2.9L Idle Speed Problem!!!!

[boxfan889]

Hey, i have an 88 2.9L ranger, and when i am stopped whether it be drive or park, it begins to have idle issues, it goes from about 800 to 1000 rpm's and it just fluctuates constantly, it is a rebuilt motor, and i am just totally stumped with this problem, i was wondering if anyone can help?

 

[87Ranger4me]

My 87 did the same thing till I replaced the engine coolant sensor.

 

[bro2]

this probably a dirty or bad isc motor (idle speed control ) it is located on the intake just behind the throttle body. there are two air holes in the opening of the throttle ,spray the holes with carb cleaner with the engine running.spray slowly so the engine doesn't stall. If this doesn't fix the problem you will need to replace the isc motor. Clean the throttle body with carb clean while you are messing with it.

 

[boxfan889]

I had cleaned them and bought a new isc, it still doesnt fix the problem it seems it is running really rich too. I was thinking maybe a vacuum issue?

 

[robo]

clean the throttle body and idle air control motor and it should go away