Idling problems with a JDM 12AT engine

[myatt1972]

If this were a piston engined car I would be diving for the auxilary air valve, I have no idea about your turbo / fuel injection system but if it has such a thing I would be looking at it and its control, also with a fuel injection system there will be a temperature sender for the ecu, worth checking.

[KiwiDave]

Sticking throttle shaft or throttle position sensor?

[Traxnada]

Hum, OK I'll try and take a look at a possible sensor failing... Seems like I'll struggle a little for that lol.
Logically, where would one be positioned?
And I don't think it has to do with a throw problem. Idling being high only, it could be. But here it's fluctuating like a cammed v8 so I doubt it has much to do with that.

[KiwiDave]

I've asked around. Showed the video to Efi technician. He suggests fault with idle air control valve or vac leak at inlet manifold.

[Traxnada]

Awesome, thanks man! I'll go look at it a bit deeply this week end. I'll keep this thread updated with my progress!
I can only hope it's not a vacuum leak. Those 80's engines are a bit of a mess with vacuum hoses lol

[DKWW2000]

You can check for a Vacuum leak by spraying a solvent based spray eg WD 40 around the hoses, you will hear the revs change if there is.

[Th0m4s]

It could be that the thottle position sensor is out of adjustment or simply worn because of the high age or it might be a vacuum leak. I don't think the idle control valve is the cause because it looks like it is working but it's trying to adjust to something which shouldn't be there.

[Traxnada]

Noticed I never updated this... I found the culprit!
Believe it or not, but my A/C was responsible for that haha... The relay of the solenoid that raises the idling when the AC is on. No more problems now and it idles very smoothly