Hello members!

I’m hoping you could share your knowledge on trouble shooting my 1986 XJ6 - it was just dropped off, and I was all smiles enjoy the Jaguar ownership until I found that . . . . it would not start.

I’ll have to deal with the shady seller separately (giving me the old “it’s been running with no issues”), but the symptoms is that I can jump start it once in a while, and engine fires up, but it’s very difficult to keep it running for more than 5-10 seconds.

I first thought it may be an alternator issue, but in researching this forum, I find that there could be many other possibilities like issues with AFM valve/flap, ECU not getting 12V, may be an electrical issue around fuel injectors…..

Any suggestions on where to look would be greatly appreciated, and if anyone happens to be in the NYC area, any recommendations on Jaguar mechanic would be much appreciated as well in case I need to a deep dive beyond my capacity …. (Jagpro seem to get a few mentions here?).

Best,

 

If it starts and runs for about 5-10 seconds, then it points to the fuel supply, (that's my view anyway).
This article tells you all about the EFI system by an engineer who was there at the time.
Fuel injection and the Jaguar XJ6 4.2 Series 3 / AJ6 Engineering
As an analogue system one cannot just plug in a diagnostics package and look for faults, one has to go back to basics.

 

If you want to read more about many things to check, this main page has links to tons of info. The FAQ link has detailed info by category and I would read the Engine and Fuel sections

https://www.jag-lovers.org/xjlovers/faqsandinfo.html

Good luck. Mine did not run when I got it and finally I fixed a few things and there was joy!

Randy

 

Thank you ! wonderful link, will go one by one.

 

Thank. you Randy, looking forward to driving it. Will report back on any progress.

 

I had my 1987 XJ6 SIII towed home. Previous owner couldn't get it to start. Using my trusty Multi-metter I started to diagnose by going through each component of the ignition system, testing each for voltage and ohms resistance. Spark plugs, Spark plug wires, distributor cap, vacuum advance, CEI amp, coil and condensor, I found the CES amp was out of spec. Ordered a new one, and still no start. I then tested the pick-up in the distributor, and wholla, no spec. Ordered a new one and it fired right up. Due diligence on these cars will reward you with the satisfaction of driving a classic.