I just put a new idle air control valve on the truck this morning and hooked everything back up, but now when I push the clutch in the rpms drop to like 400 and when it’s just sitting idle without the clutch pushed in it idles just fine.

 

Adjusted the tps and rechecked all the vacuum lines and everything is set like it should be, but whenever I come to a stop the rpms drop to about 400 for a few seconds then they jump back up to normal. Any ideas or tips would be appreciated. Thanks!

 

What was it doing before you put on the new idle air control valve? Which IACV did you install?

Standard Motor Products AC141 is actually the same as the Toyota part, and it's made in Japan too. AC141 is what I installed on my 92 pickup with 22RE, and it fixed my random high idle problems.

The IACV is coolant sensitive, so make sure your coolant level is full, and there are no air pockets.

 

Sounds like a vacuum leak or brake booster. What method did you use to check for leaks?

 

Does this problem only happen with the clutch pushed in?

What happens when you just step on the brakes?