I've noticed something odd. Sometimes my idle increases after I've been driving for 20-30 minutes. Throttle bodies are clean, no vacuum leaks that I've been able to find after thoroughly checking. Idle is elevated on start by the aav and, once at operating temperature, drops to 600 and for is stable there. Then sometimes I pull up to a stop and I notice it is 900. At a later stop it will settle at 600 again. No obvious triggers or pattern I notice.

I've tried to puzzle this one out and I can't think of anything that would cause this.

Throttles are smooth acting without any signs of binding and are clean inside. Set to spec.

 

Possibilities:
ATF / TC drag?
Throttle body seals not perfect?
AAV action not perfect?
FPR inconsistent?
Coil/plugs/HT leads/Dizzy not perfect?
Fuel temp not stable?
Greg

 

hmm throttle seals have not been replaced. Anyone have a source? I can't find them in a sea of linkage bushings.

Could the aav aav even possibly reopen? I don't see how.

New single coil. New NGK plugs. New Taylor leads. Dizzy rotor, cap new, pickup gap set.

New bosch FPR.

Vac fuel temp switch. Tested working. Switch temp not measured. I suppose it could be enrichment. That would make sense and would be in the right RPM increase range.

Thanks for the ideas!