Hi guys,

First time it happens, have started Jag (-8 C* outside, was -24 C* day before), RPM went down after like 4-5 seconds and engine stalled.

I had to keep pressing gas pedal, otherwise RPM would just dance and go down. After 3-4 minutes, it was working fine.

Could this be related to stepper motor?

Also, last few times, I noticed, that when going R (engine warmed up for ~10 minutes), need to press a gas pedal as well, otherwise engine stalls (could it be due to some ice particles in cylinders or whatever, so it just needs a little bit more power?)

Appreciate your replies.

 

Sounds like the IAC motor is bad, Idle Air Control.

 

It happend today again, can engine diagnosis find this issue? Or there are specific tests for that?

 

Usually on idle the IAC should be at around 5 to 8% opened but you need a scanner to see the position of the position. If it is it is possible that your throttle body is dirty and not allow air to pass through. Oh check the TPS and make sure it's opened, should be 8 to 12 degrees. If it is you need to open up the throttle and spray some Brake cleaner at the throttle blade and wipe them dry, especially around where the blade is close to the bore. Put everything back together and start the engine. It will run rough at first till the brake clean is all burnt out, then it should run smooth again and should idle at that time.......

Alan.