Jaguar Repair: finder well switch valve/s 85 xj6 jaguar, xj6 jaguar, haynes manual

Question
QUESTION: what is the most common couse of cold start valve dont get fire in wires and no spray..and can i take a switch valve from one side of car and mount on other side. the one in rear wheel opning. and whitch way do the fuel travel on left fuel line toward engin or toward fual tank.thats on 85 jaguar xj67

ANSWER: Sound like your cold start relay is bad. It is mounted on the fire wall. The fuel travel from each tank to the fuel pump in the trunk. It leaves the pump and goes to the fuel filter and to the fuel return valve and then to the engine. The other fuel lines are return lines to the tank. Please go to welshent.com and see if the parts numbers are the same. Good luck. Sammie

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QUESTION: i have gas pumping from left tank to rt// tank whitch switch valvi is bad. whin i switch to left tank it pumps fuel to rt/ tank. i replace a switch from rt// side of a nother car to lf// side will that work and  whitch way should the spring loaded end b//towatd tank or toward engin//pleas help thanks///

ANSWER: You can not use the right side valve on the left side. It sounds like your tank change over valve is bad. Fuel will leak from the left side tank to the right side tank if the valve is stuck between the two tanks. Tap on the change over valve and that might un stick the valve.
The round side of the return valve will face the front of your car. It should only fit one way.
Please buy a Haynes manual it will show you how to mount the valve. Sammie

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QUESTION: i got a fuel solenoid from a junk yard for my 85 xj6 jaguar from rt// side of car. put on my car Lf// side when i switch tanks both valvs work the same way what i/am saying both valvs open and close at the same time when rt// valve is open LF// valve open also and when LF valve close RT//valve is close. and fuel return to both tanks in any posision is those switches wired differn to change the pourlty.or do i have another problem.

Answer
That is the way those valves work. They are both closed when the car is off and are open when the car is on. They stop the fuel from returning to the tanks when the car is off, maintaining fuel pressure when the car is started. I have added some links that may help you.  Sammie

http://www.welshent.com/catalogs/welsh_xj6.pdf
http://www.themotorbookstore.com/xj6.html
Jaguar XJ6 Repair & Service Manual 1968-1986