Classic/Antique Car Repair: fuel & electrical, air flow meter, fuse box

Question
my 84 xj6 4 door 4.2 fuel empied from 1 tank into the other. when i restarted,it was a lot harder then usual & didnt want 2 stay running became harder  & harder until it will not start. problem 2 no h. loghts fuse under dash ok what do i do.THANKS MUCH

Answer
Hi Leland,
The transfer of fuel from one tank to the other is most likely a failure of a return valve. The system is designed so that in the case of any failure in the system it will run off of the left tank. However, if the system has a failure and you try to run off of the right tank the return fuel (most of the fuel that is pumped to the engine is not used and returned to the fuel tank) it will be returned to the left tank while you are running on the right tank. Thus over filling the left tank.

To confirm what has failed, start the car and open both fuel caps and with a flashlight look down into the filler neck to see which tank is receiving return fuel. (the return line is close to the filler neck)Check them while running on the right tank, then check them while running on the left tank. You should see and hear fuel running into the left tank when that tank is being used and the same for the right tank.

If the car will not run remove the air filter and turn the ignition switch to just the "ON" position (instrument warning lights ON). Then with a screwdriver or a finger push open the spring loaded door inside of the air flow meter (unit just behind the air filter) You should hear the fuel pump start running in the trunk. You can then look and listen in the filler necks to see that the fuel is returning to the correct tank. E-mail me the results of this test and I will have you do the next step. http://www.mg-tri-jag.net

As for the head lights, look at the head light fuses in the small fuse box under the hood on top of the left fender well.

Has this car been setting for a while? This is common when this car is not in continuous use.

Howard