I just bought a 1990 Cherokee 4x4 and its my first. Ive never had a 4x4 so its all new to me. Ive been trying to find a quick run down of the different 4x4. Part time, full time, Hi and Lo. Just basically the conditions of road/surface to the selection.

Anyway the real reason. I have the High Idle problem and have a quick question.

On 90' 4.0 is there and Idle Adjust Screw. If so is it covered by a metal thing in the middle of the throttle bodie, and how would i go about getting that out.

 

sounds like you might want to check your Throttle positioning sensor and clean your Idle Air Controller.

 

dont know about yours but my cherokee has a sticker on the sun visor advising what road conditions to use 4x4 4x2 is rear only any road 4x4 hi part time is loose surface only 4x4hi full time any surface 4x4 low loose surface only

 

Adjusted TPS to specs from another thread and idle speed seems fine. I have massive vaccum leeks to track down but Im happy with my 600 dollar toy.

Is there an easy way to tell for sure if 4x4 is engauging. I dont want to go by the lights. On the dash because the fuse box at one time had a fuse burn out so Im not sure what really works

 

Get on some sand and have a friend get out and watch. Put it in 4x4 and floor it. See if all 4 tires spin. Thats how we used to do it back in Alabama

 

Put it in 4 low on pavement. You'll feel it. Turn the wheel to lock and try an turn. You'll know lol.

 

just put your foot on the brake, engage 4low let off the brake. you will feel it jump a lot more than if in 2wd. easiest way to tell