E34 Won't Start - BMW Forum

bpearson · 09-16-2008, 11:00 AM

I am trying to help my friend out with his E34. The car was running great one day and then the next day it just would not start. I have tested the relay and it is working, but I am not getting power to the fuse 15amp#23 if I hot wire the fuse the fuel pump runs, but the car will still not start. If I use starter fluid, it will start up for and run for a few seconds. I have tried tracking the power from the relay to the fuse, but cannot find any problems with the harness I am ready to pull the fuse box and trace it back to the relay.

Please help...

Thanks,
Ben Pearson

marti5 · 09-16-2008, 11:13 AM

Its defintely the fuel system,as when you put starter fluid in its runnnig on that alone and not petrol, so I would say you have a circuit break to the pump, which maybe a bad earth. As for no power at the fuse, bad contact in the fuse holder.

bpearson · 09-16-2008, 03:12 PM

Why would the car not run with the pump hot wired? any ideas?

chinonca · 09-16-2008, 03:23 PM

Quote:

Originally Posted by bpearson

Why would the car not run with the pump hot wired? any ideas?

Is the pump pumping fuel???

bpearson · 09-16-2008, 03:37 PM

yes the pump is pumping. I am going to put it on the fuel pressure gauge tonight.

chinonca · 09-16-2008, 03:43 PM

Possibly clogged filter??

marti5 · 09-16-2008, 03:58 PM

clogged filter! good point CHINONCA, may well be, remove the pipe in the engine bay (fuel) turn on ignition, if nothing comes out, blocked filter!! if not the diaphragm in the pump is shot, new pump required.

chinonca · 09-16-2008, 04:01 PM

Yup that simple to diagnose!!!

bpearson · 09-16-2008, 04:40 PM

Well I hope it is clogged. I am having a hard time with thinking through the electrical issue. I do not know were the power went from the relay to the fuse. Any ideas why there is no power at the fuse?

chinonca · 09-16-2008, 05:04 PM

Quote:

Originally Posted by bpearson

Well I hope it is clogged. I am having a hard time with thinking through the electrical issue. I do not know were the power went from the relay to the fuse. Any ideas why there is no power at the fuse?

Power flows from the fuse to the relay then the fuel pump. It could be an ignition switch problem too.

marti5 · 09-16-2008, 05:32 PM

As said ,ign switch prob???, I think ign would be intermitent, but may be bad earth !, I will stick with my 1st diagnosis bad electrical contacts as over night when turned off switches and pumps dont just say stop working, so im 100% electrical bad contacts.

bpearson · 09-16-2008, 06:03 PM

Quote:

Originally Posted by marti5

As said ,ign switch prob???, I think ign would be intermitent, but may be bad earth !, I will stick with my 1st diagnosis bad electrical contacts as over night when turned off switches and pumps dont just say stop working, so im 100% electrical bad contacts.

Thanks I will tell you how it goes...

bpearson · 09-17-2008, 01:03 AM

well I have fuel pressure 51 psi. Now I guess I am hunting down the electrical. the fuel pump relay also powers the injectors? maybe i am not getting power to the injectors? any ideas?

fucntone · 09-17-2008, 06:43 AM

Quote:

Originally Posted by chinonca

Power flows from the fuse to the relay then the fuel pump. It could be an ignition switch problem too.

i've been having a problem getting my car th start as well.. when i turn the key everything comes on, but the starter won't turn over... i had the starter tested and it's good.. i jumpered it at the starter with a screwdriver and it starts... think the ignition is the problem for me?

marti5 · 09-17-2008, 08:26 AM

Quote:

Originally Posted by fucntone

i've been having a problem getting my car th start as well.. when i turn the key everything comes on, but the starter won't turn over... i had the starter tested and it's good.. i jumpered it at the starter with a screwdriver and it starts... think the ignition is the problem for me?

Could be 1 of 3

1, Ingnition switch

2, starter motor solonoid

3, the most likely is a bad earth to-from the starter