Changed the EGR but still the same.
Now it seems to be hunting.
2300 Rpm and then reduces close to idle speed and instantly right back up to 2300 Rpm and then back close to idle and back up to 2300.


Any suggestions?

 

Huh,

Did you try exchanging the IAC you bought for a different one (not the old one you replaced because you thought it was bad)?
Replacement parts are garbage, regardless of where they come from, many times it's taken 2-3 different parts before finding a good one.

Throttle Position Sensor will also cause idle issues. As can a faulty coolant temp sensor. As can a faulty MAP/MAF sensor.

Bad connections at any of the sensors can also cause issues.

 

Yes, it start to get really frustrating. Can't use the car.
I put back the old IAC, but no change. Now I got a used throttle body with position sensor and IAC. I will put it on this weekend. I hope for the best.

I will check the coolant sensor and MAP sensor at the same time.

Thank you

 

Check the wiring in those areas as well. It's very common for the wiring to get bad by the throttle body. It's also common for the connections to get bad.

 

Replaced the throttle body today. Still the same. Took a short video.


When I checked the MAP I instantly got the check engine light on in the dash. Reconnect and took of negative on battery and it was OK again.
As you can see on the video, when I block the throttle body inlet it runs at a steady 2300Rpm, when I take my hand off it start to hunt. Where does the car get the air from when I block the inlet? It has a brand new OEM EGR valve on it (just replaced it earlier).

All cable and connector are ok. No problem there.

Any suggestion?

Thank you

 

All vacuum lines are good, connected properly?
Nothing is leaking elsewhere? Smoke test?
Intake manifold itself leaking?
It has to be drawing air from somewhere it shouldn't be.

 

I have blanked off the EGR valve. I have plugged all vacuum hose inlet and checked all vacuum hoses and tubes. All OK. Only leak now can be in the intake manifold itself, but I have felt around it as far as can do and no leak can be observed. Are there any weak points for intake manifold cracks? Or can it leak around the fuel nozzles? How else can the engine run when everything is "plugged" and supposedly no air can pass?

So as per now still the same as in the video.

Any suggestions for further search?