Urgent help, fuel pump relay????

[charlE30]

It won't start, new 80amp batt full tank of fuel and has always started on the dot, never had any problem starting. The engine turns over easily but nothing happens, she dosen't fire.. Could the fuel pump relay have failed (is there any way to test)? or the OBC code function cut in even though I never use it and the OBC display dosen't say code just the temp Everthing electrical is working as it should, the engine just won't fire up. Please help, someone out there must have had this happen to them??? I have checked fuses 9, 10, 21.

[Andy335Touring]

Has she got a spark and can you hear the fuel pump ?

[Andy325i]

Hi Mate, have you got a spark? have you got fuel at the fuel rail?

The relays are quiet common. (The white one)

Guy over the road had that very problem.
He was well impressed when I knew what it was straight away lol

they are about Ԛ£7 or Ԛ£8 from Euro Car parts
Always handy to keep a spare

Kind regards

Andy

[charlE30]

Don't know if she's sparking (how do you tell??) and have never heard the fuel pump before (could be going deaf ). It feels like there's no fuel getting to the rail, turns over nicely...

[Andy335Touring]

To tell that you've got a spark,remove one spark plug,reconect the HT leed and rest the plug on your rocker cover or a metalic surface,then when you try to start your car look for a spark.If your engine trys to fire up when you do this turn it off.

The fuel pump can usualy be heard by your rear drivers side wheel,get some one to turn the key to the position before the starter kicks in whilst you listen by the wheel.

The other way to check you've got fuel at the rail is to disconect the fuel line at the fuel rail,make sure you hold a rag over the pipe as you pull it off to catch the fuel that will spurt out.Then get a container and put the end of pipe in it and flick your ignition on for a second or two.

I don't know your mechanical experiance but if you feel unsure what to do ask again or try to get friend to look at it ?

[Brianmoooore]

Fuel pump only runs for a couple of seconds after switching the ignition on, then stops untill the engine is turning over.
Simple way of taking the fuel pump relay and it's control system out of the equation, is to place a temporary wire link between pins 30 and 87 of the fuel pump relay socket.
Found some yellow "relays" in a scrap E34 fusebox the other day,with only two pins. Turns out they are pin 30 to 87 shorting links. Will be carrying one of these inside each of my E30s fuseboxes from now on. Could be usefull one night at the side of a motorway.

[Andy335Touring]

I've seen those two pin relays before and wondered what they were for.

I might still have some from my old E34 ?

[charlE30]

Cheers for the advise I'll check it out properly this afternoon

[charlE30]

Well I've got a good spark, made a fused link wire and jumped 30 & 87 to bypass the relay and nothing happened. Have even disconected my OBC just to make sure it's not interfering, tomorrow I'll disconnect a fuel line to see if fuel is flowing.. I've got a nasty feeling that my fuel pump has gone, will do a few more tests on the pump with my multimeter in the morning but it looks like GSF are going to be getting a load of my hard earned cash .

[charlE30]

I removed fuel line and jumped pins 30 & 87 and no fuel came through, have checked pin 30 with ground and there is voltage. Connected mutlimeter to pins 86 & 85 turned ignition and voltage was present. I disconnected fuel pump and checked for voltage with pin 30/87 linked and 12.4v showed up. So I'm assuming it definetly is the fuel pump unless anyone else has any suggestions. .....

[Brianmoooore]

Probably is dud fuel pump, bet checking voltages on disconnected plugs, etc., with a multimeter can be meaningless. A high resistance joint somewhere in the circuit would still result in a meter reading of 12V. Best method of testing is with a 21W 12V lamp.
A lamp like this, with two pieces of wire ending in croc. clips , and a long piece of wire with a big croc. clip to fit the battery and an inline 30A fuse are two of the most used electrical fault finding items in my toolkit.

[Guest]

Hi

This has just happend to me. Car just cut out. It was the fuel pump. I have been told that E30 are prone to them failing. Simple job to replace.
Second hand ones are about Ԛ£25 - Ԛ£40 and new ones are between Ԛ£120- Ԛ£155.

I managed to get a good second hand one for Ԛ£35 and everything is back to normal.

[A1BMW325iSport]

have u got the in tank fuel pump? as i got both types if you need 1.

Matt

[breitlingboy]

Matt,

I maybe after an in tank pump.
How much are you after for it?

Cheers

[Brianmoooore]

E30 fuel pumps aren't unreliable. The same basic Bosch pump is found in lots of manufactuers fuel tanks, but in most cases the car around the fuel tank will have expired long before the kind of mileages and ages that E30s reach.

[Brianmoooore]

For all you looking for second hand pumps.
There is a difference between four cylinder and six cylinder pumps. The basic pump is the same and can be swapped between the two, but the metalwork around the pump has a difference.

[Andy335Touring]

For all you looking for second hand pumps.
There is a difference between four cylinder and six cylinder pumps. The basic pump is the same and can be swapped between the two, but the metalwork around the pump has a difference.

Is that because the tanks bigger on the six's ?

[Brianmoooore]

No, it's to do with the fuel retun pipe.

[Andy335Touring]

Ah right,cheers

[A1BMW325iSport]

but if your a wizard at soldering you can fit the pump into correct frame.

[A1BMW325iSport]

breitlingboy - PM sent