E34 M20 Misfiring at idle speeds and running rich. HELP!.

[bustedbmw]

Hello everybody. I've got a problem I can not seem to fix. My m20 runs so rich I can smell the gas coming out the exhaust. She misfires so bad at idle that it makes me want to eat popcorn! Just today I found that my fuel return line was clogged, so I flushed it out(you wouldn't believe the amount of black nasty stuff that spewed from the line!). It helped with the performance, but not the misfiring. I suspected the ignition coil, and the primary resistance check out good, but the secondary was about 9,640 ohms. Haynes manual states 5,000-6,000 as the proper specs. Would a bad ignition coil cause a rich condition? Any other ideas as to what i should check? Maybe the temp sensor?

[David325e]

Replace the coil and see if that helps. Also check any and all fuel hoses for cracks or breaks. As well as the air boot and air intake. See if the air filter is good. If the fuel return hose was that bad, flush out the fuel feed line and when was the last time the fuel filter was replaced?

If they are original then t may be a good time to replace the ignition wires. Thats a common wear item on these old M20s. And once you get the issue fixed change the plugs.

Get a bottle of MAF cleaner and use it to clean the idle control vavle and the throttle body. While the car is idling spray the cleaner around the valve cover, the throttle body, etc and see if idle pics up. If it does you have a vacuum leak there.

[bustedbmw]

Alright I'll try the coil. The intake boot is original and has some dry checking but I can't hear any whistling coming from it. I've cleaned and gapped the plugs not too long ago(actually in pursuit of the same problem) and the rotor and cap are new. I am not sure about the wires, they visually look good, but ya never know right? The icv is new also.

Is there a way to test ignition wires besides the old stick your head in there at night and look for the blue light?