Author Topic: MAF sensors (Read 4118 times)

mwilderl · « **on:** June 17, 2010, 01:45:24 PM »

Do all M42s have the same mass air flow sensor? I'm in the process of trying to find a used one for my e21 m42 project and i want to be sure so i don't have to buy two.

DesktopDave · « **Reply #1 on:** June 17, 2010, 02:23:52 PM »

I believe they all do. The system changed mid-90s with the M44 to hot-wire and OBD II. I recall seeing a cross-reference somewhere that showed a few other cars that had compatible Bosch MAFs with that newer round connector.

IIRC The M20/M30/M70 has one that's internally similar but the connector is different.

deekay · « **Reply #2 on:** June 17, 2010, 03:16:36 PM »

no M42s have a MAF (which is what a hot-wire sensor is).

they have a flapping-door-style air-flow meter (AFM).

M42 AFM looks like this:

M44 MAF looks like this:

apologies if i sound patronizing, i just don't want you to buy the wrong thing from a similar-but-not-the-same engine.

if you are from the US, i would buy an air-flow meter from the same generation as your donor engine's ECU (either e30 or pre-95 e36) just to be safe... but the ECU pinouts are the same between the two, so if you can't find an exact match you may be able to get away with risking it.

mwilderl · « **Reply #3 on:** June 17, 2010, 04:02:42 PM »

Well I'm only 18 so I'm used to it!

Thanks for the info

Sean_318is · « **Reply #4 on:** June 24, 2010, 06:00:04 AM »

GM UK/Europe (Vauxhall and Opel) cars used the same Bosch AFM as the M42 in early 90's cars like the Cavalier etc, I know cos we have a box full of faulty/test units in the workshop!