My girlfriends mom has a 92 C5 that idles real rough. pings and seems to be missing. We've changed the plugs (that were nasty), the TPS, the O2 sensors and recently the ECU was replaced. I don't know what else to check. Someone please help.

 

try doing an idle relearn here is how you do it...
Turn the key on but don't star the engine. Remove the number 16 & 23 fuses from the underhood fuse box. Turn the key off. Replace the number 16 & 23 fuses. Start the car and let it run @ 175 degrees or warmer for 5 minutes. Shut down the engine for at least 30 seconds, then drive the car for about 30 miles at varying speeds. If you do this kind of low bugget mods you will feel a big difference in the seat of your pants, and ET's

 

I tried just resetting the ECU by diconnecting the battery for about 30 mins then reconnecting it and letting the car idle for about 10 mins. Helped a little bit cause the car was running rich but didn't get rid of the pinging and rough idle. Any other ideas?

 

Mopar, what kind of car is it??? No such thing as a 92 C5. Is it a 92 or a C5??? If it is a C5, you should check for codes. If it is running that poorly, it will show up on the computer.

 

Oh heh ok. It's a 92. Sorry as you can tell I'm a Mopar guy. Wouldn't the check engine light be popping up if it was bringing up codes?

 

ask someone on corvetteforum.com goto the C4 section