Fuel pump/immobiliser problems....

[G5FTH]

Hi All,
I went out for a drive on Saturday and all is well with the car until I stopped for fuel.
After filling I turned on the ignition and pressed the fob but the fuel pump didn't whirr. I tried it several times, over and over - locking and unlocking etc until 5 mins later it all worked as normal.

I then set off with the car running great until it cut out. The engine just stopped. It wouldnt fire but would turn over.
Then I heard a relay click, it started and ran again.
In short I have a relay clicking off/on randomly stopping the engine. I shorted it out with a cable to rule it out, the car still runs sometimes and then cuts out.

This leads me to what feeds the relay? I cannot see the fuel pump on the simple wiring diagram I have.
I think the relay is either fuel pump or immobiliser.

Does anyone have a wiring diagram of the immobiliser and fuel pump?

Any help is appreciated.

[Hedgehopper]

Can't help with a wiring diagram but this is where the fuel pump relay is hidden.

Note, it is a special electronic relay...usually Bosch with a stripe across it.

Hope this helps.

[WinstonWolf]

Replace the pump and ECU relay as a pair.

[G5FTH]

The pump was replaced a few months ago with a Bosch unit (IIRC).
The problem is that the relay is clicking off/on and the problem doesnt go away when I short out the relay.
This makes me think that the signal to the relay is dropping out. I just dont know what feeds the relay.

[Hedgehopper]

This any help?..........

http://www.bertram-hill.com/fuel-pump-schematic.ht...

[G5FTH]

Hedgehopper said:

This any help?..........

http://www.bertram-hill.com/fuel-pump-schematic.ht...

Really helpful - Thanks!

Going off this wiring diagram the coil of the fuel pump relay is fed direct from the ecu. I think the other relay (shown in the picture above as "ecu relay") was clicking at the same time.
This would indicate that its the ecu relay dropping out causing the fuel pump relay to drop out.
Does anyone know what feeds the ecu relay?

edited to say after reading the description on the link above for the wiring diagram its possibly one of the plug/socket connections described but this would not explain why the relay was clicking on/off.

Thanks.

Edited by G5FTH on Sunday 25th September 19:12

Edited by G5FTH on Sunday 25th September 19:56

[EGB]

Had similar problems. Fixed by byepassing immobiliser.