i got a 89 iroc z with a 305 tpi i just bought a mass air flow sensor thinkin it was the problem because it was throwing codes... but i was wrong... sometimes it idels high about 15 to 1800 but if you hit the gas real quick it usually idels right back down... i took the throttle body off and cleaned the inside real good... could it be worn out bushings in the throttle body?... any ideas???????????? been rackin my brain for along time on this one so n e help would be good

 

sounds like a worn throttle spring. mine does it too. i just tap the throttle and it comes back down.

 

yeah more or less sometimes if ya push it back to the idel screw its fine