95 325i Fuel problem

monk2 · 03-05-2008, 06:05 AM

Hello having major problem with my e36 325i.

Moved it out of drive to allow my girlfriends car out and when I went to start it the engine is just turning over.

It appears the fuel pump is not running when ignition is switched to on or start. The fuel pump fuse has no voltage. I have replaced fuel pump relay and dme relay no change.

I have taken a jumper wire from another live fuse to the fuel pump fuse and the pump runs so its fine and wiring is good. When I do this i can hear fuel going through the rail.

I've had all the sparkplugs out and they are sparking, Also removed cam cover to check timing chain or if valve had stuck but all fine.

Replaced Cam sensor yesterday after reading on here that it may be the problem but still the same!

It seems that even with the pump hotwired on the injectors are not allowing fuel to the engine.

I don't have access to wiring manual so don't know the control proccess for the fuel pump/injectors.

Does anyone have any ideas?

Any help appreciated!!

Jeron · Jeron's Garage

A bad crank sensor will prevent the fuel pump from running and will prevent starting in general.

Will it start if you power the fuel pump externally?

monk2 · 03-05-2008, 08:19 AM

No powering the fuel pump doesn't seem to make any difference. I can hear the pump and it sounds like there is fuel going through the injector rail but it doesn't start. Just turns over.

Should the injectors make an audible click when opening and closing?

I have managed to source a suitable donor car in a local breakers yard so will try the crank sensor next..

Jeron · Jeron's Garage

I dont think you could easily hear the injectors during startup, maybe with a screwdriver to the ear though. Can you smell fuel at the exhaust? At the plugs wet with fuel?

Crank sensor is what I would do next.

monk2 · 03-05-2008, 12:47 PM

Thanks I'll give it a shot!

I'll post the results for future reference.

monk2 · 03-19-2008, 06:04 AM

After much delay due to weather work etc..

New cranksensor fitted still nil fix

Have now also tried another DME but still nothing!

The car will start if starting fluid is sprayed down throttle but no fuel is coming through the injectors.

What else controls the injector pulses? And what controls the fuel pump? Is there a common link that I have not tried?

Also should the injectors be recieving 12V at their connectors or is it stepped down?

Lots of questions i'm afraid

These symptoms seem quite common on here. Are there known faults?

Jeron · Jeron's Garage

You've established it wont start if you power the pump, but it does start with starter fluid.

bad pump
fuel filter
fuel pressure regulator
injectors not firing

My next suggestion is to test fuel volume and pressure.

As far as injector firing the info is in the Bentley but I recall the items to be crank sensor, relay, DME.

monk2 · 03-19-2008, 08:29 AM

Many thanks! The investigation will continue...

monk2 · 03-20-2008, 03:01 AM

Looking back through the forum I came across a thread by zarus from october last year. His problem appears to be identical!
Jeron posted some wiring schematics which show the engine management system.

Unfortunately the diagrams are a little blurred and I can't really make out some of the detail

.

But it appears that 1995 model cars have a solid state time delay relay in the system which appears to control both the fuel pump and the injectors.
Does anyone know where abouts this is positioned so that I can test it?

there was no conclusion to zaurus problem unfortunately so no easy fix!

monk2 · 03-23-2008, 02:56 PM

Now confirmed injectors not getting voltage and fuel pump relay not being energised..