No start issue

[Jeff48]

This is strange to say the least. Last night I drove home and parked the car without a single problem. This morning, after a very light shower through the night, the car would not idle at all. If I depress the accelerator, I can keep it running but it pops and barks and is rough as a dry corn cob. I threw the code reader on it and it says Mass Air Flow Sensor is in the sh*tter and the 02 sensor is dead.

So, I am at a loss as to this mystery break down. There was nothing different between last night and this morning except for the light shower. I would suspect the DME got wet except the car has been MUCH wetter without a problem. I am really frustrated with this car, please give me some advice.

I have the Bentley manual and I will be testing the MAF tonite but the whole scenario makes no sense whatsoever.

[bmwhighroller]

Unhook the cable that leads to your mass air flow sensor and start the car. If it works, thats your problem.

My MAF went like that too. Driving to school it was fine, and wehn i went to the car to leave, the car had similar symptoms to yours. i unhooked the wires and drove home no problem.

[Jeff48]

Thanks I will try that tonite.

All other suggestions still happily accepted

[Jeff48]

OK I went home for lunch and disconnected the MAF and it idles wildly between 500 and 1500 RPM but still pops and makes bad noises which make me worry. If I plug the MAF back in, it returns to no idle conditions.

Any MAF gurus out there. I am only familiar with MAP sensors and if you disconnect the vacuum hose to them completely they act like this a little but not so nasty. I have never tried to disconnect a MAP sensor's electrical hookup so my question is...

If you disconnect the MAF do you expect the car to run better?

HELP!!

[Jeff48]

Bump

[tomt30273]

If you disconnect the MAF, it should go into "limp home" mode. I should idle and run, just not very quickly. It still could be the MAF, but check for cracks around the boot that connects the MAF to the throttle body. And it could be your DME has decided to go south. Wish I could help futher, hard to do long distance.

[Jeff48]

Wouldn't the Peake tool (BavAuto Version) show a fried DME?