About ready to cry..PLEASE help

**TJs97** · 06-27-2008

OK first things first..I am a girl so I can cry

My 97 GTP is driving me absolutly insane. My car has been throwing the fuel trim lean bank 1 code pretty much since I bought it. It has a rough idle and used to stall out while idleing I have tried replacing everything I can think of and now I am at a loss. The following have been changed

- MAF sensor
- plugs/wires
- fuel filter
- front 02
- multiple vacum leaks fixed
- injectors checked
- TB cleaned
- smoke tested for any missed vacum leaks
- fuel pressure tested
- compression tested
- battery/alternator wires/connections are all OK
- new battery (not really lean related..but the battery test failed even though the battery That was in the car was fairly new)
- alternator was changed when I first got it

Is there something I am missing?

**VinnieGTP** · 06-27-2008

Did you do the LIM gaskets yet? You can soak the engine in brake cleaner while scanning the front O2 and watch for it to stay near .999 for over a second or so, then you found your leak. Dont forget where the EGR bolts to the LIM.

**TJs97** · 06-27-2008

i have no access to a scanner Ive asked over @ CGP but no one can help. The above has costed me well over 600 bucks to do and Im scared to find out how much the LIM will cost

**VinnieGTP** · 06-28-2008

If you have that massive a vac leak, when you reset your PCM and start the car it should run like crap while it's relearning the fuel trims. It will give you plenty of time to soak everything down with brake cleaner until the idle settles down. Then you found the leak without a scanner.

To reset the PCM unhook the battery for 20 or so minutes.

**QwikGT** · 07-04-2008

where are you in NJ? im on staten island i can do the LIM's if you want just supply the materials, and some food! if you want i can try to troubleshoot it for you

**Zef_66** · 07-07-2008

I would look into a cracked exhaust manifold or EGR tube.

**GTPJOE90** · 07-08-2008

i hope you get er fixed chicka!

**TJs97** · 07-09-2008

Thanks guys.. I (once again) dropped my car off to a 5th mechanic who also can not find anything. Luckily..this one didnt charge me. He drove it around for about 50 miles w/a scanner and all the readings are fine except my temp gauge is not accurate. So I am totally at a loss.

If it were the exhuast manifolds wouldn't I hear that all of the time? I know that a CAT would probably throw its own code but should I consider that? If there was a problem w/the exhaust..would that show up on a scanner? ( I believe it was autotap w/gm enhancments)

I am live in Sussex County NJ but spend most of my time in Bergen. I'd be happy to make anyone dinner who made the trip out. In fact..my Dad is away almost every weekend and my uncle owns a gas station right next door. Maybe I'll talk to him and see if I can hold a mini mod day.

**boredout** · 07-09-2008

it might be a sticky injector or clogged fuel rail for bank 1 side the pressure could be good al the way to the needle valve but clogged in between some where or maybe something electrical.it could be sendin half ass current to bank 1 side injectors take a electrical tester an check bank 2 an 1 an compare the 2

**Zef_66** · 07-09-2008

A cracked exhaust manifold would not make a noise all the time. When I installed my PEMs, I realized my old front manifold was cracked. I never heard a noise. But it did run better afterwards.

**QwikGT** · 07-09-2008

im about a half hour from bergen county so i dont see a trip being a problem. mod day sounds nice post what u wanna do sweetheart

**TJs97** · 09-07-2008

up..still not running right

TDCRacing · 09-07-2008

Well first off let me explain how the o2's work. You have an O2 sensor that reads both banks of the engine. The front 3 cylinders wich are 135 and the rear 3 wich are 246. So when you get a code for Lean bank one or something to that extent there is no way to tell wich ''side'' of the engine is actually running lean. For example if you have a bad injector on the back of the engine it is going to throw a code for lean bank one.Got me?

With that being said....I have a cupple questions.You have to know some kind of history on the car before you can start to diagonoise somthing that is wrong.

How Did you test the injectors?
What was the fuel pressure actually at at idle?

Describe more about the problems you are having as far as driveability goes.

Is the problem only at idle?
Does the car run rough under heavy acceleration?
Does it happen all the time?
If not how long?
Is there anything you can do to make it stop? Give it gas ect?
How many miles does the Fuel injectors have?
You said the car has always had the lean bank one code? Did the problem your having now always exist also?
What was done to the car around when the problem started?
And what mods do you have on the car?

Not to put you through any more headach or anything but with drivability problems along with idle i'd have to say that it is an injector if the fuel pressure is where it's suppose to be at and other factors are met. It's just about the only logical thing that can actually reduce fuel after the fuel rails if the pressure is good. But lets do a little more thinking.

Ill be here till you fix the problem. I know that these things are a pita but you got to think them through. Just because you have a cel for something doesent always mean thats what the problem actually is.

And I know you may not have all the Knowledge and tools as others but well get through it and get it solved. So lets see what ya got.

**Blown97** · 09-07-2008

Your symptoms sound like an intake leak. Did you spray TB cleaner on and around the EGR tube yet? Another way to find it is to get some vacuum caps and go through the vacuum manifold on top of the S/C, take off the vacuum lines one at a time and replace them with the cap. If there is no change pull the cap off and put the line back on again, continue until you have checked them all.

Let us know how it goes.

TDCRacing · 09-07-2008

That would have to be one hell of an intake leak to cause issues like that. Now as far as the fuel trims it doesent take much for them to go to -16. If it was that it would have to be huge wich means anybody with a set of ears could probably hear it.

I can unplug the vac line off of my car straight off the lim intake and there are barley any changes in idle...just idles a tad higher is all...and of coarse the trimms are out of wack

**Blown97** · 09-08-2008

Originally Posted by TDCRacing

That would have to be one hell of an intake leak to cause issues like that. Now as far as the fuel trims it doesent take much for them to go to -16 (In her other post she says, "The long term fuel trim is pegged at 16.4"). If it was that it would have to be huge wich means anybody with a set of ears could probably hear it.

You would think you could hear it but when this happened on mine there was not the usual vacuum leak hissing sound. I kept tuning my LTFTs and they kept staying + no mater what; and then one day they pegged to +14 - +16 that's when i knew i had a problem and needed to find it. Turned out to be the EGR tube. It cracked about 1/2 way around the tube where it met the intake manifold. They don't always crack like mine did, some can be cracked worse some not as bad. Either way if it is cracked it is bad and needs to be replaced.

I can unplug the vac line off of my car straight off the lim intake and there are barley any changes in idle...just idles a tad higher is all...and of coarse the trimms are out of wack

Like you said, it doesn't take much to get fuel trims out of wack. At the same time it is possible for your system to account and adjust for smaller vacuum leaks. Your system will have quite a bit of a hard time adjusting for a larger vacuum leak.....IF it will run at all.

The only thing that is interesting to me is she had the engine "smoke tested." If so a cracked EGR tube would have showed up then.

Keep us informed and let us know how its going and/or what it was.

TDCRacing · 09-08-2008

Originally Posted by Blown97

The only thing that is interesting to me is she had the engine "smoke tested."

True

**gptuner** · 01-23-2013

If you're still having this issue you can send me a message, i run a 3800 specialist shop called S&S Performance in central NJ you can always arrange to drop it off or stop by to have me take a look at it, i don't charge for trouble shooting either

Also, if your MAS Screen is damaged, bent, notched slightly or its been removed all together it will throw this system too lean code and cause a rough idle as well just to help point out the less obvious things to check