Hi all.
Hoping someone can help me solve this mystery... I have a 1989 22RE, got this truck a few months ago and been slowly working out the bugs, but need some help on this issue. I’m getting a surging idle around 1000rpm ****ONLY**** when I’m in two wheel drive, coming to a stop/idling. It doesn’t happen all the time, and quits as soon as I throw it into 4x4. Been trying to pin down the exact variables contributing to the surging idle but it seems somewhat random. When it does happen, it’s usually when I’m at a stop, or coming to a stop, in neutral, but it has happened in first gear. If I’m at a stop and this is happening, it’ll quit for a moment when I tap the gas, but it eventually starts up again. But the problem doesn’t happen with every stop...

I saw a thread where someone had pretty much the exact situation, turned out to be brake booster failing. This was all happening and then my booster also ˟˟˟˟ the bed, I replaced it, thought that would be the end of it, but nope.... same symptoms (though now a working brake booster).

Tried the standard vacuum leak test with the engine running, carb cleaner etc but that turned up nothing. Really not sure where to proceed here, any help would be greatly appreciated! Thanks.

 

Mine surges if the idle is too high and I press the brake pedal. The fuel cutoff (I think) will cut every 750ms (about)
In 4WD It just idles high.

Can also be the TPS sensor. 4crawler has a nice writeup to test that.

Link to another thread about it: https://www.yotatech.com/forums/f116...e-22re-195583/

 

On my 92 22RE that was doing it randomly, it was a bad idle air control valve that was causing the surging. Has not done it since I installed new one back in October 2018.

https://www.yotatech.com/forums/f116...stions-305617/

 

 

 

My truck is in my signature...2wd 5 speed, so I can't help you with 4wd.

 

My 1990 4runner 22re has the same surging idle, only in 2wd. As soon as I put it in 4wd it idles fine. Did you ever find the cause??