Non Starting.

Hi Norbert ,I now have a bulb holder for the H4 bulb it has three cables attached Red of course to the Red pin on the volt meter which of the other cables do I attach the other volt meter point.? Also with the wiring out of the ECU  when I test does the contact to the wires have to be done quickly ie just a quick contact to the wires or is it safe ie no fear of damage to the system? I hope the bulb comes today..Thank you ,have a good weekend, Regards Nigel.

Hi Nigel,
don't care about the cable colours - connect the bulb as I described before and connect the voltmeter towards 24 (injector-power-line) and 11 (ground) with the ECU disconnected.
There will be some current (about 5 A) and the bulb will get very hot... but you will not destroy anything that has been o.k. before.
This is a load-test and I think, you will not measure the voltage that is needed to run the injector-amplifier.

I didn't think you would order a bulb but just take one out of the car or use a spare.

Regards
Norbert

Hi Norbert, So to be clear I just connect for a few seconds  without taking any readings . This is just to try and wake up the injector part of the ECU.?  Then reconnect the ECU and try pin 24 again.?  Regards Nigel.

No.
Connect the bulb and the Voltmeter and read out the Voltage with the ECU disconnected.
This is to check out the power source for the ECU.

Regards
Norbert

Hi Norbert,Just checked with the bulb .It did not light up.Re connected my original,ECU and I have 12.75 on pin 24. No sound from the pump relay or pump.Both which are new or newish.! I guess I will have to try the same with my spare ECU .which I know was working the last time I tried it on my driveway about 5/6 years ago..Regards Nigel.

Hi Nigel,
what Voltage did you measure with the bulb connected?
What you report is not possible.
The power comes from the relays, not from the ECU.
There has to be power with ignition on - with or without the ECU.

You said you checked anything around the relays. I think there is anything faulty there.
Maybe a cable, a contact or one or both relays.

When you switch ignition on, you should hear the main relays click - and the pump relays, too. The pump relays only with the ECU connected - but the main relays with or without the ECU.
Without the ECU you should have more than 12 Volts.

You can bridge the relays by making a connection between relays-pin 30/51 and 87.
But disconnect the battery before you do this - you have permanent power on pin 30.
Then you could do the test with the bulb again.

It makes no sense to test another ECU without having verified the power supply.

Regards
Norbert

Hi Norbert, I think I'm getting incorrect readings owing to the voltage meter pins beings a bit too thick I've ordered some needle thin ones ,as im finding it hard to make good contacts at the loom pin contacts as they are slightly set inside. .Sorry struggling amateur..Regards Nigel.

Hi Norbert ,ECU connected, ignition on,both the main relay and fuel pump relay click,but no sound from the fuel pump.As I said I will do the bulb test once I have the thin meter probs this week. Thanks ,best Nigel.

Hi Nigel,
you have to find out the reason for the fuel-pump-failure.
Could be the fuse in the little black box near the relays, a non-contacting relay, the wiring or the pump.

Regards
Norbert

Hi Norbert,The fuse is new  the relay is new ,I've also swopped it for a 2 year relay and the pump is as new .Last time I checked in this situation there was no power to the pump at the pump terminals. I've tried swapping the main relay .no joy. Could I run a cable outside the car to the live side of the pump and a seperate cable to an earth point.from the pump .If so which terminal at the relay should I connect to.? I take it you don't think this is a ECU issue ? I've seen as mentioned before two green and white cables from the relay to the wheel arch and inturn one for sure goes to the pump .Somewhere along the cable it must be split as at the plug end pump connection is a brown and the green and  white cable .At the pump relay one of these cables comes from 87 the other 30/ 51.both green and white. Regards Nigel. As the pump activated when I grounded the test light to pin 85, the lead must be OK from the relay to the pump.! Could it be a poor earth for the pump? If I connected a cable at the pump connection on the negative side to ground would this prove it? 

Hi Nigel,
pin 87 of the FPR is the point for the positive wire. The negative connector of the pump is ground -you could connect it to one of the brown cables, pin 11 or chassis ground to test the function with good ground.

I saw the cable harness is split (I think at the firewall) with a (I think big) connector plug.
Is anything o.k. there?

There is a split point (welded) inside the car (I think, it will be near the ECU). This is essential for both the lines 24 (injector-power) and 86 of the pump relay.
I have an electrical plan without the colours only, but I think this is the point where you find answers for your colour-questions... This line also could be faulty. It's also connected in the connector-plug.

The plan I have won't help you because it is in German and the additive notices there are essential.
Do you have an English plan?
I didn't find one, but I know both Bosch and BMW published such plans.

Regards
Norbert

Hi Norbert ,Thank you for that ,I will try and look  at the cables for faults ,there is a triple plastic clear blocks fitted to my top servo ,I've take this apart to have a visual check of the wires they all appear ok.Yes I have a BMW wiring diagram, but I'm getting out of my depth with the electrics.A friend is paying me a visit next month and he has good knowledge like you of this system, so I hope between you both I will get to the bottom of the problem..The weather is horrible here so not missing much driving.Regards Nigel

Hi Norbert ,Thank you for that ,I will try and look  at the cables for faults ,there is a triple plastic clear blocks fitted to my top servo ,I've take this apart to have a visual check of the wires they all appear ok.Yes I have a BMW wiring diagram, but I'm getting out of my depth with the electrics.A friend is paying me a visit next month and he has good knowledge like you of this system, so I hope between you both I will get to the bottom of the problem..The weather is horrible here so not missing much driving.Regards Nigel

Hi Norbert,I tried connecting a seperate ground wire from the pump connector under the car to the chassis, No sound from the pump.I then removed the ECU wiring and connected my volt meter with two needle tips and the bulb taped to the meter ends and the bulb lit up and was showing around 10.5 V this maybe because of my poor connections. Then put everything back together now ignition on main relay clicks but the pump relay is quiet .I give up .How can I send a picture ? I cant figure out the icons above this writing..I want to take from my libarary ..Regards Nigel.

Hi Nigel,
you have to reduce pictures to insert them.
There are special ads for mobiles to do this, under Windows I use the free image resizer.

You can add Attachments (like pictures or other files) below the text field.

Regards
Norbert

Thanks Norbert, Quick question do you think the voltage could be OK? Does this prove the ECU s are probably OK? Best Nigel.

10,5 Volts are not sufficient for a proper operation, but should not lead to a total misfunction.
All Voltages, cables, sensors and so on have to be checked before one could  say anything about the ECU function.

Regards
Norbert

Hi Norbert, OK thanks .Regards Nigel.

Hi Norbert ,How can my ignition switch be tested for being faulty ? Could I test the cable to the fuel pump fuse and to ground with the ignition on .? This fuse is part of the main fuse board. With a test light. I'm suspecting the problem is intermittent, as after sometimes the pump activates. Also I've not seen that my electric aerial does not come up when I turn on the ignition ,whether this is the ignition switch or the aerial at fault !. Regards Nigel

Hi Nigel,
the aerial is normally activated by the radio, not by the ignition switch.
Maybe the radio itself is powered by ignition switch...
The fuel pump relay gets the power from fuse 7 (coupé) or fuse 11 (sedan).
You should check the voltage there.
 
Regards
Norbert