fuel pump problem

Post Sat Oct 28, 2006 1:57 pm

hi everyone. bought my first bmw about a month ago. a tidy 92 325i cab. won't start this morning! suspect the fuel pump has packed up as i can't hear it whirring when i turn the ignition. is the relay on the inner wing? can i swap it with another on the car to eliminate that? if its not that is there anything else i should look at before swapping the pump? and how difficult a job is that? hope someone can help!

Post Sat Oct 28, 2006 2:11 pm

Fuel pump relay can be swapped with most of the similar looking relays, but the ECU doesn't turn the pump on via the relay if it doesn't sense the engine is turning.
Best thing to do, is pull out the relay and link pins 30 and 87 of its socket with a piece of wire. This should make the pump run continuously, ignition on or off.
If you can't hear the pump with this link in place check fuse 11.
If the pump does run, try to start the engine.
Don't forget to remove the link when you finish.

Post Sat Oct 28, 2006 2:25 pm

thanks for the quick reply! fuel pump relay is the one next to the white one? i'm sure i've heard the pump running in the past with just the ignition on. should it not do that until i turn the engine over? thanks for what you've told me so far. gonna nip out and try that piece of wire

Post Sat Oct 28, 2006 2:56 pm

tried bridging pins 30 and 87. no joy. swapped fuse 11. no good either. i've got 12 volts at pin 30 so would i be right in assuming the pump is dead?

Post Sat Oct 28, 2006 3:59 pm

brandnew wrote:tried bridging pins 30 and 87. no joy. swapped fuse 11. no good either. i've got 12 volts at pin 30 so would i be right in assuming the pump is dead?

Looking that way, assuming you've got the right relay.
Remove the back seat cushion and take off the oval inspection cover underneath. You'll be able to hear it then if it's running.
Pull the connector off the pump and connect it to a 12V bulb. The bulb should light with the wire link in place, or when cranking the engine.
Good smack on the top of the pump with the end of a long 1/2" socket extension bar often brings it back to temporary life.

Post Sun Oct 29, 2006 2:00 pm

Had a look under the back seat today and unplugged the wires. have power at that end so plugged it back in and hey presto pump is working! sprayed it with contact cleaner but flattened the battery now. think i should be back in business after i've charged it though. thanks for your help. you seem to be the man in the know with all things E30! by the way is gsf short for german swedish french parts supplier? they seem to pop up on the forum quite a bit. anywhere else good for cheap spares?

Post Sun Oct 29, 2006 2:07 pm

euro car parts is much the same as gsf although sometimes the bmw main dealer is surprisingly cheap for parts so always check there first.you are correct with regards to brianmoooore though,if he doesnt know then no one does

Post Sun Oct 29, 2006 3:55 pm

Duff fuel pumps are like that. I very much doubt if it's a connector problem.
You disturbed it just enough to get it going again. It may be OK for weeks now, but it'll stop on you again, when it happens to come o a stop in exactly the same place.
Start the search for a fresh one.

Post Tue Oct 31, 2006 1:58 pm

Thanks for the warning brian. been ok since the other day. knowing the problem is half the battle. there is a branch of gsf not far from me so if it packs up for good i can get one from there. prices seem reasonable..ish!