incorrect operation of choke choke not shutting off after warm up
The Idle Air Control valve located in the throttle body.
It may be in need of a good tune up.
Its in your owner's manual. My 1998 runs about 40 PSI on Highway and 30 PSI at idle. Goes down a little when warmed up. Was a little stronger when new.
A car may idle up and down due to "Improper fuel mixture". (The fuel in the car may consist of an un-even balance of air or gas). However, there are a few other ways a car can idle up and down.
If both vehicles have the same motor it should match up. You may have to order or make an adapter for the wiring.
idle speed controll or tps throttle sensor
Check/ replace the TPS if the idle is up and down.
When my '97 Dakota did that, I ended up replacing the idle air control valve. That cured it .................
I a 97 pick up and the power steering pully is pressed on and pressed off
The IAC (idle air control) at the throttle body is usually the problem.
20 psi at idle up to 75 psi at 3000 rpm