J30 Fuel Problem

[Bugaboo]

The fuel tank will hold 19 gallons per owners manual. I let the gauge go to empty. After I put in a full tank the pump says I only put in 10 to 12 gallons. Do this mean the gauge is wrong or is the tank really that small?

Has anyone else had or heard of this problem?

[driverdriver]

This is somewhat speculative answer to your problem. I've had a similiar problem happen to 2 non Infiniti vehicle. I believe your fuel pump/sending unit is done. You let it go to far into empty as a result it sucked in the gas gauge float a recaliberated your fuel tank readings. Do you hear a slight humming or buzzing from your fuel tank door/area?

[Bugaboo]

I have heard no noise coming from the tank or trunk area.

Does any company (Lucas, STP) offer something to clean the unit with out having to remove the tank?

[driverdriver]

You can try a fuel system treatment, but be warned they are more for cleaning the injectors that the tank.

Have you run a fuel pump pressure check for both the fuel pumps (there is more than one on the J) and the fuel sending unit?

If not I would suggest it.

Access to the fuel tank is achieved by removing the back seats.

[DominickJ30]

Two fuel pumps??? Please explain.

Also an easier way of gettin to the tank would be to remove the rear wll in the trunk, its only a couple of screws and its much easier to work from the trunk side.

[driverdriver]

Two fuel pumps??? Please explain.

There is only one. I was thinking of another car that I'm close to acquiring.

[DominickJ30]

What kind of car?

[driverdriver]

'02 XJR I've always coveted Jags.