280i fuel pump and relay?

[hallsie]

Has anyone got a physical pic of the fuel pump and the other bits that are under there?

And where the bloody hell is the fuel pump relay on an early 280 FHC with all black wiring? I cant seem to see anything under the bonnet!

Had a bit of a funny one today, drove her out of the garage onto the drive to sort out the new stripes and refit the new drivers door surround.
Started fine and I could hear the fuel pump fire up no problems.
Thought after about 2 hours of messing and preening (the car, not me) that it would be rude not to have a little blast out, so once again, ignition on, fule pump started and fired up, only to get to the end of the drive and stall.....
She started again after a few seconds for about 1 second but obviously only with the fuel that had managed to gravitate through the system.

There is now no fuel pump whiring and unless its turned into a super quiet unit Im assuming that the pump has either popped a fuse, killed a relay, or dropped an earth!!
It was kind of damp outside, but there is a fairly heavy gauge earth ran straight from the battery to the pump so I think I can rule the dropped earth off the list.

I havent fiddled with any wiring while doing the door frame.

Any ideas??

Stu

[mrzigazaga]

Hi Mate..I think our two cars are completely different..My relay board is under the glovebox and there are two fuel pump relays on it..On mine there is a green plug on the side of the metering head which when un-plugged creates a feed from the ignition to the pump and by-passes the relay..If you can do it with yours dont leave your ignition on too long if the car is not running as it could over work the pump...Sorry i cant help anymore than that as i was fortunate to have coloured wire...Mark

[Mr Tank]

hallsie

See atttached pic of relays under the bonnet looking front/right to rear/left! The relay's causing you the problem are the ones marked in pic P/S/R and M/C/R



Andy

[taz turbo]

hallsie said:

where the bloody hell is the fuel pump relay on an early 280 FHC with all black wiring? I cant seem to see anything under the bonnet!

Pump is on the chassis located in front of the nearside rear wheel below the fuel tank.

Chris.

[benebob]

An easy way to check the pump is to run 12v to it directly. A jumper box works just fine for this.

[hallsie]

Mr Tank said:

hallsie

See atttached pic of relays under the bonnet looking front/right to rear/left! The relay's causing you the problem are the ones marked in pic P/S/R and M/C/R



Andy

Thanks Andy

The problem is....

The top line where you show 4 relays, I have one relay, which is the hazzard one on the right hand side looking at your pic, not the left.
The next line of relays below consists of 4 relays, all unknown.
the next line down there are 3 relays, again unknown but one has a feed going to two loose relays that control the headlamps pods...

Ive got to get the beast up in the air and remove the pump for testing, I did find a loose connection on the pump which I renewed but made no difference.
The feed cable to the pump is also suspect and the earth cable feed to the pump has been run directly from the battery, so it may well be just as easy to run another feed directly from the ignition, via a relay to the battery.

Stu

[Wedg1e]

hallsie said:

Thanks Andy

The problem is....

The top line where you show 4 relays, I have one relay, which is the hazzard one on the right hand side looking at your pic, not the left.
The next line of relays below consists of 4 relays, all unknown.
the next line down there are 3 relays, again unknown but one has a feed going to two loose relays that control the headlamps pods...

Ive got to get the beast up in the air and remove the pump for testing, I did find a loose connection on the pump which I renewed but made no difference.
The feed cable to the pump is also suspect and the earth cable feed to the pump has been run directly from the battery, so it may well be just as easy to run another feed directly from the ignition, via a relay to the battery.

Stu

Sounds about right; Tasmins had three relays just for the light pods. One each for starter, horn, heated rear screen (on the FHC) and two for the fuel injection system.
You should be able to deduce starter and horn easily enough; pull the relays out one at a time and see when they stop working Whatever's left ought to be the injection relays.

[hallsie]

Thanks Ian,

Ill have a play tonight, but by deduction, I have one less realy that needed.... but its a start!

Stu

[hallsie]

Well

It appears that Im a berk!!

After remoing the wheel for better access and putting a feed to the pump (which works) I followed the wiring back and found that I had managed to disconnect the main feed from the ignition whilst buggering around with the switchplate!

But on the plus side, Ive now worked out that the pump does not go through a relay, and Ive also made a start on tracing the relays in the front!!

So at all ends well, thanks for the help!!

Stu

[niva441]

After much head scratching I discovered my early build +2 also didn't have a fuel pump relay. As I recall I should have been switched using a switch on inside the air flow measuring flap.