Hello, I have been a long time follower, but this is my first time posting. I have a 1986 325e that I have owned for about 6 months. Since purchase, the car has run good, but slightly rich; however, every other run cycle the car will suddenly go pig rich and become undrivable. the only thing that I have found to temporarily fix this is to unplug the idle air control valve and let it run in it's default mode for a few seconds and plug it back in. After I have done that it goes back to running normal for a while.
the following parts have been replaced:
blue top coolant sensor
two prong coolant sensor
brown top coolant sensor
rebuilt injectors
fuel pressure regulator
afm
oxygen sensor
distributor rotor and cap
I checked the cold start valve and that is not leaking. Throttle position sensor checks out. I cleaned the idle control valve. I checked the fuel pressure during the malfunction and it is within range. I checked the sensor inputs at the ecu and they check out to the specifications in Bentley. Looked it over for obvious vacuum leaks, and haven't found any. I also cleaned the throttle body.
The fact that I can unplug the idle control valve and plug it back in for a temporary fix is leading me to believe that I have an issue with the ecu or the idle control unit. However I do not have access to spares of either to test with, and I am not sure if I am even on the correct path. Any advice would be greatly appreciated.
the following parts have been replaced:
blue top coolant sensor
two prong coolant sensor
brown top coolant sensor
rebuilt injectors
fuel pressure regulator
afm
oxygen sensor
distributor rotor and cap
I checked the cold start valve and that is not leaking. Throttle position sensor checks out. I cleaned the idle control valve. I checked the fuel pressure during the malfunction and it is within range. I checked the sensor inputs at the ecu and they check out to the specifications in Bentley. Looked it over for obvious vacuum leaks, and haven't found any. I also cleaned the throttle body.
The fact that I can unplug the idle control valve and plug it back in for a temporary fix is leading me to believe that I have an issue with the ecu or the idle control unit. However I do not have access to spares of either to test with, and I am not sure if I am even on the correct path. Any advice would be greatly appreciated.
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