Idle issues

[stangant]

When I first bought the car it idled a little high and then when down from say 1500 rpm to say 800 rpm's, now it stays at 12-1500 more often and has a strange sound idle but rpm's are not changing... Is this the IACV? If so how is the repair on this?

[mitmaks]

could be a few things, vacuum leak, IAC valve, dirty throttle body, TPS sensor

[stangant]

I checked for the vacuum leak and didn't find anything. I took the intake off and it didn't look dirty. I will check on the TPS connection and the IACV.

[davmac]

So when "new" idle started at 1500 - 1800 when cold and eventually settled to 800 rpm?
Warm idle spec is a little lower, but if idle is steady then when you got the car I'd say it was set up Ok.

If the car is not idling high (not surging) then I would follow procedure to set idle as when doing tune up. Do check that it isn't something as silly as the throttle stop screw (at the linkage - follow the cable) holding the throttle open. Also confirm coolant is full. If coolant is low - or not flowing through the little hoses at the bottom of the throttle body (idle air control valve) you get continuous higher cold engine idle speed. Normally though if there is air in coolant system then the idle will slowly surge up and down.

Use online manuals to 1. set timing 2. set tps closed position 3. set idle speed. Instruction in section F2.