I'm trying to test my IAC. When the ignition is turned and the device is plugged in, it pops open and immediately closes again. Is this correct operation? Voltage probed at the input leads is steady. If I apply 12V to the IAC it stays open. So why closing immediately when plugged in? My problem is that the engine wont start. Fuel pumps and relay are ok. I have fault codes 321 223 and 132. This is a 740 GL wagon.

 

A little more research has me suspecting the vehicle speed sensor, also the abs light recently came on. I can start the car with ether. Does anyone have any advice, or can point me to the location of the vss.

 

The IAC won't cause a no start.

If you mean the engine speed sensor, or crank position sensor, it is mounted at the top of the bell housing behind the engine. Hard to get at. The only way I know to test it is to replace it with a known good one. You can see it, or you can feel it. But you can't do both at the same time without a mirror and extensions. Be careful with the bracket. If you break it you have to drop the tranny to get at it.

 

Thanks for replying. After fiddling around today, suddenly it is starting. Didn't do much. Removed and reattached harness at the ECU, wiggled two relays mounted near coolant bottle and moved around the fuel injectors. After it started I did swap the two relays. So, I still haven't narrowed the problem down.

 

is it about to stall when you first start it (about 500 rpms), Then when you drive it and come to a stop, then does the engine idle about 1200-1500 rpms when you take it out of gear?

 

I have noticed a change in the idle as you described. So, yes. In fact, once after starting with ether I had to keep my foot on the pedal to keep it from stalling. In several minutes it began to idle. After clearing the engine fault codes and running, I now get one code, 321, the cold start sensor. Will this cause a no start?

 

could be the cold start sensor is not attached to the wire harness or not grounded. check and see if the terminals are connected securely.

 

Why on my 940 gle is there a port on the air filter box (above the level of the filter) where it looks like a hose should be attached? Wouldn't this let unfiltered air into the intake? Should I block it off?