i want to buy a multi-spark unit for my...xj-4.0--1989
and i need your guys knowledge for this one.....
brand?
name?
model?
i am looking for the best bang i can get on a budget
thank you again
and again weekend it's here

Save ou money friend. The output from the coil in you heep is more than adequate. increasing the coil output can lead to detenation and that is never a good thing. A good quality sparkplug gapped correctly will be your best bet. Even opening the gap .005" will help a bit.

x2^

Sorry Frank gotta disagree.
after being into racing in a big way everything from my harley to my sled to my racecars to my winter beaters all got updated MSD' or even at least a hi output coil. Anything that can make your spark hotter and longer WILL make your fuel burn better getting all the energy out of that $3.00 a gallon gas burn better.
If you want more info on how to improve your spark just ask.

An increase in coil power will not lead to detonation.


Detonation is when the fuel/air mixture is "self combusting" because of too much compression or too early of an ignition advance.



In a very loose sense ... the air/fuel mixture is "too efficient" for the engine setup, which is why high octane fuels came about. The higher the octane, the slower the rate of burn.



Joe