'99 XJ & MSD Ignition...Where do I put it?

OK, So I've ignored all the advice about negligible performance or mileage gains with replacing the factory ignition & coil and went ahead and bought an MSD 6a and Blaster 2 coil anyway. (Already replaced the wires & plugs). Coil location and wiring won't be a problem, but I've scratched my head several times under the hood looking for the best mounting point for the ignition. If someone has any suggestions, please let me know. Thanks!.

doesn't the 99+ Cherokee use coil on plug setup. So I am wondering, did you just get rid of the factory system? I know my 98 has a coil, distributor and wires. I didn't know you could do that on a 99.:huh:

Coil, Distributor and wires on mine. The distributor-less setup is only on some.

Coil on plug started in 99 on the Grand Cherokee, and migrated to the XJ and TJ is 2000.

I made a bracket and mounted mine to the hood. upside down.

Put it in a accesiable location because your gonna wanna take it off again and soon...I know I did it to my 91 the problem is you start going thru plugs like mad with the msd box and the coil its just too much juice and they wear fast(check your gaps after about 3000 miles)...O and make sure you can splice back into the stock wiring so you can go somewhere when all the resitance finally nukes the msd box..I went through 2 and finally went back to stock and sold it to my in law for his cj5 now that made a huge difference for him...
I anchored mine to the fenderwell on the passanger side after making a mounting plate for it...
good luck
themud

I'm wondering if the Bosch +4 plugs might not be a bad choice here due to their multi-contact and platinum design???? :dunno:

themud said:

Put it in a accesiable location because your gonna wanna take it off again and soon...I know I did it to my 91 the problem is you start going thru plugs like mad with the msd box and the coil its just too much juice and they wear fast(check your gaps after about 3000 miles)...O and make sure you can splice back into the stock wiring so you can go somewhere when all the resitance finally nukes the msd box..I went through 2 and finally went back to stock and sold it to my in law for his cj5 now that made a huge difference for him...
I anchored mine to the fenderwell on the passanger side after making a mounting plate for it...
good luck
themud

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I mount my msd6a box on the passenger 1/4 panel between the battery and the firewall.

crystalship1 said:

I'm wondering if the Bosch +4 plugs might not be a bad choice here due to their multi-contact and platinum design???? :dunno:

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Horrible idea if you call msd directly like I did they do all their testing using just regular ol champion plugs(ie no truckplugs, plats, or +4s or anything else) thats what I ran and they did great for as long as they lasted...
themud

Wherever you put it try not to drill too many holes so that you won't have to plug anything when you go back to stock. I like the idea of fabbing up a bracket taht you can attach to existing fender or firewall screws... Try to leave the factory connectors on too and do any splicing on the msd side, again, easier going back.

I've been running the MSD box/blaster coil/and 8mm wires since 2000. I've found that overgapping the plugs (the entire reason I did it) won't allow me to run the bosch+4 or other pre-gapped plug. I run the single electrode bosch platinum overgapped to .045. They last the longest and I have tried many non-platinum plugs and went through them all very quickly (<5K miles).

BTW, I installed my MSD box between the battery and firewall on the passenger side 1/4 panel.

Later,
Rough

Gotcha.

I suspected that the platinum might help as they last longer in standard systems.

How long do they last and what kind of MPG and/or performance increase do you see?

Rough 01 said:

I've been running the MSD box/blaster coil/and 8mm wires since 2000. I've found that overgapping the plugs (the entire reason I did it) won't allow me to run the bosch+4 or other pre-gapped plug. I run the single electrode bosch platinum overgapped to .045. They last the longest and I have tried many non-platinum plugs and went through them all very quickly (<5K miles).

BTW, I installed my MSD box between the battery and firewall on the passenger side 1/4 panel.

Later,
Rough

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I've never had to replace a platinum plug due to wear from my system. I've always replaced them due to wanting to try something different. The longest I went any one set was ~20K and they still looked good.

For mileage I'm getting around 18mpg highway and 13mpg in town when I'm really getting on the skinny pedal. Just a note, I'm running 31x10.50x15 mud tires with a roof rack and 31" spare on the roof rack. I've also switched from a K&N cone filter to a high air intake(through firewall on drivers side). I put in a K&N flat filter in the stock airbox but still lost about 1mpg. I did that mod because I hated cleaning it after "every" off-roading trip.(dry=dirty, water=wet, mud=......you get the picture) Now the air filter stays clean and I'm sure the money I save from not buying all those K&N recharge kits will make up for the 1mpg.


Later,
Rough

I originally had mine on the inner fender behind the battery as well untill i hooked up the cruise control. I then moved it to above the windshield washer bottle. You will need to check the clearence when closing the hood. This is on a 96. I do not know how much roon the new bodt style has.

Mike