Hey everyone, i just bought an 87 Camaro 2.8L V6 that didn't run well from the start. So when I start the car it starts up and idles normal but after 2-3 minutes the rpms increase. Not sure to what rpms it increases to but it continues to stay at high levels and does not come down or it will take a bit for them to come down. Some times when i start it up, it would be very rough, sometimes a knocking sound and engine will shake and die off. Another time I would try to rev the car after a start up but when i rev it the rpms don't come down to normal idle level,it stays reving for like 15 -30 seconds. btw what would be the normal idle level,? And isn't the rpms suppose to be higher at cold start and then come down to a normal idle? I don't have a tach gauge either lol so its hard to tell. The car also has a check engine light with codes 22 and 34. I replace my throttle body sensor from a camaro at a junk yard, still no luck. Could it be electrical? I was also told that the car took alot of gas the last time it ran a few years ago. How can I fix this problem? Any help would be appreciated. Thanks in advance.

 

check for play in throttle shafts, clean/replace IAC then do IAC reset. check for vacuum leaks.

 

Connect a scan tool, look at the data stream for clues.

What is the commanded idle speed? What is the actual idle speed? What is the IAC position, and does it change?

Yes, a cold engine would normally idle faster than a warm one.