I recently bought a 88 m3 for a very low price as is. I'm trying to pass emissions.According to the smog person, at idle I have low unburn fuel. HC PPM=338. I took it to the dealer and they told me it was the intake spacers gaskets which I bought there and installed them myself. The idle is still rough so at the recommendation of the archives, I've also replaced ignition wires, rotor, cap,o2 sensor coolant temp switch,fuel filter,and plugs. I even took it to our local college mechanic garage since my uncle is an instructor there and connected a machine that injects carbon dioxide smoke into the intake to check vaccum leaks one more time and there is none. I've check the tps and it checked ok. The only question I have is on the icv. Although resistance reading are 20,42,and 20 which is good, if the car is running, I unplug the icv and nothing happens, the idle doesn't rev up like on other regular e30 cars. Does this sound right? I've checked the plug that plugs to the icv and it has 12v. If I disconnect the o2 sensor, the car idles and runs smoother and doesn't hesistate as I start to speed up. BTW, the car has 211000 miles and the compression is 150 psi on all four at 5 cranks.

Just a quick idea, have you had the Throttle bodies synched, the CO set, and the base idle set?

One thing that I suggest to you is to run some Redline Injector cleaner. It will help clean all the carbon deposits out of the motor. It helped my car run better, meaning it started more smoothly, the idle was less spurradic, and it started easier.

Good luck, I'm really inexperienced with these sorts of things, so hopefully someone knowledgable will chime in.

[QUOTE]Originally posted by Bry
[B]Just a quick idea, have you had the Throttle bodies synched, the CO set, and the base idle set?

Yeah that's next on my list for tomorrow. I clean the injectors already and they all have the same identical spray pattern. I'm also going to take out the icv and clean it. Thanks for input.