sehoublackss

Took the car in this morning for misfiring badly at idle. It drives fine if you give it gas.

Before I took it in I tried: FI flush, spark plug change and re gap twice, added coolant to the aftercooler (bleed it), and throttlebody cleaner. Nothing helped.

My mods are in my VB garage.

I'll post the results as it comes in.

Manager called back.

Number 2 Cylinder is misfiring.

They switched around coils and plugs to determine this.

They found the TSB about the injectors. (non 2.0L) no help :/

Manager called back.

Stage 2 has a warranty of 12 months... and I'm out of that warranty. Is this BS?

Doc

double check the gap on the plugs as well

BLAZIN07SS

iTrader: (7)

did you install it yourself or did the dealer install it? if the dealer installed it, im pretty sure it goes along with your powertrain warranty. if you installed it yourself then it only has a 12 month parts warranty

sehoublackss

GM installed it, but service rep claimed it (the injectors) isn't covered on powertrain.

***Update***
Problem: Misfire on cylinder 2, running lean on that cylinder. They swaped coils and spark plugs. Same cylinder

I took it back home.

They looked at it all day. For free. Good. No answers. Two opinions.

Tech: Probably a software issue causing misfire problems.

Service rep: Most likely bad injectors, can't say for sure unless I want to tear down the engine.

Options:

1. Take it into the the dealer which installed my GM ST2 and have them flash it with the latest build.

2. Have GM tear down the engine till they find the problem.

3. Hope its the injectors, buy 60lb (to prepare for the TVS) and a 2.8, install and dyno tune.

eurochevy

ya mine was installed in feb or something like that and they replaceing stage 2 injectors..GM Engineering ok'd the warranty for my injectors...i have no idea if thats gonna fix the prob ..prob no because i was like this since stock and before stage 2 ...they've changed a bunch of stuff on teh injectors and changed plugs twice and also all the coils..i'll let u know what happens after i get the new injectors..bu tmy problem is exaclty like urs only i have a loud noise coming from the engine too like a click/ knock sorta thing

sehoublackss

Yeah, my warranty is over 42k miles. If its my injector... screw the GM ones. But let me know.

I'm gonna see if this reflash does anything for me.

eurochevy

kk let me know if the reflahs works for you too cause maybe it would work for me haha..im also considering maybe possible screwed up engine managment comp

Coblasts

I thought the tech 2 came up with which cylinder is misfiring.
They would be switching parts around to determine what it is thats causing it this is a quick and reliable way of trouble shooting which part it is thats causing the problem.
But dont over look a bad connection(bad connector)visually inspecting the pins and recivers for signs of burning ,pitting or corrosion(green color on them).

sehoublackss

***Update***

The flash seem to work at first when they scanned with the tech 2. It was showing 0 misfires. I saw it with my own eyes. However, when they return the car to me and as soon as I start it up, I can still feel the misfiring with the same intensity.

Options

1. Have them investigate further on my dime?

2. Hope its the injectors, buy 60lb (to prepare for the TVS) and a 2.8, install and dyno tune.

rukkee

iTrader: (3)

Mine has had an idle misfire since day one . It won't throw a code thou and can only be seen on a tech2 graph. Are you guys throwing a code ? I think it's something in the GM tune.

eurochevy

my_bd hooked up hpt on my car today at the track..only at idle # 2 cylinder misfires a lot..it has 905 recorded misfires on cylinder 2...cylinder 3 is a short 100 behind so its still at like 800..and 1 and 4 are both below like 50..told me to try putting the air box back together and take out the aem dryflow..see what it does so i will

1BDAZZSS

I had a problem with my car misfiring in the #2 cylinder and i work at a dealer and we changed the coil and the spark plug and even put a new pcm under warranty. it was still acting up and all of aa sudden my uncle noticed that a connector wasn't plugged in all the the way. its the main harness that supplies power to the coils. check that and it that might be your problem

sehoublackss

Thanks for the suggestion. I looked to where the harness connects to the driver side of the engine. However, nothing was unpluged. I'm gonna go back to stock spark tomorrow, but its hell trying to find them around town. The only dealer that had them was closed this weekend.

sehoublackss

lol, go through the trouble to find stock spark plugs since no one except one place in all of Houston carries them, only to strip the valve cover bolts something is seriously against me

I guess i'll just wait to see what happens with yours euro.

eurochevy

ya they still waiting on my stage 2 injectors to come in at the dealer..i put the air-box back together and put the stock filter back in....so far all i notice in a diff is that the whine is almost gone unless i get to higher rpm..i'll keep you posted

Maverick

Guys.... I am having the SAME EXACT PROBLEM. Car drives ok, but when it comes to a stop it tries to stall every single time. I also have stage 2. I'm about to take my car to a tune shop (tune time performance) but I'd like to see how you guys make out. I'd love to save the $450 it'll take me to have it custom tuned.

I have a feeling they didn't flash my car right. Please keep us updated!!!!

sehoublackss

I went back to brand new stock plugs, from the ngk bkr7es I put in a couple weeks ago. Still having the rough idle problem.

I had that stall problem, but I haven't noticed it lately since I did the following:

fuel injector flush, throttlebody cleaned, GM flash update, new plugs. It was probably the GM update the finallized it.

Still have the rough idle like I said.

Next thing I'm going to try is to change the fuel filter. This probably won't help either, but consider it as maintenance.

After that, if the news from euro is what they suspect, I'm going to get 60#, a 2.8 inch, drop those ngks back in, and get a tune.

eurochevy

k so *** update ***!.......got my car back yesterday after they installed the 2nd set of stage 2 injectors..car still runs rough at idle..if any thing it made it worse..back i go!

sehoublackss

woah, this is perplexing

Sloco Productions

iTrader: (2)

have u guys checked ur maf sensor...try cleaning it or getting a new one...i had a really bad misfire in my 2.2 so i sprayed the maf sensor down with sum electronics cleaner and the misfire went away...just a thought

rukkee

iTrader: (3)

I cleaned my Mass air sensor , changed the fuel filter, replaced the cat , removed the stage injectors and checked the boots and o rings , cleaned the throttle body , changed plugs , changed cai back to stock airbox and filter , and have run a **** load of injector cleaner threw it . Still misfires at idle.

It never throws a code , but i can see it on a tech 2 . Car runs fine, doesn't miss underload , and has never stalled . It just bugs the **** out of me to know that has a problem .

Sloco Productions

iTrader: (2)

u need sum1 to check ur **** via HP tuners...see what ur computers doin to mess up ur engine

Coblasts

I looked at your mods,and you have the mounts done.

Correction found the other post and it is the Knock sensor that is affected by the mounts.


Ignore the previous post

stonny9

I wonder if there is a better crank sensor that we can use? I know for the ls1 they can use the lt4 sensor and many do because it is better and less sensative.

my car sounds like this at idle both when stock and with intake/h/dp

Maverick

eurochevy or sehoublackss any updates???

Thanks!