Jaguar Repair: 1986 jaguar xj6 wont start but cranks

Question
Hello, I have a 1986 jaguar xj6, not really sure of the series. I put a new battery in it and when I turn the key it will crank and crank but won't start, I've tried pumping it and get nothing. I did do a lot of reading up on it and found that it had two gas tanks, one of the gas tanks was compleatly dry and empty when I got the car, I put some gas in it and found that it has three holes in the bottom but the driver side gas tank is in good shape and I put a gallon or so in it, I wasn't very sure how much was in it when I got it but I could small gas. So during my research on the car I figured out there is a button on the dash which switches the tanks, well I pressed the button and nothing happened, I did notice that the button didn't come out when pressed like the others on the dash were out and went in when pressed. And I also read that there are arrows on the button which show what gas tank is in use, but neither of the arrows on the button turned on when the far turned on or wile it was trying to start. I also did read that the gas tanks are pressurized and I noticed when I turned on the radio once I herd some type of pumping noise back near the driver side back wheel or quarter panel. I don't know much about the car and I do not have an owners manual if you could give me some ideas or anything that I could do to just get it running would be great. Thanks for your time.

Answer
Hi Corey,

The 86 XJ-6 is a series III car. The fuel button on the dash is the switching control for right tank and left tank. (Also the fuel gauge for each tank)

You may have nore then one problem so you need to do some tests. They are not difficult but you do need a few tools. Since there was an existing fuel problem you need to find out if the fuel delivery system is operating. The marking on the fuel switch is on the right side of the button. "R" & "L". The left tank is the "Default" tank meaning if there is any electrical failure in the switching valve system the left tank will still operate. It is simple to test.

Remove the clamping screws on the short hose between the air cleaner and the air flow meter and slid the aircleaner forward. Turn the ignition key to "ON" (not "Start") and reach into the front of the airflow meter and feel the Flap door and open it by hand. As soon as you do, you should hear fuel rushing through the fuel rail at the injectors.

If you do hear it, go open both gas caps and take a screwdriver or such and put in in the front of the air flow meter to hold the flap door open. Then go back to the open gas caps and use a flash light to look down inside and hold the small fap door open and look for fuel returning to that tank. If you don't see any fuel look at the other tank cap. If you don't see any fuel returning in either tank filler neck press the fuel tank switching switch one time and check both again.

If you don't get any sound from the fuel rail when opening the airflow meter flap while in either switch position you will need to get a 12v test light and let me know and I will then walk you through the tests of the fuel system.

You will also need a compression test gauge and normal hand tools. Let me know and I will walk you through all the tests necessary to get it running or know exactly why it don't run.

Howard