Priming fuel pump relay

[Else]

Can anyone help me to find a fuel pump relay that primes for a couple of seconds when ignition turned on and has the tacho connection to keep it on while the engine is running.

I have a Lucas FDB503 that doesn't prime when Ign turned on.

Existing connections are:
Permanent live 30
Earth 31
Coil (tacho) negative 1
Switched live (ign on) 15
Output to fuel pump 87

Thanks Andy

[nawarne]

This from www.chimaerapages.com lots of useful info here:

Fuel pump relays Euro car parts 450110050
BMW Part 12631729 OR

Fuel pump & injection relays Bosch 0732014112 or Land Rover part AFU2913L.
This is the one I think you refer to - usually Bosch part aluminium cover/case has red diagonal stripe on it. However, last one I saw from Racing Green had a brown plastic casing.

Nick

[Else]

Thanks but that's a regular relay, my car has a fuel pump relay that detects the signal from the low tension side of the coil before energising the relay you referred to. If the engine stops then the relay cuts the power to the pump.

Andy

[Mr Jenks]

Normally they use a standard relay, switched by the ECU. The only thing I can think that you are thinking of is the old style "Tachymetric relay", used on some earlier K-jetronic equipped vehicles, some carburettor/turbo setups had similar
may help
or this

[Else]

Thanks very much guys, hoping one of our knowledgeable members may be able to point me in the right direction.

Andy

[NZDave]

I have been investigating these relays as mine failed. Not easy to find here in New Zealand. I think you need a Lucas FDB502. This should have the prime function.
Dave

[S6PNJ]

From the Tuscan parts wiki, there is an entry for the fuel pump relay. When the ingnition is 'armed' one side energises for about 2-3 seconds then stops. Once the engine is running, the other half energises and carries on 'pumping'
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
I had issues with my fuel pump/relay and found the part number which is in the wiki.

[Else]

Thanks guys, I went for a Lucas FDB502 in the end, it gives about 1 second of prime which just about does it.

Andy