hi all i've just changed my noisey fuel pump on my z when i went to remove the old pump i found that the blue wire coming from the sender/pump loom (fuel pump neg connection) has been spliced and connected to earth so the fuel pump is constantly trying to prime the fuel system,fitted the new pump and without the extra earth connection fuel pump does not work,i've checked fuel pump relay and thats ok cant find where the blue wire from the fuel pump neg is supposed to run to could it be i have a prob with my fuel pump controller? many thanks for any help in advance kev

bump

White-zed

 

What you have found is a common work around or get you home trick for a failed fuel pump controller.

 

Nissan oddly utalise earth switching in several places on the zed and the contoller is one of these.The cable you have found earthed out would normally be connected to the output from the controller, this would ramp the voltage up and down according to conditions and loads.

 

As your pump cable is earthed out it will run at full voltage and all the time, this will eventually lead to an early demise of the pump and be the cause of excessive pump noise.

 

You need to check out the contoller which is located at by the rear seat on the passenger side behind the rear quarter panel cover.

 

The controller is a silver box with cooling fins on, dismantle it and inspect the pcb for overheated components that have become dry joints, use a soledring iron to reconnect any bad connections and try the unit again in the car.

 

Hopefully all will work again, if not a new controller will be required, as these are silly money brand new a good working used one or at least one with some warranty can be aquired. In the past 10 months or so I have seen an increase in the pump contoller faults double, treble even maybe a sign of the times age wise.

 

Hope that helps.

 

Jeff TT

many thanks jeff looks like thats gonna be my next job luckily i've got to have the rear panels out next weekend so a good time to sort both probs