So I bought this 1987 XJ6 about a month and a half ago. The previous owner told me they hadn't used the passenger side tank because a fence fell on the car and made a dent in the body last winter. No, the dent didn't make it to the tank.

I want to use both tanks, but....alas...I'm scared to switch tanks. Not because of the old(?) gas in the tank, but because of the Lucas switch. I'm scared that if I hit the switch that it will flip tanks, but not switch back again. Why? Because how will I know which tank it's on if the switch fails? I can't really tap out morse code on that switch to flip tanks like I have to on the windows because I don't know if the float works on the passenger tank.

Hep meh, hep meh, hep meh!!!

 

Fair Dinkum, you had me for a minute HAHA.

I would be more worried about what is actually in that tank, and the damage it is going to do if you DONT flush it before switching over.

In all my Series Jags with that switch, NONE have failed, FACT. In fact very little Lucas stuff actually FAILED. Bad earths, nothing to do with the switch, failed, but Lucas did not do that bit, Jaguar (Leyland) did that.

Drain that tank, flush it, refill with a specific amount, and switch over.

If the "brown stuff" hits the fan, pull the switch and join the wires, and drive the car.

 

I'm afraid yer gonjust gonna have to take the plunge

But, as Grant says, drain the unused tank. Who knows what might be in there.

If for some reason draining the tank isn't in the cards then post back for alternatives.

If there's a problem with the changeover system it can be fixed...or you can forget about it and continue running on one tank.

Cheers
DD

 

not to jump in but i cant stress enough what these fellows have said.

i was working for a jaguar dealer friend the other day and we went to fire up a car that had sat for years. drained the tank and thanks to a blocked drain in the cap there was literally at least 10 litres of water in there before any petrol cam out. this car is extreme but they all seem to have some amount of water in there.

once you drain it with the small bolt remove the plug from the bottom of the tank and flush some fresh petrol through and clean the screen. the longer its in there the worse it will be, especially if you drive around with water sloshing everywhere in there. after that a new filter and some petrol and apart from maybe sticking change over valves you wont have an issue and can be confident using both tanks.

regards jay

 

I had a crib note in my cubby for years. Left in, right out!! Finaly decided to brave going on grey matter alone. Just did!!

I recall a tale of a CFO for a large corporation. After his retirement, some one found notes in his desk drawers. One on the left said debit followed by a minus sign. Another on the right said plus followed by a + sign.

Care when tank draining, the large nut is just as likely to come out as the smaller one. have a big pan, lots may come out.

 

I first switched mine over in the comfort and security of my own driveway. Not surprisingly, like everything else on my old girl, the tank switchover works perfectly.

I would imagine it's quite limiting running with 1 tank only..... I don't think I'd get 100 miles out of 1 tank....

 

really? I could get 150 if I pushed it, not that that's a good idea at all though haha. I usually go half way down on the left tank, fill it switch to the right get halfway down and repeat. but on tight weeks I've put 300 miles down before gassing both tanks up.

 

Mine is my commuter car. I get 18+ miles to the gallon, so i can go 176 miles on 9.5 gallons from the left tank, which is just above the empty mark. Of course, it's been lumped with a chevy 350 and a GM transmission.

 

I just took the plunge and filled up the other tank. No problems so far. Still using the right as primary though.