The M3W fuel pump module is a Land Rover Discovery V8 EFi, late 1990's item p/n WFX101020. It requires the fuel contents part modifying to fit, as its doesn't use it. If you get one of these it will be a direct replacement and as unreliable as the original. If you want to replace just the pump, as that is all that has failed the module, the original is a Delphi FE0113 (maybe), this will be cheaper but not better.
I have just fitted a Walbro GSS342, that the Disco guys on their forum think is a much better pump. Other than running it in my garage idle and a short blast up and down the road, I cannot say if it all works as it should yet but it seems good and is supposed to be a much better pump with not too high a current draw, as many high flow pumps are. I will let you know if it is all it is supposed to be in a few months time after I have some miles on it.
The sure sign of pump failure is to check the pressure at the test point on the injector, it should be 58psi. Changing the pump in the module takes a bit of time but isn't too tricky. The detailed parts required are on my alternative parts list.
