well you might remember my topic on here a while back about my misfire problem. i've ran cleaner through a few times, replaced all the ignition coils & plugs/wires, and even cleaned the fuel system. the only thing that ever helped a lot was running cleaner through the upper engine (aka seafoam). that happened twice. cleaned it out good, ran it for 150 or so miles and, and the misfire was back again. so now it's pretty obvious. i'm taking it in on wednesday morning to the local *******s to get the fuel injectors replaced. which was they were going to do the very first time, but the warranty company wouldn't cover it! so i'm making a point of collecting my nice assortment of bills and i'm skipping school to wait up there. i'll be there when the mechanic checks it, and if/when the warranty rep. comes, i will be there, and ready to shove my first where the sun doesn't shine. i was told that if they denied the claim at first, then it's not very likely they will cover the repair. i said it doesn't matter, i still want to try. and if the rep. doesn't give in at first i'll say, "hey what's this. oh it's pieces of paper showing all the money i wasted on a reoccuring problem that should have been corrected the first time." nothing would make me happier than finally having this car run beautifully.

 

How many miles on your car? You might consider changing the O2s. I had a misfire/stumbling issues a while and went through the same list of parts..fuel filter, plugs, wires, opti (water leaked onto it), but still had stumbling with random misfires.

Scanned the car and it seems that my driver side front O2 was "lazy". It didn't feedback the correct reading, so the PCM ran the car too lean since it was "compensating" for a rich condition that wasn't real.

Just a thought before you dump the money into changing your injectors. See if your dealership/mechanic will scan the car as it runs and see how the O2s react.

Here's a link to Injuneer's scanmaster user doc. It has a section on how your O2s "should" act.

http://members.aol.com/InjuneerZZ/ScanMast.htm

 

Whoa, that's a sweet write up. Sorry to hijack this one, but uh... is there any write up out there like it for LS1s?

Actually... it looks like a lot of this could apply to the LS1. Is this correct? I'd guess that the numbers might be slightly different, however.

 

i guess i forgot a fairly important detail (a lot of them in this whole ordeal). when i last had my car looked at i told him specifically to look at the EGR valve. he said it was working perfectly. so then he checked all the other sensors--they're perf. i asked him if the car was burning rich or lean. neither, everything's running at the proper level.

i talked to my shop teacher today and he said that the exact same thing happened to a kid a couple years ago and it was just a bad cat. then the kid cut off the cat and ran a straight pipe. but that's just not my cup of tea.

on a side note, it really pisses me off that i waited till now to take a shop class (auto 101). and it's the second semester of my senior year. i was pretty hardcore into computers when i first started high school. so for some reason i wasted my time taking business classes. 6 of them actually. it takes me till half way through junior year to decide there's no way in hell i'm doing any computer stuff for a career. so get this, when i apply this fall for college, i chose a major in psychology. so at the beginning of this year, now that i'm interested in my car, i finally decide to get in some shop classes. i wish i would have been hitting up the shop classes since freshman year. ugh.

 

well i brought it in on wednesday morning. the guy said he couldn't really pinpoint one thing, but the best bet is to replace the #3 injector, which was the original cylinder that was misfiring. the part wasn't supposed to come in today either. i stopped by tonight because i forgot my glasses and the shop was closed. i saw my car was sitting inside with the hood open and the computer hooked up inside the car. so i'm guessing they got it installed, and of course it didn't solve the prolem. we'll find out tomorrow, but i'll but it's still running crap.

 

i was right. new injector did nothing. the only thing left is compression. i called the original place i bought it from, asking for some type of finacial compensation, and of course i get nothing. will have to try with a compression test and see what the warranty company says.

the shop is leaning towards either a broken valve spring (i've heard no loud bangs so i'm doubting this) or a faulty intake gasket.

i'm freaking tired and i just missed two days of school this week and i'm just at a complete loss right now. 3 options as i see it. it's either fixed, sold, or gets a V8 this summer.

 

just from searching some it looks like there's a history of GM having issues with faulty plastic intake manifold gaskets. just emailed them.