Hi All,

Please my 1985 XJ6 is ready to hit the road but recently the car refuses to start from the ignition key. What could be the possible cause and how do i fix that problem?

Please help.

Mike

Are you saying that the car will start by jumping the starter solenoid and not from the ignition key? Does the fuel pump run, do you get ignition lights? Does the starter turn the motor over. Need more details please.

Hi Ian,

1. Yes, the car will start by jumping the starter solenoid and not from the ignition.
2. Yes Fuel Pump run
3. Yes Ignition lights comes

Thanks for your support.

Mike

Look at top of forum page under "Stickies" There you can download the S57 wiring diagrams. See Fig. 2.1 for troubleshooting.

I'd durn near but not quite bet on the neutral start interrupt circuit. The device allows the completion of the ground leg of the relay trigger circuit only when the shift lever is in N or P.


Wiggling the shift lever at P when turning the key may enable the completion of that circuit and the engine will crank and fire.


So, either jump from rely to ground and be very careful to make sure you do not fire up with the shift in a drive position. D o R.


Or, do it right and track the continuity back to the switch. On the BW, I recall it being on the left side of the transmission, a part of the reverse lamp circuit.


A clue "might" be if the white lamps at the rear of the car do not light up with the engine running and the trans in R.


Ditto on the S57. Checking wires with out it is flying blind.


Carl

Use the diagram and check for power from the ignition on the relays at the firewall. From there you should be able to tell if the issue is within the ignition circuit (no power to relay), the relay itself, or between the starter and the relay.

Engine Will Not Crank Checklist


Cheers
DD

is it that the ignition switch doesn't do anything when you turn it to START??

or does the engine crank but no start?

Two different scenarios. If the Ignition switch doesn't do anything, it might be the switch.

Jose,

Engine cranks but no start.

Hello, Mike,
It looks like several months have gone by with no progress on this problem of yours.
Perhaps my experience with this exact scenario on another vehicle will help you.

One morning in 2009 my work truck wouldn't start again after I had it running for a while. Cranked just fine, good battery etc.
After fighting with it for a Looooong time, it fired up and I worked the rest of the day without ever shutting it off for fear it wouldn't start again if I did.

After exhaustive trouble shooting husbnd discovered the ignition switch was the culprit. The START contact worked as it should and engine would run while turned to START, but the the RUN contact within the switch itself failed to keep the engine running as it was worn away almost to nothing. If I held my mouth Just Right it would continue running but stopped at the first bump in the road. I had been fortunate not to hit any bumps that day.

He changed out the electrical contact part of the switch so my key still works and it's not missed a beat since.
Perhaps this is similar to your problem.
(';')

also check the silly things:

1) do you have enough fuel in both tanks?

2) try changing tanks while trying to start, push the fuel tanks button.

3) place the shifter in position 1, crank the switch to start, (it will not start in shifter position 1), BUT can you hear the fuel pump making a "hummm" or "whinning" noise?? If yes, that is a good sign, it means the pump is pushing fuel.

Well, a time back I was in amess. Crank issues, and more. All fixed with a NOS ignition switch from David Boger at Everydayxj.


A lot of odd misbeaviour vanished!!

Switch just plumb wore out.
The new one is so much tighter as I turn it. The LT1 fires up almost instantly...
Carl

Hi All,
Now the issue left on the Jag is after starting, the fire would not stay for long and it goes off few minutes.
Could that be the ignition switch?
what could be the cause of the fire not staying?

Thanks, Michael.

Hi All,
Now the issue left on the Jag is after starting, the fire would not stay for long and it goes off few minutes.
Could that be the ignition switch?
​​​​​​​what could be the cause of the fire not staying?

Thanks, Michael.

Hmmm Jose,
I have more fuel in both tank which I realized that tanks are full and even fuel overflow the tanks.

Fuel pump works well but fire does not stay longer when finally started from ignition key.

then it may be the ignition switch.

if you can start the engine now, right aqfter you start it, gently touch the key at the ignition switch to see if the engine shuts down. If it does, the ignition swwitch is worn out. It can be opened and repaired if you are handy.