idle problem??

[bert296]

i have a 93 ranger 4.0 4x4 it idles between 2000rpm and 2500rpm why is this what could cause this to happen? im stumped ive tried everything but turning the idle screw back.. any help or input would be great thanks

 

[trail B2]

I have a 93 4.0 in my B2.When I first put the motor in it had a high idle .First you need to look for vacuum leaks mine was only 1800 rpm's but didn't have leaks.You need to check the iac unit on your intake manifold unplug it and see if your idle changes to help to see if you need a new iac.I wound up putting in a bypass switch on my iac in my cab for low idle situations but hardly ever use it anymore idles nice now.There is a procedure for adjusting the idle with the iac use it can't just turn the screw randomly.If you have any questions what is an iac?where is my iac how do I adjust my iac?how to put a bypass switch on my iac? it's all in the web sight but hopefully you know where to start now.

P.S. I feel for you this stuff is very annoying and you can't just turn a screw it's hard to keep your patience.

 

[bert296]

so if i unplug the iac and it changes the idle i need a new one? i tried cleaning it and it didnt help ive looked everywhere for vacuum leaks cant find anything