Howdy and Help

[YoterDan]

I'm a newby here, I've been lurking for a while and thought I'd jump in.. I've got an '86 4runner sr5 with 144000 +/- 5 speed 22re, all the good stuff. Just one thing, it recently developed a really high idle. It cranks every time but immediately goes to about a 2100-2200 rpm idle, it sounds like it varies between 2100 to 2300 rpm's but the tach doesn't seem to show it. After it gets warmed up, it idles at 1500 to 1700 rpm's unless I push the brakes in in which case it goes down below 1000 and idles like it should. This high idle is killing me...

 

[KidVermicious]

If your idle drops when you hit the brakes, that's a sign of a vacuum leak in the booster.

I'm not sure how you could be idling that high without the tach showing it, but high idle is caused lots of times by a bad idle air controller.

 

[YoterDan]

I'm sorry, I should clarify that, the tach does show 21-2200 rpm's, it just doesn't jump even though I can hear the rpm's change. I've read that there is a plenum(diaphragm?) in the brake booster that sometimes will leak (given sufficient age and wear).

 

[KidVermicious]

I've read that there is a plenum(diaphragm?) in the brake booster that sometimes will leak (given sufficient age and wear).

Yup, that's why your idle is dropping when you hit the brakes. You've got two different troubles.