WINDZ,

Thanks for the diagrams - brilliant! Wish I had a full manual! I am persuing a slightly different route at the moment however.

O.K, it would appear that the pump located inside the fuel tank isn't working! At this stage I would love it if you said 'oh yes, that would be fuse No. xx, but I (think I) have checked the fuses (unless there are some hidden ones lurking around somewhere?)
Again, I assume this pump failure could be ECU related, but for the time being I am investigating the fuel pump itself. Anyway, there are 2 wires running down to the pump itself - a purple and a brown. Which of these is +?
If I can test the pump by putting power directly to it I will know for sure if the pump is working. If not, I know where there is one for 40 quid. If it does work, then I will have to delve deeper. Do you happen to have a diagram showing how I get the pump out?

I really appreciate the time you have given to helping me out! I am  determined to get to the bottom of this as I love my 525 and am sure it will go for a good while yet - the engine still runs perfectly - the suspension has needed some work over the last 12 months, but I am confident with all these jobs and have already replaced the majority of it. I get married in a few weeks, so cash is really tight, otherwise I would have got an auto electrician out by now.

Thanks, Tim.

sandracer wrote:

Anyway, there are 2 wires running down to the pump itself - a purple and a brown. Which of these is +?

usually on german cars they use brown as the earth/ground


_________________
W I N D Z
" Once is enough, Twice is too much, Thrice is a disaster. "

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you needed to check the relay too.

the number (2) os for the fuel pump relay

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_________________
W I N D Z
" Once is enough, Twice is too much, Thrice is a disaster. "

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try to bridge terminals 30 and 87 then ignition on.


_________________
W I N D Z
" Once is enough, Twice is too much, Thrice is a disaster. "

www.M-BenzForum.com

You STAR!

Just bridged the terminals as suggested and lo and behold - the pump is working fine/dash lights extinguished! I assume that the relay must be knackered!

I guess the BMW garage will be my next port of call!

Thank you ever so much for your help with this matter! I am so pleased!

Prepare however for my next installation - 'The dodgy instrument cluster'.

Kind regards,

Tim

sandracer wrote:

You STAR!

Just bridged the terminals as suggested and lo and behold - the pump is working fine/dash lights extinguished! I assume that the relay must be knackered!

I guess the BMW garage will be my next port of call!

it will be much cheaper if you replace the relay first and if still won't work then it's time to call the BMW stealership.


_________________
W I N D Z
" Once is enough, Twice is too much, Thrice is a disaster. "

www.M-BenzForum.com

sandracer wrote:

Thank you ever so much for your help with this matter! I am so pleased!

Prepare however for my next installation - 'The dodgy instrument cluster'.

no problem, just resolve the relay problem first and we'll start with the instrument cluster.


_________________
W I N D Z
" Once is enough, Twice is too much, Thrice is a disaster. "

www.M-BenzForum.com

OK - My car is running again! I started it up with the terminals bridged. I was planning on nipping down to the local breakers tomorrow morning to pick up a replacement relay, but I slotted the old relay back in and, lo and behold - it worked!!??!! Car runs fine!

Hmmmm, I can only assume the initial problem must have been 'damp' related. To be honest, it did seem a little damp inside the box that houses the relay, and, I did notice some moisture around the bottom of the flasher relay (also playing up). Not surprising really as I live in an area that has had the worst flooding in the UK recently, not to mention the non-stop rain we are still experiencing.

I'm a bit dubious about this miracle cure, but still glad that it runs! Might pick up a spare relay anyway!

Is there anything inside that fuse/relay box that could affect my instrument cluster? Both the tacho and speedometer give wild readings, ie, 150mph when I am doing 40, and almost always in the red-line! The temp and fuel guages seem ok as is the odometer - it's just the clocks that are out!

Cheers!

Same problem again! 3 days later I had to be recovered by a tow truck due to the same non starting problem!

What is stopping me from taking power directly to the fuel pump from the battery via a switch?

Whatever the problem is, it seems to be stopping power from getting  to the fuel pump. I know my idea sounds like a bodge, but if it gets it running for a short while then I will be happy. Its impossible to survive without my car!!!

fuse still okay???

did you replace the relay already???

is the relay box has been ingressed by water before???

did you check the wiring from the relay box going to the fuel pump???


_________________
W I N D Z
" Once is enough, Twice is too much, Thrice is a disaster. "

www.M-BenzForum.com

Yes, the fuse is ok.

I didn't replace the relay as it still seemed to work. However, there are several of these relays on my car and I have tried these to no avail.

I haven't traced the wiring back as yet - I don't have a diagram and, to be honest, don't feel that confident with wiring harnesses.

Mechanics - YES, electrics - NO.

I guess I will have to get an auto electrician on the case, but those I have spoken to don't think a diagnostic machine will show where the fault lies due to the age of the vehicle.

on most cases a relay problem won't register on the scanner. i'll try to provide the wiring diagram later. it's easy to check the wirings... voltage, continuity, short to + and short to -. that's all you need to check but must have VOM multi tester.


_________________
W I N D Z
" Once is enough, Twice is too much, Thrice is a disaster. "

www.M-BenzForum.com

OK,

Got an auto electrician to check it out and it appears the ECU has failed! Mr. BMW wants 1420 squeakers for a replacement, so that's out of the question!
However, I have managed to fool the car into starting by taking a live direct to 'a' relay. Problem is, the car is still in 'Limp mode'! It runs but feels like the turbo has been removed - so it's impossible to accelerate at a decent pace! Other than that the engine is as sweet as ever.
Is it possible to bypass this problem at all? It's due it's M.O.T, and I just don't want to spend cashola on something with the power delivery of a micra.
I have also tried to source a second hand ECU - but to no avail!
Please tell me I can get round this engine management restriction somehow!!
Cheers,
Tim