Hi all :facejump:
First time here so I hope I can find some help and relete the problem in a concise way.

I have a 1993 Magna 2.6 Ltr Automatic. It has been running well but has developed a strange variation when idling.
When started it will idle around 800 RPM. One push/rev on the throttle it will idle back to 1500rpm.
And variations of RPM in between. Turn off and start again and it will start at 800RPM and do a repeat.
So I backed off the idle screw until it was not touching the plate it pushes against and it will still idle between 500 and 1500 RPM.

Driving it can do the same thing.

I thought it must be the linkage from the excellerator but it remains slightly slack in the neautral position so I do not think the linkage is the problem.

What else could be causing this inconsistant idling.

Thanks Bazza

I have been investigating on the web getting ideas about my idling problem.
Im from the old school but I can see with these later cars a lot of things can effect idle.
Like
Engine Mgm Module
Stepper Motor
TPS sender
Air Con device idle up
ISC evidently a common problem
IAC
Some of these may be the same thing with a different name.

Any suggestions on the most likely first and how do I test it

Bazza2