94 740iL SHUTS OFF when I stop!
 

Good Evening,

My e32 has a few problems but most important first, I'm supposed to drive cross country in a few days...

the car shuts off when I come to a hard stop, even gradual stops at times. the rpms just die all the way down to zero.

the symptoms are:

*It only happens once the engine has warmed up (15-20 minutes of driving)
*slow roll to a stop and it's fine, maybe the rpm's dip under 500 briefly
*if i put the car in neutral and stop hard it never dies

so it has to be in gear and the car has to be warm and it will happen guaranteed and repeatedly

Any suggestions for a fix, can I be directed to a thread?

*the mechanics computer reads error in the "transmission switch" but i believe this is only related to why my car gets stuck in on gear sometimes and my dash reads "trans program"

Thank you all,

Nick

i think it would have something to do with your tranny because it doesnt do it in neutral. that being said, if you stop at the traffic light and very lightly tap the gas(while still holding the brakes) does it shut off?

... that's what I'm afraid of... the tranny switch is under the center console and runs $500 factory (thats what my mech. tells me)

I also have an intuition that it could be the idler air flow meter, that when the car slows down it's not recognizing the decreased air flow...(silver cylinder at the front of the engine)

I'll try the gas tapping technique... what will that tell me (if tapping the gas prevents it from stalling)?

if it prevents it from stalling then it is possible it isnt the switch

If the gas tap works then it might be something to do with the airflow.

I was at the mechanics' again this morning and the computer read different...

Rotat. sp- signal

I'm leaving boston for several months so I'll have to take the lead on this problem

any ideas on the Read Out above?

p.s. All of your assistance is greatly appreciated -

I haven't had the opportunity to test the gas tap when I drove it this morning... but usually the stall is so instantaneous that you wouldn't be able to react fast enough

I am limited on money, although I have enough invested in the car now that I refuse to o turn back

So I wanted to check the cheapest fixes first:

As I mentioned above, it doesn't stall when the engine (or outside temp) is really cold which leads me to think air flow, maybe a larger air intake, or cold air intake...

the air intake inlet on the 740 stock is something like 2.5 inch diameter in an awkward location - is this a silly thought process?

My guess if its related to the intake is that you have a cracked intake boot or something causing it to loose pressure when not moving at speed and cause it to die. Might want to take a good look at it and see if there are any cracks or holes in the boot or whatever the connection is.

Alright, thanks alot.

I'll probably post again this Saturday afternoon.

KIT

-Nick

So I know it's been weeks since I said I would post, but I can be happy that my e32 made it across country. 4 Days and 3000+ miles later!!!

This post is in response to the question: "does the car still stall if you apply gas once the rpms begin struggling?"

NO! And as well I noticed that when I'm quickly decelerating to a stop and the car begins to stall if I let up on the brake I can save it!!!

This still happens all too often, so I'd like to solve the problem

I had a mechanic plug his computer in.. "Rotational Speed Signal" was the error

ANY IDEAS? - 1994 e32 740iL

hi don't know if its sorted but i had the same problem with my 728i, i had to replace the crankshaft sensor. The car works fine after that. Hope it helps

Hi there, sounds to me like it is the Mass Air Flow Meter. I had a similar problem last year on my 730. New Mass Air Flow meters are fairly cheap to buy and are a doddle to do it yourself. Should take you no more than 30 mins to remove the old n install new...

Thanks for your input! It's been a while since I've been logged on.. .the 94 740iL is long gone now and i'm nurturing a '89 535i with a new red paint job! ;)