Question:

I 89 chev trk. idles to fast at times,if you turn off.start up agian. most the time it idles ok.??

Answers:

A-Best: your choke is getting stuck spray it down with a little pb blaster  

A: buy a can of carb cleaner and clean the butter fly it could have carbon build up my buddies truck was doing that and after cleaning the carb its fine again.if that doesnt work could be the idle motor is going bad.