them out, or th eopti is ka-put. How old is the opti? Might be a good time to upgrade. If you can find someone with a Fuel pressure gauge with a long hose hook it to the fuel rail and run it up under the cowl and into the car so you can see it while you are driving and run it up and look for a drop in pressure.

[foff667]

he's not going to max out his injectors at 2500 rpms lol...my .02 is that it very well might be the opti.

[ChickenLittle]

sounds like an Opti to me

did it on al of my LT1s and that's what it was every time

[ar0ck]

The Opti was a bran new Summit unit. I had it in the car since October, and I have been having this problem ever since. Then a month later I spun a bearing so I reused the same unit. I have a spare MSD Cap & Rotor though just incase. Tonight I'm going to change the MSD Blaster-Coil I have on the car along with the mass air sensor for good luck (old one is de-screened)

[ar0ck]

Ok I changed the blaster coil and it did not fix anything. I went over all the spark plugs & wires, the wires are fine, they are not touching any heat sources, nor are they arching. The spark plugs are definitely fouled up though. They were put in last month with no more then 200 miles on them.

I'm guessing it must be the opti then. But I'm not sure if just replacing the cap & rotor is going to do the trick? I don't want to have to tear it down and not be sure this is going to fix a dam thing.

What a pain in my ass. I haven't enjoyed this car WOT since the end of August.

[Batman]

Could be bad plugs if they are really ******. What color are the electrodes?

[Little G]

Could be the flux capacitor.

g

[ar0ck]

Originally Posted by Little G

Could be the flux capacitor.

g

I wish it was that simple.

I unplugged the 02 Sensors and re-set the computer and it ran the same. It didn't let me rev as high though at idle.

[bubba428]

dude you have a fuel delivery isue...change the filter, check the lines

[ar0ck]

Originally Posted by bubba428

dude you have a fuel delivery isue...change the filter, check the lines

Like I said, how can it be fuel when it runs fine for about 10-20 minutes? I had the fuel filter replaced in November on Heads & Cam combo #1 on the stock fuel pump and I spun a bearing 200 miles away from home. The instant I drove away with a BRAND NEW AC DELCO fuel filter, the problem was still there. This H&C set up has been in the Car since October doing the same exact **** on the same PCM on two different motors with the same exact combination save for a larger fuel pump. I changed ALOT of things when I built it the first time so there are so many variables it blows my mind.

You need to explain this because I am not just going to piss away money on something that has been tested already.

[ar0ck]

I swapped computers with someone i know with a similar set-up and the problem was still there so tomorrow I'm doing an Opti.

[SteveR]

Turn it on in your driveway and wait for it to heat up. Then try reving the motor in neutral and make sure its not your trans. I had a similar problem a few years ago and at higher rpms, the failing bearings made a much more pronounced sound. Just something else to try and hopefully eliminate.

[ar0ck]

Build up on the points probably isn't good. Neither is a burned up optical sensor shield.

[Knipps]

all this talk of your new camera but your pics still come out damn blurry
alex FTL.