Non runner...l1984 635csi UK Euro model end Vin 8185999

[themack]

Hi all,
Been attempting to get my old E24 going. Before I bought it had been attacked for the stereo so the wiring in the cabin is dangling everywhere...

It was a rough runner. But then stopped.

ECU ends in 018. 1984 car.

No spark so changed distributor, rotor arm and plugs. Spark now good.

Checked fuel pressure all good at 3.5 bar.

It chugs on easystart.

Wiring loom looks like it has not been interferened with.

I could do with information on what I should be getting at ECU plug. I have got some information from BMW 5 forum but not convinced it is right for this version of ECU??

Also ECU pins are not numbered. I believe we read from the top of the pins left to right??

The guide says I should be having +12v DC at 18 and 35 pins which I am not getting. Maybe from other posts I have read from Brucey I should be jumping the Dme relay.

Many thanks in advance, Chris.

[themack]

I jumped the DME today and still got the same

IMG-20181022-WA0007.jpg (131.94 KiB) Viewed 3420 times

readings on the plug of the Motronic ECU.

IMG-20181022-WA0016.jpg (156.18 KiB) Viewed 3420 times

I think I am reading the Ecu plug correctly from left to right from 1-18 at top and 19-35 at bottom.

I am getting 12 Volts with ignition on. On the three Pins which have a dark mark on them.

Numbered 10,19 and 34. I am not convinced this is right and cannot find a good diagram of what voltages I should be getting?

Any help would be appreciated.

The printout I was advised to get online says that I should not be getting those voltages on those pins. However it also asks me to take readings from pins that aren't there!!!

Confused!!

I will also put some pics of the car up on the project page now.

Thanks....

[randall977]

I had job getting mine started - I think in the end it was the Flywheel position sensor - these you can test. Have you by-passed the onboard computer immobiliser?

[Brucey]

if you have spark and fuel pressure the engine should fire on the cold start injector during cranking, even if the main injectors are not working for some reason . So check that the cold start injector system is working; see workshop manual for details, but it is a simple system in which the CSI is only powered in 'crank' and only when the thermotime switch is closed. The latter condition is time/temperature related.

BTW I think your ECU pinouts are correctly identified; as per your photo with the black dots they should be 1-18 (L to R top row) and 19-35 (L to R bottom row)

cheers

[themack]

Hi fellas,

Thanks for advice.

By the way Brucey I am just down the road in Suffolk!

Randall I was thinking it might be pulse generator(?) at the very front of the engine.

I have had a no fire-start problem with one of those before.

I don't know how to by-pass the immoboliser. I will have a look on Forum, I certainly did not put a code in it as I have read about the nightmare stories people have had.

I don't think it is the crank position sensors as it would not chuck on easy start.

So check that the cold start injector system is working; see workshop manual for details, but it is a simple system in which the CSI is only powered in 'crank' and only when the thermotime switch is closed. The latter condition is time/temperature related

Thanks Brucey. I will get a copy of workshop manual. I would imagine there is a link on the forum??? I did not know about the cold start injector system.

By the way my ECU has been repaired. It has a sticker and maybe an etching on it(can't quite remember at the mo!).

Just out of general interest who is the best person to send the ECU's to be checked for faults and repairs?

Many thanks for some usefull leads and tips, Chris.

[Brucey]

crank sensor at the front of the engine is not involved in the normal running of the engine, in any way whatsoever. This is only connected to the diagnostic post and it is only ever used when someone plugs a BMW service computer into the diagnostic port.

pre 6/87 cars have a cold start injector and if that system isn't working the engine won't fire at all easily unless it is already warm.

Not clear from what you say if the engine will or won't fire on easy-start? #

Do you have spark? Spark plus CSI = engine runs briefly, usually.

cheers