idles too fast

[MCFetty]

I have a 98 Ranger 3.0 with a little over 100k on it. It has a high idle condition (around 1250 rpm). I replaced the plenum, throttle body and egr valve gaskets and in the process, five vacuum hoses and cleaned the throttle body thoroughly while I had it off. I have a pcv valve & grommet for it that I am going to install tonight. It runs smoother after all this, but still idles too fast. If I unplug the iac, it settles down to about 750 rpm. I replaced the iac and still have the same result. Any ideas would be greatly appreciated.

 

[Dirtman]

When you unplug the iac valve the engine should almost stall out or idle below 500. You still have a vacuum leak somewhere.

 

[G8orFord]

^^I agree with @Dirtman.

 

[MCFetty]

Any idea how to find it or where to look? Thanks for the info.

 

[Dirtman]

Youtube "how to find a vacuum leak" there are several methods. I prefer using a diy smoke machine (cost about 10 bucks to make). You can also very carefully spray starting fluid around any suspect areas and listen for the engine to rev slightly when the starting fluid gets sucked into the leak. Then theres the old school method of physically inspecting every hose, connection and gasket.