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View Full Version : injector help ASAP!!! thanks


transmaro93
11-11-2006, 10:44 AM
hey guys so i started worken t his morning on my MISS.... and i have spark goin to #7 so its not ignition so i think its the injector.... i pulled the #7 injector and no change in running so i connected it back... then i pulled the #5 and it ran even worse than it was... im gonna go down the line in a few mins to fool around with the other ones to make sure the others are ok... SOO... is it strange for an injector to just stop working out of nowhere... especially on a rainy day or is there somthing else i can try besides replaceing the injector to further diagnose the problem.... O and JON if u read this i might pick one of those injectors up off of u unless i decide to replace them all... and to everyone if i replace them how big shoiuld i go its basically stock with headers and exhaust intake stuff like that... thanks in advance guys.....

Silent Z
11-11-2006, 11:01 AM
I would check to see if there is voltage at the injector connector.

deadtrend1
11-11-2006, 11:05 AM
ah, so it was the injector

put a multimeter on the injector, it should be between 11 and 14 ohms

transmaro93
11-11-2006, 11:32 AM
yea i gotta wait till monday tho cause my meter is in my tools box nestled away safely at work.... sucks having only one set of tools... haha if i did replace all the injectors how many lb/hr should i go with...?? whats gonna give me the best performance...?

deadtrend1
11-11-2006, 12:07 PM
you really dont have many mods in your sig to necessitate going to a higher lb.hr. injector, in my opinion. But I'm no expert .....

transmaro93
11-11-2006, 12:21 PM
yea i know that... thatswhy im askingi didnt know if i stronger injector would help get me more power or not... what is the stock lb/hr for the lt1 if u know? thanks

Rob WS6
11-11-2006, 01:47 PM
Stock is 24lb/hr. Plenty of fuel for what you have.

transmaro93
11-11-2006, 02:04 PM
what if i went to 30lb/hr would that hurt anything or is it basicallyjust a waste of money...?

JL8Jeff
11-11-2006, 05:08 PM
I have a set of stock 24 lb injectors if you're interested in them. $50 buys them. You could go with some SVO 24's which are more like 26 lb injectors with the LT1 fuel pressure. If you go up to 30's you will probably need some programming.

transmaro93
11-11-2006, 05:26 PM
ok thanks... im prob gonna buy some new ones just to know that they are new but thanks for your help ill prob end up getten some 24lb/hr's

Pampered-Z
11-12-2006, 07:16 AM
I would suggest just staying woth stock rated (24lb) you don't need anything bigger so your wasting money on the injectors and tuning ( MUST retunw if you change injector size!!!!) . The stock 24lb injectors can handle around 375 - 400HP normally. After market like the ones JeffH has will handle more and they can tolerate higher fuel pressure.

transmaro93
11-12-2006, 09:26 AM
aight thats kool thanks for the reply's guys i erally appreciate the help....

transmaro93
11-13-2006, 05:52 PM
yea so i got into messen around with the injectors after work and i checked the power going to the injector and it was pulsing perfectly so im like yes i guess the injecter is bad or dirty... so i checked the resistance of it after that and that cleared out so now im like o damn.... so i pulled the 7 and 5 cylinders and switched em out (p.s. those things are a b*tch to get back in)... ill have to wait till tomarrow to scann it because everyone was gone and i had no access to the scanner at this time.... before i put the one back in i checked it erally quick on a jump box and it was spitten some fuel out so i donno what to do if it comes out with cyl. 7 missfire.... ahh well thought id let u guys know if anyone out there cares.... hehe

j0n
11-13-2006, 06:02 PM
g/l homie!

transmaro93
11-14-2006, 07:20 PM
ok so i scaned it today and its still missing really bad at #7 so its not the injectors... but i have spark at the plug there but its still says its missing... if i rev it up a little bit all but maybe 2 of the cylinders have slight misses... im leaning toward the opti not working correctly now... i dont mind putting it in seeing as its an adventure iv never done one by my self before... but i want to make sure that it is the problem before i shed out the money... is there anyway to test the optispark by not just haveing spark going out of it cause i have spark out of it im thinking its just not fireing correctly all the time.... this is confusing the ***** out of me heh... im stumped... any help is appreciated... thanks guys

deadtrend1
11-14-2006, 10:55 PM
Dunno if this is exactly what you need to read, but its opti info for thought
http://shbox.com/1/4th_gen_tech2.html#opti_test

If you do decide to replace the opti, I can easily tell you all the steps and things to remove to get to it

JL8Jeff
11-15-2006, 07:28 AM
Maybe see if you can borrow someone else's coil and ignition module and swap them out. On my 96 SS I was getting an occasional misfire on a single cylinder that would then turn into a random misfire. The car ran great so I knew it wasn't a real problem. But I changed out the coil(went with an MSD) and ignition control module(new GM) and never had the problem after that. It very well could be your opti but it might also be a wire, coil or ICM. So try swapping them first if you can find someone to lend you theirs.

j0n
11-15-2006, 08:07 AM
Maybe see if you can borrow someone else's coil and ignition module and swap them out. On my 96 SS I was getting an occasional misfire on a single cylinder that would then turn into a random misfire. The car ran great so I knew it wasn't a real problem. But I changed out the coil(went with an MSD) and ignition control module(new GM) and never had the problem after that. It very well could be your opti but it might also be a wire, coil or ICM. So try swapping them first if you can find someone to lend you theirs.

good call jeff...

brandon i've got a practically new coil/icm already mounted on the bracket and ready to go listed here: http://www.njfboa.org/forums/showthread.php?t=21620

gimme a call

transmaro93
11-15-2006, 05:46 PM
ok guys.... yea i might do that then... ill go on the computer at work tomarrow and see if i can find some good test procedures for that coil/icm... so i might pick that up off of u jon you gonna be around on sat or sun at all maybe ill take a ride up there to pick it up how much u want for it?

deadtrend1
11-15-2006, 06:47 PM
JON, not to hurt your sale, but on my car the coil has a single plug unlike the 2 plug coils that GM used prior. SO im guessing 96-97 obdII coils are different.

JL8Jeff
11-15-2006, 08:25 PM
Yes, the 96/97 coil is different from 94/95. I think MSD is the only one that makes an aftermarket coil for the 96/97 LT1.

Rob WS6
11-17-2006, 11:46 PM
MSD makes them for the 95 style, thats what the car I parted out had. I believe its the same style as the TPI one though.

deadtrend1
11-18-2006, 01:26 PM
MSD makes them for the 95 style, thats what the car I parted out had. I believe its the same style as the TPI one though.

to help end the confusion, here is my 96/97 coil, unlike the pre 96 dual connectors that GM used

http://mywebpages.comcast.net/tstrella/transam/obdiicoil1.jpg

http://mywebpages.comcast.net/tstrella/transam/obdiicoil2.jpg