Random engine kills

[2Fast4U]

Hello all,

It's been about 5 years since I was in the SHO game and I guess I may be back in for a while. A friend of mine just finished a near complete rebuild of my 1995 SHO. The engine is extensively modified and I'm having issues with the engine stalling randomly at idle (sometimes several times consecutively when at stop lights, etc.) and also seldomly when at freeway speeds. I'm assuming this may have to do with the old LPM chip? I was considering purchasing a tweecer but I know absolutely nothing about tuning and it seems that the tweecer is not for newbs like myself. I'm hoping that someone might have a suggestion as to what I can do to fix this issue. Any thoughts would be greatly appreciated!

 

[SHOdded]

:wave: Could be anything at this point. We don't even know if the SHO is an ATX/MTX! So if you could give us details about your car/PCM/LPM as it stands now, that would be helpful.

If it is possible, pulling codes is the first thing to do. Check your grounds, dump any old fuel, clean out fuel injectors, etc. are all very "normal" todo items in cases like this.

 

[2Fast4U]

Ok, where do I start with this build... It is probably the only converted ATX-MTX in existence. The engine itself has 40k miles on rebuild; 3.2l, stage II cams, BBB, extrude honed intake + runners, 80 MAF, underdrive pulleys. Did I forget anything? The LPM came with the original owner who built the engine so I have very little info on the details. The engine was originally in a '91 MTX but I don't like that gen body style so I transferred it into a '95 ATX and had the ATX converted. Does this information help?

 

[jayro]

What is your idle set at? Does it have a lightened flywheel as well? When you say "At highway Speeds" do you mean while in gear and going or when you push in the clutch?

With stage 2 cams and a lightened rotating assembly (UDP and/or flywheel) it is possible that it is not able to catch and hold the stock idle when the rpms are dropping quickly. I had this in mine and decided to just raise the idle via my LPM. I was also told that the ECU will learn to compensate for this over time, but then would have to relearn every time it was reset. Too bad because I REALLY liked the way mine sounded at stock idle.

 

[2Fast4U]

Yes, it has a lightened flywheel and the engine will stall while in gear but mostly when I've pushed the clutch and am idling at stop lights. How do you raise the idle via LPM? I'm a newb with tuning.