Commander 950 idle issues

[DeltaT]

First I would open the 950 software, then go to 'About', click on 'Version' and make sure that the 'Advanced User' box is selected. This enables you to see a few more variables that are important to your problem. I would try playing with the 'Proportional' value in the "HW Settings', 'Idle Air Control' window. Try lowering it to 50, and see if that fixes your problem. If it doesn't put it back to where it was and try the next - you can always fine tune it later.

After trying the above, then it sounds like the known noise issue with the IAC could be affecting you. There's an embedded workaround in the unit, if you are running a later version:

Make sure under IDLE AIR CONTROL that you have the MINIMUM IAC POSITION SET TO 0 for the idle area. IE, if your idle TPS is 36, make sure the first 4 boxes (from the left) are set to 0. This enables the fix in the firmware. Any other value other than 0 won't enable it.

Go and drive and see if that fixes your problem.

This enables some 'filtering' logic that can help deal with noise generated by the WBO2 controller that confuses the IAC motor and allows it to get out of position.

Other things that may help: Separate ground for the WBO2 controller; ensure your 950 Case has a good connection to ground; try to route the IAC wires away from high voltage wires.



Like Jody says, come on over to Chevytalk 'EFI/fuel injection and Engine Control Systems'. It's a large 950 and other EFI community.

Jim