I have an '89 IROC (305 TPI) with a couple idling problems. It's bone stock except for K&N filter and Flowmaster cat-back. The fuel pump/filter is new, injectors cleaned recently, just tuned up with plugs, wires, cap/rotor, timing checked, etc. at local shop. After the tune up it starts and generally runs better, except I still have a couple idle problems that've cropped recently (and no check engine light).
- Sometimes, but not always... idle seems WAY too high when started cold and won't back down even after running for some time and warmed up. This doesn't always happen.
- When warmed up, in drive and stopped (eg. at stop light) the rpm starts getting a bit erratic and engine starts missing to the point where I'm afraid it's going to stall out. It does a very odd 'lurching' that I've never felt in a car before. Putting it in park helps a bit, but still misses pretty bad.
Thanks in advance.