Fuel Pump

[ButtonIt]

So the search function on here still doesn't work then?

So, after my Chim 400 failing it's MOT yesterday on sidelight bulb (I'm sure it was working), numberplate bulbs (actually they were working, but the tester didn't realise it was backlit...) and exhaust gasket leaking (the real reason he failed it) I drove the 30 miles back to my house only to break down on the M27

Now, I thought I might have run out of petrol. I also thought the alternator might have packed up. Either way, a local recovery company towed it the last 15 miles and when I got home I filled it with 20 litres of v-power from my big can and stuck my donor battery on it. The fuel pump wouldn't prime. Nothing, not a sausage. Ignition lights all come on and the engine can turn, but no tell-tale whine from the back.

Is it possible the fuel-pump relay has gone with my battery being so flat? The battery is new (2 years old) but it ran flat over the last couple of months of not being used so I've been jump starting from a big leisure battery and only doing shortish distances, probably not enough to get a full charge in. Or, is it possible that the fuel pump packing up caused me to break down? Or, having ran out of fuel has caused the pump to pack up? My fuel guage is temperamental at the best of times and I'm not sure exactly how much was in there.

The annoying thing was I was only three miles from the petrol station where I planned to fill up anyway.

Bloody cars, another thing to add to my ever growing list of things to do. The trouble is all the mechanical things are eating into my cosmetic budget (needs new dash and hood). If only I didn't love it so much

[gavgavgav]

As you have power, the usual suspects would be immobiliser, relay, wiring on pump end and the pump itself. Checking the voltage at the pump terminals is the best place to start, and it's free to do if you already have a voltmeter.

If it does have voltage, check the earthing for the pump.

[ButtonIt]

How's the best way of getting to the pump?

[gavgavgav]

Just take the left read wheel off, you will see the pump mounted between the lugs of the bottom wishbone.

[Harrytsg]

As well as running through the above , the fuel pump feed runs through the inertia switch. For the sake of a minute to reset its worth doing.
Under dash on passenger side, drop the 'pouch' and its facing towards the engine, just push the button.

[ButtonIt]

Great, thanks guys. Can I ask what the inertia switch does?

[plushuit]

ButtonIt said:

Great, thanks guys. Can I ask what the inertia switch does?

In the case of an accident, it cuts the power to the pump when it senses a shock or great vibration. This prevents a broken fuel line from spraying the accidented vehicle with fuel at high pressure. In practice, they can occasionally open when the car hits a signifcant bump or a very bad road. They have a button on them for a reset.

[daveparry]

Was your car problem the fuel pump? what were the symptoms, misfire or just lack of throttle response?

[ButtonIt]

It turned out to be the relay that goes into the blue plug beside the battery box. I put a new one in and sure enough the fuel pump started priming and the thing sprang into life. Now I have much different issues with a horrible battery drain.

[daveparry]

I too have a bloody battery drain problem, mine wont hold a charge for more that 3 days befor the alarm starts sounding, if i put my Ctek on it the charger goes into alarm mode which according to the makers means that the charger is not able to keep up with the drain!!! ps it is a new battery of 720 cranking amps!

[ButtonIt]

I've just found the cause of my battery drain... the relay I replaced. If it's not one thing it's another

[NOTAFINGA]

Are you sure its the correct type ? As the Bosch/LR one's are bespoke for that job.

[ButtonIt]

Probably not, it's a £3.99 one from an autofactor. It has fixed my fuel pump, ie. it's now supplying voltage to the pump whereas before it wasn't, but now it's CONSTANTLY supplying voltage even with ignition off. I was having a constant 2 amp drain on my battery.

[gavgavgav]

there is a bosch on ebay if you want a proper one.

[NOTAFINGA]

ButtonIt said:

Probably not, it's a £3.99 one from an autofactor. It has fixed my fuel pump, ie. it's now supplying voltage to the pump whereas before it wasn't, but now it's CONSTANTLY supplying voltage even with ignition off. I was having a constant 2 amp drain on my battery.

Yep you need to junk that and fit the correct relay http://www.rimmerbros.co.uk/Item--i-AFU2913LP

[tonys]

The pump relay is an electronic one,which switches off the pump automatically whereas a normal one will energise the pump and thus flatten the battery.

Bosch part nos. in this thread:

http://www.pistonheads.co.uk/gassing/topic.asp?h=0...

[NOTAFINGA]

tonys said:

The pump relay is an electronic one,which switches off the pump automatically whereas a normal one will energise the pump and thus flatten the battery.

Bosch part nos. in this thread:

http://www.pistonheads.co.uk/gassing/topic.asp?h=0...

Euro car parts 450110050
BMW Part 12631729 I can vouch for the ECP pt number as BMW replacment parts (yes early Beemers use em too) and are good quality as I originally posted this up on the net many years ago as a TVR equivalent part

[ButtonIt]

As always, PH comes to my rescue!! Cheers guys

[EGB]

For garaging short/long term fit a battery cut off switch. £10. Also, helps to reset the ECU.

Edited by EGB on Friday 9th November 10:00

[NOTAFINGA]

Just thought I would update this thread with alternative ECU/Fuel pump/02 heater relay's BMW uses same spec unit, found this knocking around on my work PC so thought it may help.
BMW models
1990 - 1998 318ic
1990 - 1997 318is
1995 - 1999 318ti
1986 - 1988 325
1986 - 1987 325e
1986 - 1987 325es
1987 - 1995 325i
1987 - 1995 325ic
1987 - 1995 325is
1988 - 1991 325ix
1988 - 1995 525i
1992 - 1996 525it
1993 - 1995 530i
1993 - 1995 530it
1988 - 1993 535i
1993 - 1995 540i
1987 - 1992 735i
1988 - 1992 735il
1992 - 1995 740i
1992 - 1994 740il
1987 - 1994 750il
1994 - 1997 840ci
1993 - 1997 850ci
1994 - 1995 850csi
1990 - 1992 850i
1990 - 1993 M5

Equivalent #: 12631729004 & SIEMENS V23134 C52-X90 & Bosch 0 332 019 109

Edited by NOTAFINGA on Thursday 15th November 15:45