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Does this upgrade make that huge of a difference to cold weather starting? I am considering this in the future but am not sure of the improvement to starting is worth the trouble. I still have the stock system in mine as far as i can tell although I suspect my coil is aftermarket.
When I swapped mine over I did during reassembly.... like 5 years after disassembly. Needless to say, a direct comparison would be impossible at best. What I can say is with the distributor upgrade, MSD wires, new plugs, and the MSD6 box, I've never had a CJ run as smoothly as it does now. Only thing left to swap out is the coil, but even with the old stock coils it runs great. As to cold weather starting - I have a manual choke, and when it's 20 deg outside, with full choke and a half press of the skinny pedal, it fires right up. Like, immediately. Never drove this one during winter months, but yes - cold starting is wonderful.
84 CJ7 4 banger-owned since new in 1984 bought off truck at dealership - rebuilding 258, T176 with Sniper EFI D300 4:1 Lomax gears Twin Sticked 1 piece axels with locker
When I swapped mine over I did during reassembly.... like 5 years after disassembly. Needless to say, a direct comparison would be impossible at best. What I can say is with the distributor upgrade, MSD wires, new plugs, and the MSD6 box, I've never had a CJ run as smoothly as it does now. Only thing left to swap out is the coil, but even with the old stock coils it runs great. As to cold weather starting - I have a manual choke, and when it's 20 deg outside, with full choke and a half press of the skinny pedal, it fires right up. Like, immediately. Never drove this one during winter months, but yes - cold starting is wonderful.
Did the upgrade on my 85 CJ7AMC 258 i6 / 4.2l 3 years ago .... Wow. Yes there is a difference in the start, idle, run, and tune.
I went with the MSD Streetfire and high vibration coil.
Sure made for a simple setup.
'72 would mean a Delco Remy breaker points distributor so the Motorcraft/Ford parts won't work for you.
There are two ways to go about this, both take more than just cap, rotor, plug wire replacement and I-6 caps with brass terminals are scarce as winning lottery tickets now.
Without question, the MOST simple way to go electronic ignition is a Chevy I-6 HEI distributor.
The AMC camshaft gear *Should* swap right over to that GM HEI...
If you want to go one step further, '76 Chevy Blazer w/250 I-6 engine
Get the distributor and REMOTE coil, (HEI with a coil wire, coil off to the side of the distributor)
Swap the camshaft drive gear and run it, just keep an extra rotor in the glovebox.
Since the HEI wants a full 12 volts (battery voltage) you will need to locate and remove the ceramic block ignition resistor, but nothing else changes if my old memory serves me...
You will be surprised with the timing curve in the GM distributor, but don't ignore any engine knock (spark knock) and take a little timing out of the distributor if you get any knocking.
It's stupid easy to do with GM distributor since they put advance springs right under the rotor, and an adjustable vacuum advance practically falls into that distributor.
You can't swap in a Ford I-6 distributor, turns the wrong direction...
Just a tip in case you hear from the bunch over on other forums.
When people talk about caps, rotors, plug wires, negative current path of the engine heads ("Grounding"), it's all important...
It's about efficiency,
Generating as much USABLE spark energy as you reasonably can,
And delivering that spark energy to the gap in the spark plug where it does some good.
Losing the Limited amount of energy produced by the low voltage side of the ignition, and the transformer coil BEFORE it reaches the spark plug gap simply cripples the ignition POTENTIAL.
All this upgrade does is one of two things, 1. Delivers the spark energy to the plug gap more efficiently, more of what you are capable of producing with existing equipment gets to the plug gap,
2. Uses easily available, off the shelf parts to increase reliability.
Now, unless you have a master's in electrical education, some of this has to be pointed out since it's not common knowledge...
Brass is about 70% copper (30% zinc) very conductive,
But more importantly it's self-healing when high voltage plasma (spark energy) melts it.
It cools/heals the tunnels of molten material where plasma hits it.
Aluminum burns away, becomes electrically resistance, aluminum oxide.
This is why I don't use aluminum cap terminals, and if I'm forced to I change caps often...
Aluminum cap terminals & rotors *Should* be replaced every year or two no matter if you can see the damage or not, it's there...
In HEI ignitions you will see 'Red Dust' (welding slag with all the carbon burned out) where the cap terminals became so electrically resistant the spark energy burned through the rotor and tried to weld/blow out the steel.
It just makes sense to use a self healing material that remains highly electrically conductive.
Plug wires are a mess, so many were designed to save money than to deliver spark energy to the plugs.
Now, you must consider some plug wires are so inefficient they interfere with electrical communications like TV & radio.
That's all lost spark energy...
A good set of plug wires lasts a LONG time (I'm running some better MSD wires that are 20 years old),
And they still perform well, losing very little spark energy along the way.
