I have an 86 XJ6 with the classic problem of fuel rolling from tank to tank. I am constantly switching tanks as the car sputters from losing fuel in the tank it’s on.

I have switched all three components (the main valve in the trunk and both in the wheel wells) and it continues to do the same thing. I can’t figure it out.

Where else do I look?

I am brand new to Jags and I love this car, but this is seriously driving me crazy.

 

When you operate the switch on the dash do you hear all three of the valves operate? You should. You might need a helper to work the switch while you check

If not, post back

Cheers
DD

 

I believe so. I also hear something operating when the fuel gets low and I need to switch tanks. When the fuel gauge hits the high mark for the fuel level, it sputters and I have to switch it to the other tank, which shows no gas, but runs until it fills up.

I also read on another thread that people have just put in straight lines and bypassed the valves altogether. Is this a bad idea? If it works, I have no problem doing it. I’m driving the car, not taking it to shows.

 

Perhaps the new valves on the return lines are not fitted to the correct sides? They are handed, one being normally open and the other normally closed.

 

They will only fit their respective sides.

 

One more thought….could the two-way valve from the tanks to the pump be connected incorrectly, so it’s drawing from the wrong side?

 

I hadn’t thought of that. When I hooked up the new one, I simply did it exactly like the old one, assuming it was correct, but perhaps the old one was wrong. I’ll do some research and see. That might explain a few things.

 

So,I took out the valve in the trunk and replaced it with a simple brass T, and left the two side valves inline and powered. It now seems to be functioning as it should. I have 1/2 tank in each side (slightly less on one side) and the gauges show it. As well, gas is no longer moving from tank to tank and it will drive on either tank. What am I missing? I assume that if I take out. component, it shouldn’t suddenly operate correctly. If it works, don’t change it, is generally my motto, but it still makes me nervous.

 

You're not missing anything. The two tanks are now connected and the level in each should always be the same. It doesn't matter, now, which tank fuel is returned to. Many have done exactly what you've done.

The only possible problem.....oft mentioned but seemingly never materializing....is that one tank could overflow if the car is parked on a slant. That is, one side lower than the other.

Cheers
DD

 

Thanks! I appreciate the guidance, and the reassurance!

 

would it be possible for you to take and post a picture of this modification as i will most likely do the same as you? thank you in advance, ren