Just picked up an 88 pickup 22re 5 spd 4x4. The truck runs very well but the idle is very high?

 

There is a adjustment screw on the top of the throttle body that will adjust the idle. 750rpm.

 

If it surges jts the water pump dont know why but if you put wrong water pump on it makes engine surge

 

Or at least it does if the impeller blades are different sizes

 

I played with the adjustment a little the idle came down. But after driving the idle is back up again and kind of fluctuates, almost acts like carbureted electric choke. I can kick it down if I hit the throttle sometimes, this problem might have been there before but I couldnt tell because of the high idle, is there an IAC or something similar?

 

There is an IACV that causes higher idle when the engine is cold. They tend to wear out so your rig might idle crazy high when it's really cold outside. Mine idles at 2000-2600 rpm while it's warming up. If the idle is fluctuating while at a stop light (with the brake pedal pressed) then your operating temp idle is still too high, turn it down to 850. Also need to point out that a dirty throttle body will cause erratic idle issues and so will that little O ring on the idle adjustment screw if it's gotten hard and no longer seals properly.


Have fun!

 

Thanks you I will take off and clean the throttle body I can see the oring being worn or dry the screw turns fairly easily