1995 318is : Irregular Stalling

[tuxie95]

Irregular stalling. Sometimes it will not happen for days, sometimes a week or so. When it happens, engine shuts off, but will start again. There are no computer codes (which is very frustrating). I have checked for vacuum leaks...zilch!!--Other than that engine is very smooth.

--What should I look for???????

[BMWCowboy]

Sounds like cam or crankshaft sensor-->but usually will leave a code
exactley when does it cutoff>>low rpms??

[tuxie95]

Most of the time it happens in low RPMs, like when you slow for a traffic light or when making a right turn.

[CPTON]

did you fix this?

[frankzen]

I hate it when people leave posts hanging!!

My 318 i is doing this. Start it, it starts then rpms drop off to about 200 and it will stall or almost stall, hit the gas and it'll be ok, if not it'll stall.

[CPTON]

Originally posted by frankzen
I hate it when people leave posts hanging!!

My 318 i is doing this. Start it, it starts then rpms drop off to about 200 and it will stall or almost stall, hit the gas and it'll be ok, if not it'll stall.

yup i still have this problem, just did it again today, i noticed that when my car is normal that the air fuel gauge bounces but when it is about to stall it just has all the orange lights lite up and not bouncing, im thinking it is fuel related.

it cant be vacuum because it runs fine almost all the time just every so often stalls and it will start up again right after and affter a minute or so idles fine.

i doubt its spark i have new spark plugs and i dont have any hesitation when driving.

air filters clean


so i think it could be these things

fuel pressure
carbon canister
dme

[Wayne 962]

Double and triple check the air intake boot - these crack and can't usually be seen unless you remove it...

-Wayne

[frankzen]

Air intake boot ?? I'm a new BMW owner.

[CPTON]

Originally posted by Wayne at Pelican Parts
Double and triple check the air intake boot - these crack and can't usually be seen unless you remove it...

-Wayne

yeah but if it was cracked why would it only stall some times and idle steady and fine even with a/c other times.

mine has a hole in it but i siliconed it from the inside and the outside. its been like that since ive owned it and this problem has only happend in the last 6 months

[Wayne 962]

Originally posted by CPTON
yeah but if it was cracked why would it only stall some times and idle steady and fine even with a/c other times.

mine has a hole in it but i siliconed it from the inside and the outside. its been like that since ive owned it and this problem has only happend in the last 6 months

Temperature, the boot expands and contracts. I had the same problem on my 318, and when I took the boot off to inspect it, it had a big crack in it that I could not see when it was installed on the car. Silicone = bad, it will leak eventually. These are like $20 and about 3 minutes to install:

http://www.pelicanparts.com/cgi-bin/ksearch/PEL_search2.cgi?command=show_part_page&please_wait=N&make=BMW&model=BE36&section=fuelij&page=1&bookmark=5&part_number=BW-13-54-1-738-757

-Wayne

[Wayne 962]

Originally posted by frankzen
Air intake boot ?? I'm a new BMW owner.

Here's a handy photo:



-Wayne

[CPTON]

Originally posted by Wayne at Pelican Parts
Here's a handy photo:



-Wayne

i guess it wouldnt hurt to try it, i just bought a bunch of stuff from you guys wish i would have known then, shipping and customs = sux.

i also have a crack in the fuel sending unit but i glued that puppy up too, what do you think of that?

[frankzen]

Originally posted by Wayne at Pelican Parts
Here's a handy photo:


-Wayne

Thanks Wayne - that'll help.

Whats happened this morning - drove 5 miles...parked the car at a mall, came out 10 minutes later, car started and stalled 2 or 3 times and the check engine light came on for the first time! I'll have to try the gas pedal trick to get the code(s).

[CPTON]

Originally posted by frankzen
Thanks Wayne - that'll help.

Whats happened this morning - drove 5 miles...parked the car at a mall, came out 10 minutes later, car started and stalled 2 or 3 times and the check engine light came on for the first time! I'll have to try the gas pedal trick to get the code(s).

yes post the code

[frankzen]

Originally posted by CPTON
yes post the code

Did the gas pedal trick and got 1215....several times as a matter of fact - 1215 is a mass airflow problem...but the MAF on my car has been replaced...so I am beginning to suspect the intake bellows, even though I took it off and it looked in good shape, even between the bumps. I'll get a new one...and install it so we'll see what happens.

[Wayne 962]

Originally posted by frankzen
Did the gas pedal trick and got 1215....several times as a matter of fact - 1215 is a mass airflow problem...but the MAF on my car has been replaced...so I am beginning to suspect the intake bellows, even though I took it off and it looked in good shape, even between the bumps. I'll get a new one...and install it so we'll see what happens.

BINGO - that's the same exact code that mine was pulling when the boot had a big crack in it. It will be intermittant depending upon temperature - check the boot!

What happens is there is then a huge loss of vacuum, yet the other sensor read air coming in, when the air is bypassing the MAF. That leads to a MAF sensor error. 9 times out of ten, that code is a vacuum leak in the boot...

-Wayne

[CPTON]

Originally posted by Wayne at Pelican Parts
BINGO - that's the same exact code that mine was pulling when the boot had a big crack in it. It will be intermittant depending upon temperature - check the boot!

What happens is there is then a huge loss of vacuum, yet the other sensor read air coming in, when the air is bypassing the MAF. That leads to a MAF sensor error. 9 times out of ten, that code is a vacuum leak in the boot...

-Wayne

I can never seem to duplicate the problem when i want to so i can test things. But today it was hot so when i got home i turned the a/c on which usually makes the idle bounce a bit then settle down and today it was fine. So i started squeeziung the intake boot and bending it in spots and nothing happened, so im thinking i dont have the same problem as the guy above. Plus if it was the intake boot i dont see why it would start up after it stalls and run fine.

I drove my girlfirends precidia when it has a torn intake boot and man that thing wouldnt go anywhere, but maybe it was a bigger leak than what were talking about here.

Frankzen let us know what happens please.

[Wayne 962]

Originally posted by frankzen
Did the gas pedal trick and got 1215....several times as a matter of fact - 1215 is a mass airflow problem...but the MAF on my car has been replaced

Maybe it's a less-than perfect unit? The stalling problem is indeed indicative of a vacuum leak or perhaps a stuck flap in the MAF...

-Wayne

[frankzen]

Originally posted by Wayne at Pelican Parts
Maybe it's a less-than perfect unit? The stalling problem is indeed indicative of a vacuum leak or perhaps a stuck flap in the MAF...

-Wayne

Could be. The MAF unit the previous owner had installed was a used one from a scrapyard. I'll replace the bellows first and see what happens. The price of a new MAF is outrageous!

Frankzen

[CPTON]

i was pumping my brakes today while it was idling and usually it makes the idle go up a few 100 rmp but today it made it stumble and kind of choke. THe vacuum reads about 18 at idle and when i pump the brakes it goes to 15 and stumbles.

more and more its sounding like a vacuum leak, whats a good way of finding one? i tried spraying water all over, but didnt come up with anything, also tried the pipe idea with one end to my ear and the other scanning around the engine bay.