Hello all. Im am new to this website but have already referred to it many times in searching answers for my jaguar. I bought my 1990 xj6 about 6 months ago. It is my first jaguar and I love it! I bought it from the second owner. Everything on the car works and it is in great shape. It has 87,000 miles on it. After a quick inspection it is easy to see that everything on the car is original. Things lime fuel filter, plug wires, coil etc. The self leveling system had already been removed so I put new shocks on the front and back. Anyways to my question.
I am gonna do a ignition tune-up and im good on the plugs, wires and distributor cap and rotor. I would like to add a MSD 6al box and blaster 2 coil. I have done this with other vehicles but wanted to see if anyone has experience with this on this car or any suggestions about it. I just wanna make sure im good to do this upgrade on the car. Should I upgrade anything else on the ignition so I dont burn something up with the extra voltage and power?
Any help would be much appreciated as I want to do this asap! Thanks

 

Hi clickslincoln,

Welcome to the Jaguar Forums! It's great to have you with us.

I assume the reason you would consider adding an aftermarket ignition to your Jaguar would be to improve the performance of the engine. Before you attempt to make that work, you might study the AJ6 Engine Management System manual to understand how the Engine Control Module (ECM) manages ignition timing and how the ECM and Transmission Control Module (TCM) work together to manage shift points and shift quality. You can download the manual free at the link below, courtesy of our forum member Gus:

http://www.jagrepair.com/images/Auto...stem%20S91.pdf

Also, check out the items developed by AJ6 Engineering in the U.K. to increase the performance of the AJ6 engine. You'll see that they have an intimate knowledge of the AJ6 engine and their methods for improving performance center on getting more air into and out of the engine. I don't recall that they consider the ignition to be a limitation, but I may be wrong:

WELCOME TO AJ6 ENGINEERING / AJ6 Engineering

While I'm thinking about it, note that many longtime XJ40 owners have found the stock Champion RC9YC / 344 spark plug to be just fine and very reliable, and attempts to use fancier, more expensive plugs have produced mixed results. To my knowledge, no owner has reported any significant performance gains by using a plug other than the stock Champions.

One simple modification you can easily make is to enlarge the air intake nozzle on the air filter housing. Here's a link to how I did it:

Welcome to Jag-lovers - Members Photo Viewing Page

Also, check out this thread on XJRengineer/Andy Stodart's revised mounting bracket for the Crankshaft Position Sensor (CPS), which advances the ignition timing by 5 degrees (I think). I don't think Andy's bracket will fit your '91 engine because it won't center the CPS on your crank reluctor/sensor ring, but check with Andy to be sure. If you're handy, you might be able to fabricate your own bracket design. I fitted Andy's bracket to our '93 and it not only gives the engine more mid- and high-end responsiveness, but it improved the fuel economy by nearly 2 mpg:

https://www.jaguarforums.com/forum/x...engines-66536/

Andy can be reached at andystodart@metronet.co.uk

Also, since we're a friendly group, please visit the New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum and post an introduction so we can learn something about you and your Jag and give you a proper welcome.

Cheers,

Don

 

Thanks alot don. Alot of good info. I will check out everything you posted here for me.

 

Clicks,

You'll gain just about zero by installing an aftermarket ignition system, MSD or otherwise. The stock system is more than capable of getting every last ounce of energy from the fuel.

The MSD systems can be of help on high performance engines where the stock ignition system is weak or otherwise can't keep up. Those type of systems pretty much disappeared in the 70s when high powered HEI or similar appeared.

Save your money.

 

Thats also why I was asking. To see if anyone had experience or if it was worth doing. Thanks.

 

Kind of off topic but I knew a few people that did that on their Turbocharged Volvos for better performance. I stuck with the stock stuff and was more than capable of destroying multiple transmissions and rear ends without using MSD.