[cher96]

I am confused as to what I need to redo my Ignition system.

I want to go with MSD Offroad Ignition however one site said it fits my 96 XJ Country 4x4 4.0L truck and another said it didn't.

Plus, do I need a Rev Limiter?

What wiring harness do I need?

The MSD coil is easy. The Cap, Rotor, and Wires are easy.

Has anyone installed this system. If so what products are you using and what do I really need to get.

I'm replacing everything. Thanks.

 

[mecompco]

Do you have a stroker with all the other performance mods? If so, I think it would be a good idea (you can run your plugs with a bit more spark gap). If not, it is pretty much a waste of money--the OEM replacement parts will give you all the spark a stock 4.0 needs. The ECU has a rev limiter built in..

 

[cher96]

I have:

K&N 9" cone filter
Exhaust header
2.5 CatBack Exhaust
8.5 MSD wires
Stock Coil
High performance plugs (100,000 mile)
3 row radiator (all metal)
Oil cooler
trans cooler

All on my '96 XJ

I would like to go with a stronger Ignition because I was told my spark was a bit weak yesterday by my friend when he checked it for me.

 

[alexrule123]

I would like to go with a stronger Ignition because I was told my spark was a bit weak yesterday by my friend when he checked it for me.

How did your friend determine your spark was weak?

 

[cher96]

He took a SP wire and used a screwdriver and put it to a ground and watched for the spark while I cranked the engine. He said it was way too weak.

 

[alexrule123]

He took a SP wire and used a screwdriver and put it to a ground and watched for the spark while I cranked the engine. He said it was way too weak.

Well the stock coil is enough to run a gap that is .070" (that is what I run) so as long as your coil is good then I doubt your spark is too weak.

 

[cher96]

Also, I will be putting in a stroker 4.9 / 8.1 Compression from Titan in October. My step dad has friends there and I thought I would get ahead of myself since another person said I had to replace the ICBox.

My XJ is an all around trail XJ: Rock, sand, mud.

 

[alexrule123]

I can't really comment about needing it for the stroker since I don't have any first hand experience with them.

 

[4.0H.O.XJ]

The WEAK LINK in the 4.0's ignition system is NOT the coil. In fact, the stock coil is more than adequate. What IS the weak link is the aluminum-terminaled distributor caps that Auto Zone/Rogers/Pep?Kragen cheap chain store dist caps. Copper or Brass terminal distributor caps will always give a stronger spark signal, as it is a much more conductive material. You will never pull a brass-terminal dist cap and see white fuzz on the terminal ends where the rotor tracks like you do with an aluminum one.

Get the MSD cap and rotor, (they have brass terminals) get the good wires, LOSE the "high Performance" plugs (they do not run right in 4.0's) and go get a set of champion truck plugs or autolite 3924's as your engine will live happier with them.

Your friend's method of checking spark cannot give you an indication of much voltage is passing through the system, and is only a basic bench test to see if there is any spark at all in cases of no start. Intermittent visible spark could be any number of things when testing this way. All he REALLY verified is that there is indeed spark. How much and where the weak link is anybody's guess.

Back to coil, IMHO, you are pissing money away on that. To quote Ed A. Stevens from another XJ-specific site:
".......The ignition on the 4.0L is very good. The system can be improved with a high altitude CPS to allow advanced timing. The RENIX system has the advantage of the knock sensor so going too far and promoting ping is not an issue. Good plug wires and cap/rotor help, and the stock E-coil is better than most factory systems up to 96. An MSD-5 or 6 will help a tired motor, and areas with poor fuel (rual Mexico), but is NOT needed for most users....."

Not to get too long winded or piss in your Cheerios, and if you are under 30 and/or in college, it is understood that you are going to do it anyway regardless of what anyone tells you.....but from a mechanic's standpoint.....a good (brass)/copper) premium cap and rotor combined with the proper plugs and good wires will make your XJ most efficient and provide MORE than enough voltage for your ignition, more reliably. Your upgrades are a good start and admirable, but nothing dramatic enough to warrant that type of ignition set up.

Just trying to save you a few dollars, bro.

 

[cher96]

I really appreciate your thoughts. :thumbsup:

I am a 51 year old woman who is building this XJ for my 16 year old son.

I will buy the MSD Cap and rotor if they have one

or

an ACCEL brand

Brass or Copper as you suggested. I have NAPA cap and rotor now.

I have 8.5 MSD wires. I don't think I will need to replace them. only 6 mo. old.

I will change out the plugs and gap them wider.

Thanks :cheers2:

 

[alexrule123]

The WEAK LINK in the 4.0's ignition system is NOT the coil. In fact, the stock coil is more than adequate. What IS the weak link is the aluminum-terminaled distributor caps that Auto Zone/Rogers/Pep?Kragen cheap chain store dist caps. Copper or Brass terminal distributor caps will always give a stronger spark signal, as it is a much more conductive material. You will never pull a brass-terminal dist cap and see white fuzz on the terminal ends where the rotor tracks like you do with an aluminum one.

Get the MSD cap and rotor, (they have brass terminals) get the good wires, LOSE the "high Performance" plugs (they do not run right in 4.0's) and go get a set of champion truck plugs or autolite 3924's as your engine will live happier with them.

I will second the autolite plugs, I ran some "performance" platinum plugs and threw them away after 100 miles because my jeep would miss like crazy after 3000 rpm with them. After I replaced them with the autolites I had zero missing. The accel tune up kit I got had a cap and rotor with brass terminals so that is another route you can take.

 

[cher96]

Thanks people.

I will put in a new MSD coil, too.

I had an Accel Super Coil in it and had to take it out because it had a huge crack in it. Put in the stock coil. That was 2 weeks ago.

 

[nrpalmer32]

Does anyone ahve the MSD Cap/Rotor part number(s) for an '87 4.0 by chance?

 

[cher96]

I found this pdf:

http://www.msdignition.com/uploadedFiles/MSDIgnitioncom/Products/Accessories/8889_instructions.pdf

 

[alexrule123]

Thanks people.

I will put in a new MSD coil, too.

I had an Accel Super Coil in it and had to take it out because it had a huge crack in it. Put in the stock coil. That was 2 weeks ago.

Yeah my accel coil crapped out on me too.

 

[cher96]

MSD recommends this, however, the review is terrible.

http://www.msdignition.com/product.aspx?id=5811

 

[BrunoS]

i have an MSD coil #8228, works fantastic.

i agree on the autolite 3924 old school plugs.

NAPA used to sell "blue streak" caps and rotors, those were solid brass and are bulletproof. well worth the extra $5 total between chinese/mexican cheap autoparts and USA made bluestreaks.

for a 96', be shure to drop in a new $12 fuel filter...engine will run like new..and will ensure correct pressure and fuel volume for best injector spray pattern...a bottle or two of techron helps in injector cleanup as well.

and get rid of stock muffler and weld in a magnaflow muffler. it's worth a proven 5 hp, 7 ftlbs torque (no BS), and about 1-2 mpg.

34-35 psi in tires helps mpg and power as well.

 

[cher96]

I'll put in the MSD coil, brass or copper cap and rotor (both the same material) and new plugs.

 

[4.0H.O.XJ]

Cher,

You sound like a great Mom, building your son a Jeep. Hope he is getting dirty underhood with you.

You are on the right track, though I personally feel MSD is overkill, being a 1996 it's probably time for a new coil anyway, and the extra spark cant possibly be bad considering you have a 12 year old coil there.

Go for it. Get the MSD kit. Change those plugs, though.