Replacing an Ignition Amplifier for 1985 Jag XJ6
 

Does anyone know what kind of a job it is to replace an Ignition Amplifier on a 1985 XJ6 4.2 Liter Series III?
I had some work done at a dealership and the car died when my wife was driving it home. After it was towed back to the dealership, they said they could find no problems, it started up and worked fine. They said the only thing they could think of is that the Ignition Amplifier MIGHT need to be replaced, however, it is working fine at the present time and they cannot guarantee that replacing it would solve any problem. Instead of spending $700 for them to put a new Amplifier in, I am considering driving the car home and if I have any additional problems, changing the Amplifier myself.

The car has only 24,000 miles on it and is in "as new" condition. The problem is it has only been driven about 200 miles in the last 20 years and that's to and from the dealership to have the gas drained and have it restarted.

As you can probably tell, I'm a new member to this forum. I have owned 6 Jaguars in the last 40 years. Currently own a 2011 XJL Supercharged and the 1985 XJ6 4.2, which I bought new in 1984 and am saving for my grandson.


Reclusive Jag Owner

The ignition amp is one of the easiest things that you can replace...
I'd imagine most of their charge was in the unit itself, which can be found other places for less. The one on the car can also be rebuilt fairly easy, if you wish to do so.

It's really just three wiring leads to take off/replace (2 on the coil and 1 coming from the distributor) and two bolts... Quite simple...

Cheers,
David
Everyday XJ

Thanks. That's just the info I needed.

Amplifier is an easy fix.

I had similar symptoms recently - luckily enough I have a spare xj to swap parts around to trace the fault which ended up being the pickup in the distributor.

Again, a fairly ease fix which can be done without taking the distributor out (although it is easier with dizzy removed).

I highly doubt you need to even replace the ignition amp, those can easily cost $300-$400 anyways! All you have to do is open up the electronic ignition amplifier and replace the ignition module inside with an AC Delco ignition module and those can easily be found for literally a few bucks, Way cheaper and basically just as easy. The ignition module is the part of the amp the fails almost every single time.

Another route you can go is replacing the distributor with a pertronix aftermarket distributor, it has the ignition amp built in and costs less than a new amp anyways (about $170 off amazon) with that you get increased horse power better fuel economy and a smoother idle. its a little more work and a little more money, but worth every penny.

Sorry for the late thank you. You are the second person to mention the distributor situation. I will have this checked out, also. Sounds to me like the Petronix distributor would be the way to go. Then I would be addressing 2 potential problems at the same time.

Thanks again for the timely information. You guys are great!

Reclusive Jag Owner

Yeah I always suggest the pertronix distributor, its definitely the way to go in my opinion. the part number is pertronix d177600 hope that helps =)

Thanks for the number.
I contacted Pertronix tech yesterday and their answer may be helpful to others.

We do offer a distributor for these applications up to 1987. The part number is a D177600 for a 12 volt negative ground system. Also you will need to use our coil part number 40511 with his conversion.

Thank you,
Tech Dept

Thanks again

well... the pertronix coil is great and I do suggest buying one with the new distributor... but just so you know the distributor will work with any compatible coil, it dies not HAVE to be pertronix. I know "sales" and the pertronix tech is just trying to make a suggestive sale for the extra buck, great tactic, but its not entirely honest. I just want to make sure everyone on this forum knows that the d177600 pertronix distributor will work up to par with whatever coil you had on before as long as your coil is in proper working condition.

Thanks,

Good to know.

Sorry for the simple question, but what do I need to do to swap out the distributors? Do I just loosen the clamp bolt and slide the old one out or are there is there another bolt or 2 I need to remove? Any other tips?

I've got my Petronix set on order, but haven't got it in yet, and will be installing myself.

Thanks,

Eric

There is only one distributor, (made by Lucas) and once you have loosened the clamp bolt, it just pulls out. You may have to remove the drive connection at the bottom and put it onto your new distributor, unless that is sold for the XK engine.

Sorry for the confusion, when I said distributors (with an "s") I just meant the old one (Lucas) to the new one (Petronix). I realize there is only 1 on the XK engine. I've got the air cleaner out of the way and ready for the swap. Just need my new parts in hand.

Thanks for the help on what to do.

You only need to loosen the clamp, there are no extra bolts. And you will not need to remove the old drive mechanism, the Petronix drive fits perfectly. Also it is offset which is nice it will only fit in one way so you can't get 180 degrees off. Just make sure you mark the exact location of the old distributor with a grease pen or something, also the position of the rotor, that way you won't throw your timing off. And remember, bypass the ignition module, just connect the two wires directly to the coil. Best of luck to you!

I just wonder if you'e been happy with Petronix distributor (over the past 5 years!)?