3 Cylinders !!

[Stephen Pook]

Looking to pick someones brains here.

My E36 M3 Evo frequently cuts off the injectors to the front three cylinders. It gives a lamda sensor fault code. Lambda sensor has been replaced and situation is the same. Local dealer has reloaded the ECU software (Nearly £100 )... no difference. Dealer suggests changing the idle control valve, the ECU and the loom in that order but with no particularly convincing rationale other thn it could be one of those things!! Not a very economic method of diagnosis.

I have the car with a local very knowledgable specialist and he is also bemused. He is inclined to agree that the ECU may be the culprit but I wanted to check to see if anyone had come across this type of fault before. BTW the fault occurs when the car is hot or cold and being driven slowly or enthusiastically so it does not appear to be anything to do with temperature. Also the coils have been switched around and it is still the front three injectors that become shut off.

Any good suggestions as to the cause of the problem would be most welcombe.

Thanks.

[bullitt rich]

My suggestion would be to check the loom and the connections for breaks or corrosion on the terminals. If its the front three it may be that they're more exposed to water. I know you said you'd swapped the coils but have you checked the spark plugs as well? Its what I'd do tbh, gotta admit we've not had anything like this at our dealership.

[Stephen Pook]

Thanks Rich , that's helpful.

I think I'll get the wiring thoroughly checked anyway. The mechanic said that the spark plugs all looked ok with no signs of poor mixtures or combustion.