Momentary idle drop, very intermittent.

[BillRod]

Hi All

90 Bronco II, 2.9, Auto, 4x4. Odometer ready to roll over again...
Truck runs great but every once in a while at idle the rpm's will drop to almost stalling and of course the oil gauge will drop with it.

This is very inconsistent. I have been driving it the past week and it happened once last week and once today when I came to a stop light and it actually stalled as if I had turned off the key. Restarted immediately though.

I went through on a previous post and found a couple of small vacuum leaks and fixed them so no lean code anymore. Now it runs smooth as a top most all of the time, no issues under load or when driving or any thing.
Only the brief and as I said very intermittent drop.

I recall many years ago a car that had a similar issue and if I recall it was the idler motor or something like that.

Do these trucks have anything that controls the idle that I could look at?

Any info would be appreciated.

 

[Psychopete]

When it's stalling out, is it always like the key is being turned off?

The idle air control solenoid is on the passenger side intake plenum (top side about in the middle) - I am sure you have seen the cylinder shaped sensor looking thing on the side of the top of the intake - that is it.

 

[BillRod]

Cool! I know which component that is. Should be easy to replace.

Yes, that is what it acts like.
Apparently the idle has been intermittently dipping for a long time.
Only recently has it began to actually stall.

Thanks for the info!

Bill

 

[BillRod]

$77 later and the truck is running Great!

Thanks!!!
Bill