I have a 02 Camaro SS, i have a TSP MS4 cam, stock heads. I started having problems with my car about a week ago. WhenI come to a stop light, car begins to idle, then shuts off. It seems like it starts to struggle to stay on. Hooked it up to OBDII computer, it read meaages about my two O2 senosrs being bad. They were having low volt readings and a lean air fuel mixture. After changing my O2 sensors, it still does the same thing, however it does run a little better. It still does shut off at idle on road, but not as often. A friend said he thought it was my TSP and IAC (Idle Air Control). He said the computer was reaeding my TSP was low, it was going all the way down to 0%, and it should not be doing that. He said that the IAC my be needing to be adjusted, if it is bad, it is giving a bad reading to the TSP and shutting the car off at idle.

What do you guys think it may need? What other things could be causing this problem?

 

Has anyone here used LS1 Edit? Any pros / cons?

 

I would recommend HP Tuners or EFI Live over LS1 Edit as they are more user friendly. I use HP tuners and like it alot.

TPS(not TSP) = Throttle Position Sensor
The throttle position sensor uses a 0-5 volt signal to tell the PCM how much throttle is being applied. It is normal for it to read zero when you are not pushing the accelerator.

IAC = Idle Air Control valve
The PCM opens and closes the IAC to achieve the desired airflow for the car to idle at the preset RPM. With the car in park and the AC off you want to see an IAC count of 30 or lower. If it's any higher than this it can be maxing out at times and causing surging/poor idle quality. You can either drill a larger hole in the throttle blade(a little larger each time) or adjust the setscrew on the throttle stop to open the blade further when it is at rest(closed) to achieve the desired IAC position.

I suggest a fresh set of plugs because if you were running bad O2's there's a good chance the plugs are fouled also.

What is your idle speed currently set at? Have you had a good tune done after the cam swap?

 

Right now its set at 850 idle. I do know that i'm runing lean. I just need to retune. Where did you get HP Tuners? How much $$ ?
My car hasn't been tuned since I've owned it. I bought it 2 years ago, since then it spent about 10 months in storage. However when I got it out (came back from Iraq), it worked just fine. This problem just started not to long ago, about 3 weeks now. Sometimes at accelartion it has some lag. Would that be the plugs? I bought some NGK plugs, just trying to make the time to change them. What plugs do you recomend? Also what size plug gapping is recomended for these LS1s? I'm currently runing .45

 

I bought my tuning software directly from HP tuners about five years ago. I think it goes for around 500 bucks now, but I'm not positive. If your car was running good before then it's most likely not tune related. If it sat for 10 months without running it may have clogged/dirty fuel injectors. Replace the fuel filter and run a good fuel injector cleaner(just don't buy the cheapest one) with your next tank of gas. For your setup you can run TR55 or TR6 plugs, leaning more toward the TR6. Common gaps are 0.055 for TR55 and 0.045 for the TR6.

 

You know I ran an Injector Cleaner, the week before this started. I already had the engine light on, then it turned off the day I ran the injector cleaner. But it came back on about 6 days later. So you think that may have something to do with it?
I'll see about replacing the fuel filter still.

 

my check list.
1. Clean TPS and IAC
2. Check for leaks on intake, vaccum and injectors
3. Replace spark plugs
4. Check / Replace fuel filter.

Any more options you guys can think of?

 

Before you do any of that I would do a simple idle relearn now that you have new 02 sensors. Reset the PCM, then start the car cold - don't touch the gas or brake, let it idle for 10 minutes then shut it off, wait 15 seconds, then restart it and see what you have.

 

In my opinion

first off if your car WAS running fine and now its not, its NOT the tune , tunes dont change.

second, i would clean the MAF (mass air flow meter) and i dont mean just shoot it a little with some maf cleaner, i mean use a whole can on those little resistors until the front of them looks like the back. but dont damage them by touching them.

the maf bieng clean makes ALL the differance in the world.

 

just curious but

how long has the car been running and did you have your pistons fly cut? if im not mistaken an ms4 is a pretty big cam for a stock motor with no fly cutting and you could have some PTV (piston to valve) clearance issues. i could be wrong though maybe sombody with more knowledge on that cam will chime in.

 

I'll try that! Thanks DaddySS N Plague.

And as far as I know, it has the stock pistons. I bought the car the way it is about two years ago. Just now it started giving me problems. Previous owner said that all he had to change was valvetrain (i.e. valves, push rods, springs, rockers). I already started chaning the spark plugs, took the IAC out, cleaned it, sprayed the MAF a little. Checked the TPS, it looks good, no problem. Cleaned the IAC chamber, sprayed with carb cleaner, it had some carbon build up. Looks like my car is runing a little too lean. My plugs were looking white. Either way, I want to retune it so it runs better.

I'm starting to lean, that it may be the MAF, I looked at my Air Lid and the seal was not sealing well. So it may be that the MAF is dirty or damaged. Should the MAF give me an engine code?

 

A scan tool like TECH II or Snap On can read MAF values and tell you if they are in the normal range.

If you know anybody else running a stock MAF see if they will pull it and let you run it to see if it cures your problem.

 

i have the same issue and i don't know how to fix it

 

Well I tried, changing spark plugs, cleaning MAF, TPS and IAC but no fix yet. I am about to swap MAF with my frineds 2000 T/A, we'll see fi thats the problem. IF that doesn't work I will have two options left. I think it maybe my programming or my fuel pump/filter. I'll post the results.

 

PontiacSLP what exactly does yours do? What have you done so far to fix it?

 

its same as your problem it dies at idle , i changed the plugs and TPS and it still till now , i went to the tunner and he did't know wow to solve the prob

 

Well SOMEbitch, I swaped the MAF with another OEM, and it still did the same thing.

So I have another question, will running your car LEAN, hurt the car on the long run? I know my car is running lean, it has been since I've had it.

Also, after changing my O2's, why would it still give me that same codes. And yes, I did reset the engine light after changing them.

 

I had a similar problem. Check fuel pressure at rail and if it moves any off 58 u either have a clogged filter or sock on the pump or a bad pump itself. Hope this helps

 

Hey guys my 2 cents.I have had the same problem.I cleaned everything.Even ran 2 BG Decarb kits through the engine.And Finally determined it was the damn gas I was getting.I changed gas stations to a better known fuel.No problems since.That would be my suggestion.Try some different fuel.

 

What codes are you getting from the O2 sensors? If it's the heater codes then it's a common problem when installing long tube headers. It moves the sensors so far downstream that they take longer to heat up and it sets the DTC. I usually disable these codes in the tune of any car I put headers on. If it's insufficient activity codes or others pertaining to actual sensor performance then you may need some new O2 extension harnesses. It would also be a good idea to check all harness ground locations to eliminate them as the culprit.