My car has sat up for about 5 years. Car was running fine before parking it. now my fuel pump is not priming. I have 12v all the way to the pump. That is 12V for 2 sec then off and 12v constant at cranking. My fuel filter is dry as a powder house so no gas is being pumped.

There are three plugs from the pump. 2 little ones and 1 big one. The big one has a white wire ( 12V) and a black wire ( GRD) and a blue wire that appears to be wrapped around the ground wire. One the small wire 2 have 12V and one is ground. On the other wire 1 is 12v and other is ground. However there is not 12v supplied when cranking. I think this one supplies power to the float.

I have also heard that the oil sending unit has something to do with the fuel pump working ... is this true?

I grounded the pump to the frame of car to bypass the FPCU. The ECU says everything is ok. Fuel pump relay replaced

Question:

What could be my problem? The wiring, the pump or the oil sending unit ?

Thanks !!

 

OH.... its a 1990 Z32 300zx NA 2 seater

 

Fuel pump might simply be gummed up from sitting, if your getting some power at least to the fuel pump.

I'm guessing you already checked your fuses? Check around the ECU to make sure mice didnt find their way in there and start chewing up wires as well.

 

Also if I remember correctly, the oil pressure sender doesn't have anything to do with the fuel pump system. It just ran the gauge.

 

Thanks ! yeah the rats chewed through my AC tube, ate my title copy and insurance card, owners manual and a few autozone bags! lol

 

Yikes! Heres hoping they didnt feast on some wires!

 

Most intank fuel pumps will rust up if the car sits for a few months, especially if the tank is nearly empty.