lrjohn · Sunday at 17:01

I have the fuel tank out on my 1990 Discovery 1 3.5 carburettor model to get at chassis for welding. The fuel pump on the top at least looks pretty bad and the connections were difficult to release. I’m thinking to change the pump while it’s out there is a confusing picture on possible replacements. Best as I can find out the correct pump is part number PRC7129 which is rather expensive, around £150 to £175. Some of the aftermarket suppliers Britpart pumps for Discovery 1 which are a lot cheaper, around £70, and they looked exactly the same except for the electrical connection, the one I have is a cable coming out of it whereas other ones have a socket for a cable to plug in. Pump and send the unit are simple wiring so I’m sure a conversion is possible.

The body had the experience of replacing one of these pumps with non-standard near so what did you use please?

Pictures of existing pump below the minor

sierrafery · Sunday at 18:19

lrjohn said:
they looked exactly the same except for the electrical connection, the one I have is a cable coming out of it whereas other ones have a socket for a cable to plug in

As long as the socket on the pump has the same shape and pinout like the female plug on the old pump's cable and it accepts the vehicle's male plug which can reach the socket it should be plug and play even though rewiring such pump is not something hard to do

lrjohn · Sunday at 18:28

sierrafery said:
As long as the socket on the pump has the same shape and pinout like the female plug on the old pump's cable and it accepts the vehicle's male plug which can reach the socket it should be plug and play even though rewiring such pump is not something hard to do

Thankyou for your response. Do you know if the pump used on a fuel injection Discovery 1 and carb version are the same in terms of fuel delivery and return pipe?

sierrafery · Sunday at 18:42

lrjohn said:
Do you know if the pump used on a fuel injection Discovery 1 and carb version are the same in terms of fuel delivery and return pipe?

Sorry, i have no ideea

discool · Sunday at 19:10

lrjohn said:
Thankyou for your response. Do you know if the pump used on a fuel injection Discovery 1 and carb version are the same in terms of fuel delivery and return pipe?

Different part numbers for a start, plus the EFI’s have around four variations over the years, so in my experience I would say no.
My quick search gives the part number you gave as a 200Tdi pump, you need PRC9409 pump for the twin carb V8, which appears to have the correct power connector. Pic below.

I would expect the genuine pump would be obsolete by now, but it appears that the OEM pumps are manufactured still,which Britpart can supply, possibly along with a genuine pump if the had one.

Just to add , I looked in my parts book now i’m home and it gives a number as PRC7128, PRC4909 is for 93 disco EFI and that is expensive.

hef19898 · Sunday at 21:15

The fuel injection pumps have way to much pressure. An alternative would be a Red Top Focet pump. Those are inline so, I have one in the engine bay on a 3.5 carb RRC. Works great. Not sure if that setup works on a Disco 1, it should so, as the underside is basically the same thing. Not sure about the tank.

lrjohn · 2025-08-25T19:18:37+0100

discool said:
Different part numbers for a start, plus the EFI’s have around four variations over the years, so in my experience I would say no.
My quick search gives the part number you gave as a 200Tdi pump, you need PRC9409 pump for the twin carb V8, which appears to have the correct power connector. Pic below.

I would expect the genuine pump would be obsolete by now, but it appears that the OEM pumps are manufactured still,which Britpart can supply, possibly along with a genuine pump if the had one.

Just to add , I looked in my parts book now i’m home and it gives a number as PRC7128, PRC4909 is for 93 disco EFI and that is expensive.

Thank you! I just googled the part number you gave, 7128, and on the official Jaguar Land Rover site it does come up as the correct one for the V8 – thanks again!

lrjohn · 2025-08-26T17:45:40+0100

hef19898 said:
The fuel injection pumps have way to much pressure. An alternative would be a Red Top Focet pump. Those are inline so, I have one in the engine bay on a 3.5 carb RRC. Works great. Not sure if that setup works on a Disco 1, it should so, as the underside is basically the same thing. Not sure about the tank.

Thank you very much for responding, as far as I can find out today the correct pump for carburettor D1 V8, PRC 7128, is no longer available. So I am thinking your solution of an in-line pump may be the only route but I'm interested in how it works? Do you leave the original pump and fuel gauge sender so you still have the fuel gauge operating? Then do you plumb the in-line pump direct to the fuel line to pull fuel through the old pump? Would very much appreciate your comments, thanks

sierrafery · 2025-08-26T19:08:21+0100

discool said:
you need PRC9409 pump for the twin carb V8,

lrjohn said:
the correct pump for carburettor D1 V8, PRC 7128

So what's the trouble with the PRC9409 which is similar with the one from you first pic cos i dont understand :vb-headbang:

hef19898 · 2025-08-26T19:35:09+0100

lrjohn said:
Thank you very much for responding, as far as I can find out today the correct pump for carburettor D1 V8, PRC 7128, is no longer available. So I am thinking your solution of an in-line pump may be the only route but I'm interested in how it works? Do you leave the original pump and fuel gauge sender so you still have the fuel gauge operating? Then do you plumb the in-line pump direct to the fuel line to pull fuel through the old pump? Would very much appreciate your comments, thanks

It was already installed when I bought the car. Since then, she got a new fuel tank, a disco 1 if memory serves well as that was done at a garage. And a new sender unit, I think it was the pre-85 sender unit. The fuel line goes straight to a plug in the tank, then to the pump, then to the filter and from to the left hand carb.

If you have a tank with an old RRC sender unit without fuel pump, the installation is as above.

lrjohn · 2025-08-26T20:08:43+0100

I was told by

sierrafery said:
So what's the trouble with the PRC9409 which is similar with the one from you first pic cos i dont understand

RImmer Bros today that that on is for Efi version and therfore has too much pressure. I dint quite follow that as tge carb version has a return pipe so should simply return surplus fuel. But perhaps the extra pressure overcomes the float valve and floods tge carbs??

hef19898 · 2025-08-26T20:29:13+0100

In the double carb set up, at least my double Zeniths, there is fuel return line from the right hand carb. The pump fills the float chamber of the left one, then the right one. Any excess fuel goes back to the tank. To much pressure might flood the carbs.

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