Every time when I hit the road, the engine just stalls when I let off the pedal at low speed. Doesn´t idle at all. No codes, running strong. Go home, wait a minute and it s Idling. Took the IAC motors out, cleaned and checked, were both moving about when staring and stopping. Checked the EGR, was terrible and cleaned, no change, Found a bad EGR control valve, disconnected the EGR, Idled much better when Idling, but stall problem...no change, balanced the TB´s, no change.
So I decided to disconnect both IAC motors when idling ok. Bingo.
So the motors behave weird, seem to close after a drive (reset) and open up when lucky. Fun to find the problem, now I have to find the bad spot.
Idle never was real fine, lots of positive and negative surges wich are gone after the motors have been disconnected, so the problem may be older..
If you had these experiences before and have a tip, please chime in before I hang upside down in the car chasing the wrong connectors and wiring.
Thanks
Nico

 

BOTH IAC motors-there's just one. Are you sure you're not unplugging the MAF?

 

The CFI has two TB´s, both equiped with an IAC motor. Because it are stepper motors I suppose that they are driven directly from the ECM. I am about to check that and start measuring and ispecting shortly. Didn´t have the time yet.

 

Well, that's something I didn't know, never had a CFI. Good question for CFI-EFI, now where is that devil

 

I agree, CFIIIIII, Where are you??????? We need you !!!!

 

Have you set Min Air Adjustment? Have you done any tuning? Can you scan the vehicle?

 

There seems to be no doubt that both IACs function. I'll assume you set the minimum air adjustment and balanced the TBs properly. It would appear that the ECM is sending undesirable commands and that the IAC are executing those commands correctly, or else there is a break or intermittent short in the IAC circuit(s). I reached that conclusion, because you say once it is idling properly and disconnect the plugs from the IACs it remains idling well. After you go over all the wires in and out of the IACs You can check sensors that might cause the ECM to command the IACs into doing strange things. I have never had anything like that to try to chase down, Keep us informed. I'll be thinking about this.

RACE ON!!!

 

Thnks for the info both.
The car is stock, I can not scan, made the adjustments, but it was the first time I ever did this, so......I will go over the adjustment once more, may have made a mistake. But unfortunately, I have to go to the Netherlands coming week, so it will be delayed a week. But I will open a new thread with the results in order to keep in touch
Regards