2003 Dodge Quad Cab, 6 speed tranny,4x4

My truck turn over 91K miles not long ago and I noticed the injector pump leaking fuel. The dealer replaced it and I asked the mechanic if the lift pump could have caused it to go bad. He said yes, and my lift pump check out okay. I asked him how he checked it out and he said by pressure and by how much fuel went into a bucket in one minute. I thought this was a stupid way of doing it. Anyway two weeks later my Lift pump went up. They put the new one in the fuel tank instead of the engine. They said it was a new upgrade. I was getting 23 miles to the gallon of fuel. Now since this all has happened I'am getting 18.5 miles to the gallon. Is there something still wrong or just new equipment that needs to be broke in? The dealer replaced my injector pump with a rebuilt one. I thought vehicles under warranty received new parts.

 

The method he used is the way its done , to test a pump there are 2 factors , pressure & volume .
It seems that these trucks are detuned for P/U use , and when we put a little more fuel to them they get better MPGs , so you may want to put an after market fuel system in it to make it better.

 

There should not be any "break-in period" for the CP3 injection pump or the lift pump.

Have you replaced your fuel filter recently?

The new hardware shouldn't cause a decrease in mileage. You might want to have the rebuilt injection pump pressure tested. A poor performing injection pump may cause mileage issues.

You might want to request a new pump (not remanufactured) if your rebuilt unit does not meet the pressure specification.

Good luck.