My 305 TBI (auto) idles at almost 1500rpm (in park) anyone ever have a similar problem and might know the cause (and how to fix)?

thanks

 

Vacume leak? Check vacume lines make sure they are not leakig. Do some sprayin of carb cleaner all arround the intake and tbi, not in it, and see if the idle changes. if not your in the same boat I am, the IAC.

 

Thanks- I''l check that. What's IAC?

 

It's the idle air control valve that helps regulate the a/f

 

one time I broke the harness on the IAC pulling the valve covers, and that caused the high idle. If thats messed up that will make it as high as 1500 like you said.

Its on the passenger side back corner of the TB and have a sqaure plug with 4 wires on it. Inside it looks like a metal plunger.

 

Check your CTS (Coolant tempurature sensor). The one fer the ECM, its on the front/top of the intake manifold. its only a couple of bucks, so maybe just replace it. That its how my car acted when mine went - although it threw a code (15 i think)...