i've got a 92 pickup dx 22re, 4x4, 5 speed...

my problem is that when the motor warms up with foot on the brake the idle surges up and down. it does it while slowing down, and when completely stopped. take my foot off the brake and it stops. if i put the t-case in 4hi or low, with foot on the brake it idles normal

has anyone else had the same or similar problem?

 

Vacume leak somewhere, maybe around the brake booster?

 

sounds like brake booster

 

Mine does that too, but with the AC on...With the AC off it idles fine.

 

Yours sounds like the ac idle up valve

 

i thought it was the brake booster too, so i capped the line and it still does it...

 

Mine was doing that, On the trails it wasnt...

I just went and got smoged and apparently the tech said it was idling high period...He turned it down and passed smog No prob...
As I left no more random idle...But, No my brakes keep loosing the stiffness..So idk, Maybe the idle is a tad too low...But yeah, Just turn the idle screw down a bit...
When It starts to bog down...turn it barely up...




EDIT:
Idle screw = flat head screw at bottom right corner of this pic, On top left of throttle body...

 

thanks scuba, that fixed it...