I have a 96 D1. Its finally running good except for one last issue. I have a little bit of a high idle issue. When I am driving around the truck will not idle down lower than 1350-1500 rpm unless I come to a complete stop (say at a light) then after sitting still for about 5-8 seconds the idle will drop to 750 rpm. I can put my truck in gear and give it some gas and watch as it will slowly speed up to around 30-35 mph without my foot on the gas. Anyone have any ideas? I have new plugs, wires, injectors, valve job, head gaskets, clean throtle body and stepper motor.
Thanks,
Jason

 

Did you also clean the port that the stepper motor goes into?
Did you move the stepper motor plunger at all?
Is your throttle position sensor tight?
Is everything plugged in?

 

With my 98 D1 I cleaned the stepper motor and the intake hole area, then replaced it and it worked for awhile then I had to finally replace the motor then after a couple of years i had to replace both the stepper motor and then the TPS

 

I cleaned inside the stepper port. I didnt mess with the plunger. Can I try to swap it out with a replacement for a Jeep Cherokee? Do you have to have it calibrated by a dealer when you put this part on or do it adjust automaticaly?

 

Yes you and try the one from a Jeep 4.0, whether or not it needs to be calibrated is a crap shoot.

 

usually it's the stepper motor. can be throttle position sensor. got to check to voltage. or the throttle linkage could simply be stuck. make sure it's sitting right. clean your throttle body really well with carb cleaner. i had the same problem with mine for a while. i just went through the list and figured it out. doesn't sound like a vacuum leak though.