e30 keeps stalling, bad idle, no speedometer

[svenga]

So I'll keep this short..

1989 325i convertible..

Entered a roundabout, car stalled.. Started back up and carried on driving, problem happened again, twice!..

Battery and ignition must be ok as the car starts fine, however it runs a little bit rough for so long, then dies. No visible leaks, no warning lights.. And no MPH gauge!

Any ideas!?

All help highly appreciated!

[bosers]

Does it die when cornering, mostly?

[svenga]

No, the car has died idling and driving straight..

I got at least two minutes between each stall after the first time, mainly when shifting into second gear.. Then my girlfriend noticed I had no speedometer..

Ran the car stationery checking for issues, AFM works fine, ICV never did anything when I unplugged it. No visible leaks, no fuses blown.. Played with the revs a little, car cut out.

Somebody said it could be coil leads and rotor, but surely the car would not run let alone start..

Could it be the crank position sensor with an intermittent fault?

[svenga]

From what I remember (whilst panicking on the road!).. When the engine died all dash lights came on..

Whilst driving along there was no speedometer but all over gauges worked fine.

Sprayed the AFM, ICV, plug under the manifold, this morning and it started fine again but never had enough time to see if it stalled.

Somebody mentioned intermittent CPS but would this relay with the speedometer??.. I thought the speedometer worked from the diff.

[jmc330i]

When the car stalls, does the revcounter die in line with the dropping rpm or drop like a stone to 0?

Whilst driving along there was no speedometer but all over gauges worked fine.

Somebody mentioned intermittent CPS but would this relay with the speedometer??.. I thought the speedometer worked from the diff.

Revcounter, not speedometer

[Brianmoooore]

I have a theory if the rev. counter does NOT drop like a stone, but we really do need to know exactly how it behaves when the fault occurs before going any further with the diagnosis.

[svenga]

I will check when I finish work Brian, I think it does but to be sure I'll sit in the car and watch it closely!

[svenga]

To add I have just remembered..

Whilst driving and the problem occurs, firstly.. there will be no throttle response for a few seconds, try to rev it and nothing just returns to idle and then cuts out with all engine lights on display.

Just incase that is another pointer to the problem

[svenga]

Started to look at the car as soon as I finished work..

With contact cleaner, Sprayed the CPS plug & cleaned the sensor unit. Blue and brown sensor plugs, plug under the intake manifold, main multi plug & cap, AFM plug, ICV plug, the battery terminals and earths, pump relay under the black cover, relays in the fuse compartment.

Started the car and it idled lumpy, let it warm up, revved it a little and drove back and forth and it was stil abit rough.. Then as I wasn't looking the car stalled.. Tried to start it again, fired but only for 1- seconds and then stalled, this happened twice before finally firing and again running unsettled.

Removed the ICV and assosciated hoses and rubber boot, cleaned them all and checked for splits (the ICV was quite oily). Replaced and started the engine again, again a little unsettled..

Sod it time for a drive and see what happens. Ran a little unsettled to the end of the street, pulled away speedometer was working again and had a 10-15 drive with no hiccups and mixed settled and racey driving, since I have done another 15-20 miles and seems OK

What exactly was wrong I do not know! No doubt it will come back to haunt me but cleaning the above seems to of solved the issue FOR NOW!

What was your theory Brian?

Cheers.

[Brianmoooore]

You have done everything you shouldn't have done! You should never disturb ANYTHING that it isn't essential to disturb until you have identified the cause of the problem by observation and measurement.
If you had observed the rev. counter, as asked, we would be well on the way to identifying the problem.

[svenga]

Brian, I did observe the rev counter before carrying out what I did (need the car for today with no choice I had to try something even if I have jeopardised problem solving)..

The rev counter dropped smoothly and fast.. But not like a stone to 0 or bounced..

My rev counter once the engine has cut out/turned off after a few seconds actually bounces/purges once and has done since owning the car.

[Brianmoooore]

If the tacho. dropped slowly, then it's considerably less likely to be an engine related electrical fault than if it had dropped instantly, so most of what you have done is not likely to have been relevant, and was more likely to introduce a fault that wasn't there originally. For instance, the CPS wire is often brittle, but is fine if left alone. Moving it may crack it, letting in moisture which will eventually cause it to fail.
Going by your description, your engine problems might have been as the result of poor and intermittent fuel pressure. The fuel pump and speedo. sensor share a common wiring loom along the LH side of the car, through a plug and socket on the RH side of the rear seat pan, and then down through the pan to underneath the car, where they split and go their separate ways.
I'd be checking that the plug and socket under the rear seat is pushed together properly, and/or looking for any other problems along the path of that loom.
The bounce you see on the tacho. after you switch off is one of the peculiar faults that the lithium battery powered version of the SI board in the instrument cluster often develops.

[svenga]

Removed the rear seat and checked and sprayed both yellow and single multiplug..

The wiring looks OK but who knows what it is like inside the PVC sheaving.. One to watch!

Thank you Brian for your advice!