Engine cuts out 1988 325i convertible

[oggy07]

Can anyone help.

My car runs ok and then for some reason it cuts out. rev counter
shows zero. Sometimes car will then jump back into life.
Other times I have to restart using ignition.
I have changed the plugs and oil but not done much else.
Thanks,
John

[Grrrmachine]

Telling us what car you have is a good place to start. There are four different engines in E30s.

[oggy07]

1988 325i convertible

Cheers,
John.

[Brianmoooore]

Rev. counter dropping out shows that this is a problem with the circuitry generating the pulses for the ignition coil.
This can be a failing crank position sensor (usually gets worse as the engine gets up to full temperature), the lead from the crank sensor being damaged by the water pump pulley where it passes behind it, the engine ECU itself (unusual), or a fault in the electrical supply to the ECU. This is most likely to be a failing DME relay, but could also be down to an immobiliser or two connected into the supply wire.

[oggy07]

Hello,

Thanks for reply, give me a few areas to look.
Interresting that you say about an immobilser as new battery seems to drain quickly,
i.e. after a week I need to put on charge. Car is only a sunday car so does not get used much.

Would an auto electrician be able to identify the problem ?

I think intitially I will check the wiring and then perhaps change DME relay.

Car first did it after picking it up after driving 70 miles, but now seems to do it every time I take it out.

Thanks again.
John.

[Brianmoooore]

Much easier to find a fault that puts in an appearance often, than one that occurs for five seconds once a fortnight.
DME relay can be checked by replacing it with a couple of wire links, joining together pin 30 and both 87s on its socket. Don't forget to remove the links when you stop the engine.
If there's an electrical drain, you can find it yourself. All you need is a £5 meter and the instructions in the wiki. E30s are the cheapest cars on the planet to run, but not if you keep taking them to a "professional". (Inverted commas intended.)

[oggy07]

Thanks again, I will do as you say and let you know the outcome.
Are there any meetings etc in the Yorkshire area ??

[Dynamicmetalsolutions]

1988 318i auto here. I've got a similar problem where it will just die. Not nessecarily under load or off load. It dosent cough and splutter, just plain stops. Sometimes I can start it on the throttle but the majority of the time it's into neutral coast for as long as I can and restart it. When I first got the car it did it a lot. Then It evened itself out. Now it just does it every so often. SO ANNOYING! Where would a good place to start be? The aforementioned places in the post?

[Brianmoooore]

Where would a good place to start be? The aforementioned places in the post?

Depends what YOUR tacho. does.

[e30rapidic]

sounds like a main relay issue.

[Dynamicmetalsolutions]

The tachometer just dies out with the engine as you would expect it to. (Which is a plus if your a loud music fan...) Sorry if I missed your point there?

[Brianmoooore]

If your tacho. dies with the engine, then your problem is completely different from the OP's.
Could still be the DME relay (different section) or could be something like a fuel pump problem.

[oggy07]

Hello,
Car is now running worse. Takes a couple of times to start and is now missing
and running poor. So I think whatever is going is getting worse?
Cheers,
John.

[oggy07]

Hello,

An update on my problem. Car would not start so had Green Flag home start out. They said spark was weak and checked coil, found to be out of specification. Got car started by drying plugs, but next day would not start. Bought second hand coil of ebay, started first time but was still missing. In the mean time I had bought second hand DME relay so I fit this also.

Since new DME relay has been fitted car has run perfect, only done 50 miles but so far so good.

I will keep you informed !!!!!!!

[Brianmoooore]

Weak spark wouldn't cause the tacho. to drop suddenly, but a duff DME relay would.
I gave instructions for checking that on Aug. 18th!

[oggy07]

Hello,
Thanks for your post, I did get another DME relay, but because of fault with coil car would
not start.
All seems ok now, but time will tell.
Cheers again,
John.