(also posted in ECM board, just hopeing for more answers.)

90 camaro RS 3.1 liter. rough idle always, can't idle when cold, (it just dies) no trouble codes are being thrown, I had a chevy dealership check it out, they ran diagnostics on it and found nothing wrong with any sensors, they say electically its in good standing, But the problems im experience appear to be caused by a bad sensor. any suggestions on what to check? no matter how crazy they may sound? know of anyone with the same problem, and how they delt with it? (the problem improves greatly when TPS is unplugged) but the mechanics say theres nothing wrong with it. is it possible the ECM just went stupid on me? any pointers would be greatly appreciated

 

Try a new ignition module - located inside the distributor under the rotor button.

 

Would also make sure all of your ignition system is in good shape. (plugs wires cap rotor coil)

 

Could be any number of things. Sounds like a vacuum leak to me, or possibly a weak coil.

 

Knock sensor? IAC Valve? I don't know, my car is being weird now that it's getting cold too, so I hope someone knows.

 

replaced all my vacum lines, they were worn out. everything about the ingnition system is new, I just did a major rebuild on the engine. (new block, pistons, rotating assembly, heads all new) had a cracked block and heads from over heating. so yeah new distributer, ignition module, plugs, wires. all new. I think i figured something out though, i played around with the IAC valve. moving it in and out. and the idle has become much much more smooth. but it will still randomly die on me while coasting or idleing in gear. I think it may just need a new, IAC valve, along with proper adjustments. Ill let you guys know how it goes.

 

Yeah I would like to know how that goes. My car idles alright when in park and neutral but sometimes it sounds like it'll trip a little bit every few seconds. Worse when it's in gear and I'm at a stop.