dicer

Many times the ECU has been blamed, and been fixed or replaced and still there is a high idle or surge, basically it just does not want to idle right.
My one car was exhibiting those conditions, I replaced the idle air control assembly with one that looked nice from a wrecking yard and it actually made it worse.
So finally dug into it today and discovered either one of the bearings went bad or the screw that opens and closes the valve it was frozen wide open. I have not replaced it yet, but I'm sure this is the problem with lots of these cars. After the many years the bearings or other moving parts are just lacking the lubrication to work correctly since this is a stepper motor and in constant movement when idling any extra load that restricts it is going to cause problems. So I'll keep this updated to how it changes things.
So along with the ecu, this item should also be on the list when idle and drivability problems arise.

Legender

Interesting find. Keep us posted on your continued investigation.

wnyjazz

Agreed.

timmy0tool

iTrader: (7)

check this out!
http://planetsoarer.com/IAC/iac.htm

Legender

Timmy, that's a nice find on a nice write up... thanks for sharing.

dicer

Good find, saves me the trouble of pictures etc.

python

iTrader: (4)

https://www.clublexus.com/forums/ls-...-macgyver.html

dicer

Its funny this all has never come up when all the people have had the problems, like Magda and many others that I don't remember. No one ever spoke up that I remember and linked to the bearing problems in these IAC motors. Evidently they are not very well lubed and you would not want a thick lube on them for the cold climates, it is a big problem with them. At least the last one I found at a wrecking yard looked like new on the outside and to my surprise on the inside and bearings as well. This problem is just as big as the capacitor issue in the ECU's and will cause the same sort of drivability problems. I would guess that most all the funky engine running problems are either this or the ECU, and in 93 -94's I'm thinking the EGR can be a problem as well since they look like a similar to IAC motor on them.

dicer

So I put some very light oil on the screw and also the bearing area for it, and since its like new the ball bearings left untouched. Reassembled it of course making sure its in wide open position. And got the car running and its doing just fine, idles nicely.
If you search for the runability problem Magda had it is about what mine was doing. This is the fix for it.

Legender

Thanks for the follow up and letting us know what worked.