My '94 22RE is freshly rebuilt with less than 100 miles. I was failing emissions horribly and throwing a code 21. I replaced the oxygen sensor with a new Denso unit, and now it passes emissions beautifully, but has a very consistent idle.

The idle is usually about 700-750 RPM, but occasionally will sit at 1100 when coming to a light after cruising, and won't drop down without a tap on the throttle. What could be causing this varying idle speed?

 

Bleed the cooling system first then check your tps. If its none of those then make sure your afm is functioning properly. Check out 4crawlers page for the tps check it saved my but last week.

 

Can also be dirt / contamination on the throttle shaft or throttle cable, improper dashpot operation, sticking pedal (under the dash)... any of which could cause the throttle to stick slightly open.

 

Mine gets a sticky idle if I dont keep cleaning the TB out.. must be a bad PCV valve...

Check the TB, TPS and wiring..