I have a 91 XJ and i just installed a new Delphi fuel pump, now I am getting a humming/vibration noise from the pump. The odd thing is that if I disconnect the vacuum line to the Fuel Pressure Regulator (FPR) the noise stops. I am not sure if the issue is the fuel pump or the possibly the fuel filter. I also recently replaced the FPR but I put the old one back on and the fuel pump makes the same noise when the vacuum line is connected to either pump. The noise is constant while the Jeep is on. I am getting about 35PSI with the vacuum line connected and about 42 with it disconnected.
I have seen many people with similar issues but I do not want to buy another fuel pump and instal if it is going to do the same thing.
91 XJ
4.0
Automatic
I have seen many people with similar issues but I do not want to buy another fuel pump and instal if it is going to do the same thing.
91 XJ
4.0
Automatic