Had optispark surgery last August, but only put about 5k on the car since then - only 69K total. I had a local garage do the opti, ran ok for a while but hasn't been the same since, most noticable is the idle...sometimes when I start it will idle at 500. sometimes 1200, rarely in between or normal (750). Doesn't seem to be related to operating temp, stays the same until you turn it off & re-start.
My manual says it could be vaccum leak or dirty injectors, I don't believe it's either; does this sound familiar to anyone - any good place for me to start?
I can tell you that before the opti was redone it ran perfectly...except that it would cut out once in heated up sufficently, usually going 75 on the highway.

 

Try spraying carb cleaner around the engine bay and see if that changes anything, that will let you know if you have a vaccum leak, then try some fuel injector cleaner, it's only a couple bucks. Then pull out your IAC valve and clean it off, maybe replace it if it looks bad. Thats only a few things, but maybe it will fix your problem.

 

I second what he said: IAT valve and vaccum leaks is where I'd start.

 

Thanks, I'm betting you're right about the IAC - is it easy to get at?

 

It's on the side of the throttle body, but it's a little tough to get at. Your best bet is to just unbolt the TB and it's a snap to get to.

 

oh yeah, it's right on the intake.