Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Fuel pump relay / +8 from 1980

I have inherited a Plus 8, built in 1980 from my father.
The car wasn’t driven in the past five years.
Currently I am going to prepare the car.

Unfortunately I have not yet managed to provide the fuel pump with electricity.
If I give directly 12V electricity to the pump, it runs.
I suspect that the pump is switched via a relay. Is that right?

Where is this relay for the fuel pump?

For any help I would be grateful!

I personally don't use a relay. It is typically switched by the key or by a Power Cut Off switch. I just wire to 12v. The newer electric fuel pumps draw very little amperage. (I have used Facet pumps on three different 80s vintage Plus 8s) They only draw somewhere around 2 Amps.

I reserve relay use fro much higher amperage (eg, 30/60 amps). I would be sure to fuse the circuit, though.

Cheers,

I think that the original fitment included a fuel pump relay which is one of three mounted on the bulkhead behind the dashboard. The fuel pump relay is one of the outer ones (which are both the same) so you could swop them to see if you then get fuel (although the other may be the starter relay so the engine may not turn over!)

Couldn't find one on the wiring diagram?? I could be wrong. Malcolm, do you have one on yours??

FYI, fuel injection is high pressure, so EFI would require a stronger pump (and draw higher amps.) Carburetors (aka 1980s) were relatively low pressure (7 psi or so). But be sure to verify, I am just speaking from memory.

Cheers,

Might be wrong, just looked at the date of the car in question. Mine is a 1987 with Flapper injection. Sorry....

I do not believe that a post 1977 Plus Eight was fitted with a fuel pump relay.

It sounds as if you have access to a wiring diagram so that should be your source of reference.

The supply to the pump will be from one of the circuits that is open when the ignition key is turned on.

An alternative reference may be a Haynes manual for a Rover SD1. My 1976 Plus Eight's wiring diagram closely follows a Rover 3500 P6 even down to the cable colours. You may find that the same principle of using an SD1's wiring features was followed on your 1980 car.

there may also be a pressure switch at the oil filter housing which cuts off the fuel pump if there is no oil pressure as a safety feature. It is a 3 spade terminal screw in fitting if fitted. I don't know over which years it was present.
cheers