I am the proud owner of a 1986 XJ6 which I love. However I have run into some problems, and would like some input before I spend money taking it into the shop. 1st off, the XJ6 has dual tanks. However, only one take works. If I fill up both tanks, no matter what take I'm using, it will only take gas out of the right tank. Because of this, I often run out of gas and am stranded. Despite their being a full tank in the left side. It is very frustrating. 2nd off, the car only starts in neutral. Im not sure what the problem is there, but the car will not start in Park. only in Neutral. And to further the problem with the starting, it takes a while to start. I recently replaced the battery with a brand new one, yet it sounds like the batter is almost dead. Could this be a problem with the starter? Any help would be hugely appreciated before I take it into the shop. Thank you in advance!

 

The dual tank design is problematic. Do a search there is lots of info on checking the valves, checking the selector switch and general trouble shooting. There is also info on bridging the tanks as one which I'd recommend. Make sure your tank are clean and not rusting. Also consider a pre-pump filter. Search is your friend...there is a thread with the proper Wix part number to use as a pre-pump filter because todays ethanol fuel cause more corrosion than gas from days gone by.

As for starting in N...check the Park Nuetral switch on the shifter. Do you car go fully into park? You're shifter may need an adjustment or the switch is on the way out. Its easy to remove the console cover...there are two screws for the driver info / switch panel, and then you'll need to remove the climate control knobs and round nuts to remove the HVAC panel. Then the console panel comes up. While you are in there you can check the tank selector switch too.

Check your battery cables and ground strap connections. Check your alternator...Autozone will test it for free it may not be charging the battery properly. You can simply use a digital volt meter to measure the voltage at the battery, then measure the voltage at the back of the alt. You should see 13.5 to 14.3 volts with all the accessories off. The voltage should be the same. Any discrepancy indicates resistance in the connections or wires. A reading lower than 13.5v at the back of the alt indicates a failing alternator. A solid ground from the battery to the engine is critical too.

 

Here's info on checking the fuel changeover system:

Fuel Tank Switchover Checklist, Series III XJ6



Here's info on adjusting the neutral safety switch (the title says "backup lamp" but the procedure is essentially the same). Note that on your car the switch is mounted on the left side of the transmission. Earlier Ser III models have a console/shift mounted switch.

Adjusting Backup Lamp Switch, Series III XJ6

I should add that some of the switches are not slotted to allow adjustment....but this is easily corrected by elongating the bolt hole.

Cheers
DD

 

Oh man, I cannot thank both of you enough. You have saved me so much money! I was going to take it into the shop but you guys saved me. Thank you so so so much!!!