Odd problem with my '93 318is.

[Flaxmoore]

Went out to start the car today, and it ran for about a half-second, then sputtered and died. I tried again, and it repeated. The car runs, but only under load. If I take my foot off the pedal, it dies.

Pulling the code with a BavAuto reader was #36- Control Unit Supply. Looking online for clues as to what to do, I did the following on various bits of advice.

Checked the voltage at the battery while not running: 12.4V.
Removed the DME and let sit for 15 minutes to reset. Reinstalled, tried again, no change.
The walkthrough I found claimed a bad DME, purchased a used one from a '94 318i for $30, installed. Now it runs, but only under load. Take my foot off the pedal and it dies.

What from here? I'm seeing a possible alternator issue, or should I pursue the DME further?

[Flaxmoore]

Now that I've calmed down a bit more, I'll flesh a little more history on the Red Storm...

Looking at the Bentley guide for "starts but stops immediately" it says the following:

1. Idle speed control valve faulty: assuming this is the same as the idle air control valve, that was replaced ca. 2007.
2. Large air intake system leak: nothing I can find.
3. CO content too low, check MAF. MAF was replaced about 2007.
4 and 5. ECM faults.

I pulled the blink codes and got 1215: MAF sensor. Now what?

[Jared at Pelican Parts]

Well, if the MAF sensor is faulty, the car will do exactly what you describe. MAF sesors seem to go out all the time. Even more so if you are running a K&N or other oiled air filter. The oil from the filter gets on the MAF sensor and fries it.

I think the Bentley has a procedure for checking the MAF. You can try cleaning the MAF as well. Sometimes you get lucky.

[Jared at Pelican Parts]

Oh yeah, one other thing..

You can only use a DME in your car that has the same number as the old one. Also, read up on this here...

Pelican Technical Article: BMW DME Motronic ECU Swap / Repair

This is the number one cause of DME failure on these cars..