can I replace the stock coil with a MSD coil on 91 4.0
not a box just a
MSD Blaster 2 High Performance Coil 8202

 

Your stock coil is more than adequate. You won't see any performance gains from the MSD coil.

 

but if it works out you could see mpg gains

 

i'm not tryin to rain on any parades but unless you are full out mod on the engine. it does no good to do little things like this. it causes problems for the other components in the ignition sytem. they are designed to operate all together at specific voltages and variences. the one high power component could overpower the other items down stream causing premature failure.

 

X 2. I agree with Throttle Jockey!! I believe the OEM electronic ignition on our 4.0 liters is pretty darn hot. I say use the money for more gear to make your XJ more capable offroad.

 

the MSD Blaster 2 High Performance Coil 8202
works great it was something left over after we did a HEI distributor on my sons 383 stroker motor
with very little work the stock coil works just as good but if you ever need to use one in a pinch it works

 

I already gave you my opinion on that subject Mike. You need to shoehorn that 383 into your XJ and call it a day.

 

a Aftermarket MSD IGN box like a 6al/7al needs to be used to get the full voltage the coil is capable of.

 

I cant afford the gas to run the 383
its really should be just a drag motor
we could re cam it but for now its parked

 

After finding this crack in my coil, I replaced it with a new one from NAPA. My Jeep starts better and runs a lot better. I wouldn't be concerned with using an MSD coil.