92 Camaro, 3.1, I just bought. 127k on it. Have replaced cat, EGR, MAP.... Sometimes it runs smooth and great then usually at a stop itll cough and run very sluggish, like no power, hard shifts, tach bounces all over and it can stall, for the most part it doesnt. Any ideas anyone???

 

if that car is equipped with a TCC solenioid, consider changing it.

 

i had a 3.1 in my grand prix, same syptoms, and my alternator was the problem.

 

Alright, im an idiot here, whats the TCC solenoid??? What does it control?

 

TCC stand for Torque Converter Clutch. The clutch is activated by a solenoid. The clutch is used to lock up the torque converter for better fuel economy. The clutch is supposed to release whenever the brake is applied, and also below a certain speed. If the clutch does not release when comng to a stop the engine will try to stall and the car acts silly. Is the SES lite lighting up when this happens?? Low system voltage will also make the engine run weird.

 

No, the light is not coming on. But sometimes when im stopped at a light, the car kinda does a hick up and everything is fine again. And then the same thing occurs again and its back to being rough.
My gauge says the alt is putn out around 14 maybe even 15 volts. Could that be an issue as well?

 

You could check the IAC Valve, Idle Air Control Valve, located on the intake manifold by the throttle valve. This valve alows air to bypass the throttle plate at idle. Essentialy it's a controlled vacuume leak. This valve can carbon up and start to stick shut, either not opening enough or opening to slow. I can't say for certain that is the problem ,But, I have seen other 3.1's with the exact irratic idle symptoms that you described they did'nt throw codes either. I've cleaned a couple of IACV's on TBI motors(remember the Tech4) so I know that that particular one can carbon up. Not sure about the newer 3.1's but it's a place to look.

 

Ok, thanks. If I unplug that and its working fine, shouldnt the engine have a noticable change?? I have unplugged it and nothing changed at all???

 

sounds like your volts are fine, isnt there a way to unplug the tcc solenoid? this guy i work with said his cutlas (3.1) had the same problem and he disconnected the plug and it was fine, just ate up a little more gas above 70. hope that helps

 

ok, ill try and find that. But i was referring to te IAC, i unplugged that and there wasnt a noticable change in the engine. Is there supposed to be???