Member
I have a 2000 323Ci that has an issue starting up when the MAF is plugged in. As soon as it starts up it dies immediately. If i unplug the MAF Sensor then the car starts up just fine. I have replaced the MAF Sensor twice with brand new parts. Can somebody please chime in?
Member
Were these new OEM VDO/Siemens brand or cheap EBay Chinese crap?Originally Posted by youabustah
Wagon meister :)
BMW Tech Expert
+1
The other issue can be a gross vacuum leak, check every line for cracks, splits, and busted open.
Darin
Current:
16 220i Active Tourer Platinsilver MET (C08)/Dakota Black (PDSW), P7ACA, P7LDA, P7LHA, P9BDA, 6sp Manual - Wife's new toy!
05 325it Electric Red(438)/Gray(N6TT) ZCW, ZSP 5sp Manual Back set cover, trunk mat, Euro Infra-Rot front windshield, and mud flaps! Mr. Wagon My new Winter car.
05 M3 Imolarot II(405)/Gray(N5TT) ZCW, ZPP 6sp Manual C.F. Lip, CSL diffuser, SSK, Euro Infra-Rot front windshield and a trunk liner! Mr. Go_Fast Stored for the Winter
Past:
95 318is Montreal Blue Met (297)/Beige(K1SN) RIP, killed by an Idiot.
84 M535i gray market Burgandy Rot Met/Black Leather Lowered by Intrax on bilies, poly everywhere, B&B cat back system, K&N, and a hitch! Da Beast - Still running w/400k+!
91 316i euro Tizianrot/Gray cloth - E-36 w/M-40 RIP, but great on gas! Best was 38 MPG
82 528i euro Saphire Blue Met/Blue Leather RIP
79 525 euro Green/Green RIP
79 318 Silver/Black - The first one that got it all started
M-Flight Member
Member
Have you read the trouble codes? What are the short term fuel trims like e.g. >8%?
1999 2.8L Z3 Roadster,
2000 3.0L Z3 Roadster,
There is only one thing more pleasurable than working on a Z3, that's driving it top down on a fine day.
Member
Unplugging the MAF causes the engine computer (DME in BMWspeak) to revert to an overly rich fuel/air mixture. This masks vacuum leaks. The only way to find vacuum leaks is to smoke test the intake. The original MAF is most likely ok.
Member
It is a Bosch brand MAF
Member
With the MAF connected i am reading 0 on the Short Term Fuel Trims.
Member
I’m suspect of Bosch MAFs as the company has switch production of some of its parts to China. Put the original Siemens/VDO MAF back in the car. What tool are you using to scan the engine computer?
Member
Did you let the engine heat up before you checked those trims? An exact 0 looks like the DME saying 'dunno' because the catalyst and lambdas are still cold. Fuel trims are never an absolute 0.
Member
Mabye i am chasing the wrong thing, but i suspect it is not directly the MAF that is the issue. When the car is warmed up all the way and the MAF is plugged in, then the car will function as it should just fine. I am leaning towards a vaccum leak or something wrong with the DME. I had another MAF plugged into the car OUTSIDE of the intake and the car was running fine UNTIL i blew air into the MAF directly, the car then died immediately.
I am using an OBDLinx Bluetooth Scanner.
Member
I did have the car warmed up to temperature, and those were the reading i was getting. I agree the values should never be a 0.
Posting Permissions
Reply With Quote
Bookmarks