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siarach

E34 Not Starting

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Hi Folks, just joined your Forum and as you prob guess I need some help.

I have a 1995 E34 520i that I have owned since 2001 and it has literally never let me down until now. I took it in to the shed to change out the wiper linkage which was a horrible job but never the less completed only to find that I cant get the car started! No Spark, No Fuel, various experts have been looking at it and I seem to be throwing money at various sensors etc to no avail.

I have followed through the various test procedures and came up with very little aprt from a dropped voltage at the Fuel pump (6 Volts).

Any advice on how to move fwd with this will be greatfully accepted.

Regards

John

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Did you start it and stop it very soon after?

 

Sometimes they flood in this situation. A good strong battery and cranking it with your foot on the floor often coaxes them back into life.

 

That said if you definitely have no fuel and no spark perhaps an old immobiliser or you've dislodged something doing the wiper rack?

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Duncan,

Dislodging something seems to be possible but i dont know what?

I had to take the ebox out and disconnet the ECU but it all went together with no hitch.

 

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Possibly a dry joint in the ecu or break in the loom that was disturbed when moved?

 

The fact you have no spark and no fuel would suggest a common earth or something?

 

Was an earth disconnected?

 

Start simple i would suggest.

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Checked the Relays and all fine.

Pic 125 what is this Term/Junction? What Voltage should I expect with the ign off/ign on?

Pic 126 Green relay tested ok and I assume its the Fuel Pump Relay?

Pic 127 White relay tested ok and I assume its the DME Relay?

 

I am desperate! I have been at this now for a couple of weeks and haemorraging money with "experts" looking at it!!

 

Any advice?

Regards

John

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Late to the party but it sounds like you are struggling. If you think the problem is within the e-box, check the following:

That you have connected the cables to the B+ terminal if you removed them. 

(The one half way along the bulk head. It has a big + on the plastic cover)

That you have battery voltage at the terminal in your pic and at pin 30 in each of the relays.

 

Pin 30 of the relays is a permanent live so should read battery voltage. If you wanted to jumper your fuel pump relay, you would just connect that pin to pin 87. No key is needed. It will run forever - or until the battery goes flat. BUT the fuel pump will only receive power if the engine is cranking or running when operated normally.

 

Pin 85 will also have battery voltage with the ignition on. Pin 86 is grounded by the DME and it is this that acts as a switch (with pin 85) to connect pins 30 and 87 together . So you need to check if that pin is getting grounded

 

Hope that makes sense and helps rule out a few things

 

 

Edited by whiskychaser

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Thanks this info is invaluable.

Just carried out some checks and I have Batt Volts 12.8 at the B+ Term but at the Fuel p/p relay I am getting 4V?? Anybody have any ideas where I can be losing it?? This clearly is the root of my problem.

in fact I am only getting 4V in the whole harness that stretches across from the B+ term to the ebox??

 

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The red wire that runs from the B+ terminal to the e-box is pretty thick. Are you able to identify it? If so, disconnect it at the e-box end, put your meter red probe on it and the black one on ground. (The nuts on top of the shock turret are usually a good ground) You should get battery voltage but that will also rule out if something in the e-box is dragging it down.

 

If you only get 4v, disconnect it at the B+ terminal as well and ohm the cable out. It is possible that the round rings on that cable look fine but they are not making a connection

 

PS. The car is a manual isn't it?

Edited by whiskychaser

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OK, this info has been good and this is what I have found.

My ebox is fed from the battery underneath the rear seat, a wire is clipped in to trunking along the inside of the O/S sill, i tested the wire and I was getting 12V as it left the Batt connection but 12 inches along I was only getting 4V?? Stripped it back to find what looks to me like a fusible link? I have enclosed a pic. Does anybody know the name of this or what value it has or what can I replace it with?

I have carried out a continuity test and its dead.

I have resisted bypassing it just in case I cause any damage but if I did I would then get 12V to my ebox and am sure the car will start.

 

And yes its a manual

PHOTO-2019-08-15-11-59-44.jpg

Edited by siarach

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If it were an auto, you would be getting 'trans program' in the cluster or, as you have a 520i, the gear symbol. That is because the TCM needs at least 9V. If it doesn't get that, you get the warning and it goes in limp mode.

 

The fusible link will be 80amp and normally supplies power to the fuse boxes.  A crack is quite common. It is very hard to see but the result is reduced or no voltage. In which case, nothing much is going to work. I think you might find it difficult to get an exact replacement but could try something like this:

https://www.ebay.co.uk/itm/1-Heavy-Duty-Inline-Fuse-Holder-with-80amp-strip-fuse-/391479471730

 

If you have a low value fuse in your tool box, you could always connect that across the fusible link to test if you now get battery voltage at pin 30 of the relays. 

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