Car cuts out while running

[SeymourCake]

A very annoying incident happened today with my E30. I was driving and suddenly all power cut out while I was on the move. Luckily it happened just as I entered a car park. Would of been a headache if it was a busy road.

Every time I would start it, it would die out straight away soon as it tried to idle. So therefore it was not idling at all, unless I had my foot on the throttle, as soon as I would let go of the throttle, the revs would drop all the way and it would completely cut out.

I checked and sprayed the ICV with WD40, checked AFM, distributor cap, few other things but did not really have a clue what it was. Suddenly, TWO hours later, I started it again, and it idled perfectly. Everything was back to normal as if nothing happened. The car held idle and I drove home perfectly normal.

What could the issue be here? I will not be driving it again until this problem is fixed, dread to think of the worst places it could happen again.

edit:

one more point to add, the car cut out when i took a sharp turn.

[m_jermyn]

Crank angle sensor mate...


What motor is the e30?

[SeymourCake]

Its a 325i.

How much are they mate? Easy to fit?

[BadMoonRising]

Had something similar on my 320. It's pretty scary coming off a busy roundabout and the car dies.

First time was faulty AFM, second was Temp Sensor.

[SeymourCake]

Ah ok, I'm still not sure what it is...

seems like it can be a wide range of thing?

How do I find out what it could be?

Anyone else experienced this??

[grantorino]

My 86 325ES did this about a month ago. After replacing the main relay, it still did it. Turned out to be a faulty ICV. cleaning it with WD40 leaves a residue. I would use brake cleaner or throttle body cleaner. Mine would quit at very light throttle around 1100 RPM and coming to a stop. i didn't trust my ICV and got another. Its been faultless since.

[HairyScreech]

do check your fuel pump isnt stopping, they can start and stop at random when they are on there way out, you only have to listen for it pumping when turning the car over

[SeymourCake]

Yeah mate I think you may be onto something there.

My fuel pump has been whinning quite alot recently, even when there is plenty petrol in the tank. My first gut feeling was fuel pump aswell.

[SeymourCake]

anyone else have experience or knowledge on this?

[Brianmoooore]

What, exactly, does the rev. counter do when the engine cuts? Drop like a stone, or die as the engine dies?

[DaveD]

I had this about 6 weeks ago...kept totally cutting out when on the move ..ticked over ok..it would catch again and go for a bit then do it again ..tried everything ..in the end I suspected dirty fuel...filled her up again and it went away never to return..

[SeymourCake]

What, exactly, does the rev. counter do when the engine cuts? Drop like a stone, or die as the engine dies?

The revs dies as the engine dies..

[Brianmoooore]

What, exactly, does the rev. counter do when the engine cuts? Drop like a stone, or die as the engine dies?

The revs dies as the engine dies..

In that case it's far more likely to be a fuel supply fault than an ignition one.
Fuel pump is the prime suspect.

[SeymourCake]

Thanks Brian, what is the best method to test the fuel pump?

[assassin]

Ive got this problem on my touring (325), but my rev counter drops like a lead balloon. ??????

[Brianmoooore]

Thanks Brian, what is the best method to test the fuel pump?

Difficult to test something that only fails occasionally, but the next step should ideally to check whether power fails to the pump, rather than the pump just stops.
You need to connect a bulb or LED across the pump terminals, under the rear seat, position the bulb somewhere where you can see it while driving, and see if the bulb goes out before or after the car fails.

[SeymourCake]

im just a bit confused... is there a fuel pump under the rear seat or is it in the fuel tank??

my car is a 1988 cabriolet.

[Brianmoooore]

The fuel pump is in the tank, and is reached by removing an access panel under the rear seat.