After searching the forum, I was unable to find anything related to my current problem while installing an MSD "Offroad" ignition module on my 4.0. Last year I did some head work, new cam, 6-1 Borla header, machined out my t-body, "revoltaged" my map (thanks guys!) and a few other tidbits on my 92 4.0. The folks at Clifford reccomend the MSD ignition module to give a little more fire (with MSD coil). Got the module, but have a few issues to contend with.
1. This module seems to replace the existing ignition completely, thereby negating advance curves, retard from knock sensor etc, is this REALLY a good idea?
2. My 4.0 has the (dread) LUCAS disty, and thus has three wires coming out of the pick-up. The MSD only has two to pull from (violet and green for +/-) anyone know which ones on the disty I should use?
Anyone with some experience with this, I would be very appreciative. I do have a couple other quick questions while I am on this. The reason for this is just not really getting the kick I was hoping for out of the new head. My fear is I have slowed the intake charge down through opening up the intake route to the point the gas mix is not turbulent, and thus not burning efficently. I understand the MSD can help, but then so can a blower and/or the stroker 4.8/5.0 kits. Anyone with any advice in this respect? How about taking more than the .020 off the head? All I did was a light surface of .020. Should I do more? How much more is advised (I did not search on milling heads, but will do so). Thanks for any advice.
Jeff :evil:

Clifford may have a good reputation for carb'ed I-6 but I have not seen or heard ANYTHING coming from them regarding the EFI engines. In fact, I've heard others who have been told that MSD systems are good on a 4.0L. (curious, did you buy yours from them?) Most people (much more technically qualified than I) have stated that MSD systems are of NO benefit to the 4.0L engines. FWIBT, the stock ignition system is more than adaquate for the 4.0L engines.

When I was researching my stroker build, someone at Clifford gave me a bunch of mis-information and tried to convience me that I could get more HP from a carbed 4.2 (their 6=8 built engine @ like $4,200) and therefore would be a better build than a EFI stroker for a crawler. I'm not saying he was wrong about squeezing more HP out of a 4.2 but at that cost I could build two strokers or drop in a crate motor.

It is somewhat sad. They had a great name back in the 70-80's. Hate to see their head in the sand.


As for the 4.8/5.0L stroker, I had someone tell me they had a 5.0L stroker built using a 4.0L block. I bet him $400 that IF it started, it would grenade within the first 1,000 miles. He really talked a bunch of shit until they tried to start it. Never heard from him again. Wouldn't return emails. Unless you want to put $5,000 - $8,000 in a I-6, you won't make it much further than the guy above. Stay with a low compression stroker and add a supercharger if you feel you need it.

Do more research before bending over next time. Unless you like it like that. If you do I suggest JU. :flipoff2:

i have an msd 6a and blaster 2 coil on my 96 xj 4.0/aw4, i know apples and oranges ( carb vs efi ) but i can recommend this mod highly !!
bear in mind this is a daily driver with other mods also, i was looking for better throttle response and wound up gaining 4 mpg on the highway.
at the time i was driving 75 miles one way for work ,and gas $ was killing me
so i was thrilled , after install it would get second gear/full throttle upshift.

so dont give up yet ,well worth the hassle. :smokin:

Do you recall how you hooked up the 6a? Does it completely eliminate the stock ignition timing logic? It seems it would if it is hooked up the way they specify to do so. So far, MSD has been little to no help, and Clifford has been mediocre at best.

the msd box hooks up to the wires going to the stock coil , not dist.
\cam sensor is inside the dist. crank sensor in bellhsng is for ignition.

cant remember which one was +/- , i will look at the wiring diagram when i get back to work, and post later tonight.yours is a 92 right ?

i had to hack the connector off for the stock coil , and splice into harness .
did yours come with an install manual ?
mine did but it did not match the "jeep" diagram , called msd - they said to use the dodge example ( input to 6a from stock coil input )
this still keeps the computer in the loop for advance /etc.
btw- voltage to coil from msd isnt 12-14 volts , stated v is like 400 !!!
have not tested this but i know it will knock you across the room if you get zapped by it !!!!!! dont ask how i know . :smokin:

Excellent! So I am basically going to fit in between the original connection to the coil and the coil. THis makes alot more sense than what the diagram says. Yes, mine is a 92. Thanks again!

exactly , solder connections and use shrink tubing if available .
dont want corroded connections when nut deep in a mud hole !!

the fsm was useless for wiring color , so i went into alldata .(slow day at work )
for a 92 xj , orange wire is ignition positive + , grey wire is coil driver -
if i remember right that was similar to my 96 .

oh yeah , throw the pos stock coil in the trash .
and upgrade to some platinum plugs , i have had good luck with the bosch
platinum +4 , pricey but little or no wear after 30k miles.

enjoy !!!

Excellent! I should get to it mid-week. Thanks again.
Jeff