Hi! I was hoping you could help me. I'm am a junior aviation electrician for the US Navy. My 1997 Jaguar XJ6 (US) has two misfires, and I've determined that the problem is the ignition wires, which are clearly damaged with cracked insulation and exposed conductor, or possibly may also be the Engine Control Unit (ECU) aka engine computer or "brain box." The trouble is, I'm not very experienced in my field, and I have ZERO experience with working on cars, so I have no idea where the ECU is or where the wires go. The ignition wires are part of a larger wire bundle, which disappears into the frame of the car so I can't follow it without taking the car apart. So my question is: where is the ECU in my 1997 Jaguar XJ6 (US) and how do I get to it? Do I have to take out a bunch of other parts to be able to reach it? Or is it somewhere easily accessible that I'm just overlooking? Also, do the ignition wires share a common circuit at any point? In other words, if 4 out of the 6 ignition wires are working properly, does that mean the ECU must also be working properly?

If you can help me fix this problem without going to an expensive shop, it would really help me out a lot. I'm poor. Thanks for your help!

PS) No, the problem isn't the fuel injectors, spark plugs, or ignition coils. The injectors were just cleaned, the spark plugs are brand new, and I switched and the ignition coils to see if the problem would follow and it didn't. The problem did follow, however, when I switch the damaged #1 ignition wire with the properly functioning #3 ignition wire.

Welcome to the forum gracehi88,

I've moved your question from General Tech Help to X300 forum. Members here with the same model will be able to help.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some info about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

See this thread

https://www.jaguarforums.com/forum/x...cation-123187/

Welcome to the forum. Coil failure is a common problem, so make sure that is not the cause of the misfire. The wires will have to be patched up, you don't want to consider the cost of a wiring harness.

Thanks! That was really helpful!

People keep mentioning coils when I discuss this problem. Are you talking about the six individual ignition coils that sit directly on top of the spark plugs? Or is there some sort of master coil that powers all of them? Excuse my ignorance, but I'm asking because I've determined that the individual coils are not faulty because I switched them around and the misfires did not follow. If there is another coil in the circuit that powers the rest, it would be helpful to know where it is so I can examine it. Also, do you think the wires could be repaired? I know how to repair wires, but I'm concerned about finding the proper materials to do so. If the proper splices and repair wire are available for purchase, would you be able to direct me to where I might purchase them?

Thank you so much for your help.

Those are the only coils. You have eliminated that problem. I'm sure you have wire available for repairs, nothing special required. But it would be best to solder the splices and use heat shrink.

Thank you. You've been a great help.