High Idle Problem

[craigster]

Lately my 88fj62 has been idling at 700-800 when cold but after driving around for 30 min. the idle jumps to 1500-1700. I'm going to be working on it this weekend and was wondering if anyone has any experience with this problem so I can pick up a part if needed while I'm picking up a water pump and fan clutch. Thanks, Craig

 

[overhanger]

Craig,
Two initial things to check: make certain that your manual throttle is fully pushed in for one. The other would be to see if you have any control of idle speed adjustment by turning the golden screw on the front of the throttle body clockwise to lower the idle speed. Ordinarily, you should see cold idle speeds around 1000 rpm until water temp starts to creep up to normal and then down to 650 rpm when it reaches normal temp. Any recent maintenace procedures been done that could have affected idle? A vacuum leak will cause abnormally high idle speeds.
Steve