Cheap wires will bleed energy like crazy, some of us older folks remember misting plug wires with engine running and seeing a light show,
Some others will have issues with engine running when wires get wet splashing though mud/water.
With a good set of wires/boots and a little maintenance, this isn't an issue.
My Jeep actually runs under water without the super expensive 'Water Proofing' on the plug wires.
This might not be an issue with desert crawlers, but here in the Midwest we have a lot of mud, deep water, etc.
I also build with an 'Expedition' vehicle in mind, not just an occasional jog 'Off Highway'.
If you truly go 'Off Road', as in NO ROAD of any kind, then having something as reliable as possible under all conditions is a rally good idea...
Not everyone is going to run two ignitions (and two fans, two fuel pumps, pressurized drive line to keep water out, etc), but when you think 'Expedition' and being 100 miles from the nearest parts store,
Then it's a pretty good idea to carry your 'Spares' already hooked up and working, ready at the flick of a switch.
Stuff needs to assess their application,
The three rules of what *YOU* need are,
1. Application.
2. Application.
3. Application!
I don't expect everyone to be an EE (Electrical Engineer)...
Electrical Resistance, Impedance, Capacitance, etc isn't what every Jeeper needs a 4 year degree in,
All most want to know is how to get the damned thing working as designed.
Then there is a 100 years of myths to overcome,
That ignition coils 'Store' energy, that aluminum is as good of an electrical conductor (in this application) as copper or brass, that high voltage is the only thing that matters, etc.
The ignition coil (transformer) only has 'X' amount of MAGNETIC field energy to work with,
The transformer 'Stores' nothing, it immedately converts magnetic field energy to electrical energy (electro-magnetic link),
And you spark kernel in the plug gap has 4 major components based on TIME...
The first part of the spark innthe gap is ionization, the gap MUST ionize to support the full on spark kernel.
This takes time, using up some of the energy the transformer is producing.
The second part is VOLTAGE, enough voltage for arc to jump between electrodes (gap).
This voltage doesn't need to be excessive...
The third part is AMPERAGE, how 'Hot' the spark kernel gets, this determines how hot then plasma ball gets to ignite the fuel/air (charge) mixture.
The fourth part is DURATION, the TIME the plasma kernel STAYS in the spark gap.
That's a LOT of energy need to keep a well formed, long duration, hot plasma kernel in the gap from a transformer that has an energy conversion TIME of milliseconds...
Finding a BALANCE of how that energy is used, along with NOT giving most of it away making magnetic fields, radio signals, light shows, etc is what I aim to do...
After all, the idea is to get the spark kernel formed, and keep it there long enough to reliability get the charge mixture PROPERLY burning,
And without requiring an engineering degree, using mostly factory type parts to do it.
No one has an unlimited budget, or has an unlimited shop to work in!
I have 60 years of experience in working on 'Junk' and making it (somewhat) useful, if I can help I will.
84 CJ7 4 banger-owned since new in 1984 bought off truck at dealership - rebuilding 258, T176 with Sniper EFI D300 4:1 Lomax gears Twin Sticked 1 piece axels with locker
I’m bettin if someone would come up with an evaluation method to check our knowledge after reading his posts, it would be equivalent to a BS. Knowledge with practical application in real world situations...... PRICELESS.
Well, it's pretty simple,
The primary windings in the transformer coil build a magnetic field.
With the common 12 volt systems, the magnetic field can only be so strong, and you have to choose if you want high voltage with a wide plug gap,
Or you want Amperage/Duration (Time) with a smaller plug gap.
If the coil spends all it's energy and time building Voltage, the duration & amperage suffers.
Once the system converts the magnetic energy to electrical energy, then you should probably decide how much you want to get wasted on the way to the plug gap, that's rotor, cap & wires.
Without all the technical jargon,
A reasonable plug gap, a compromise between voltage, amperage & duration.
A really conductive set of wires that doesn't waste the Limited energy the transformer can produce from 12 volts,
A cap/rotor that doesn't waste/scatter the spark energy, gets it where it's supposed to go,
And components that are a little more expensive on the front end, but do the job much better, and live longer than the factory stuff.
The wider/taller cap/rotor keep the increased spark energy from an electronic ignition going where it should go.
Brass terminals self heal and continue to be conductive well past the point where aluminum terminals would be toast,
The wider spacing prevents cross fire & 'ground' fire inside the housing,
The better spiral wound conductor cores transmit the energy MUCH more efficiently, silicone/doubled insulation are heat resistant, chemical resistant, don't dry rot like vinyl/rubber does, it's all around a better way to do things.
Let's not forget the better terminal ends & boots that make the wires very long lived.
It's money well spent.
Then it's a question of a good spark plug, and getting it gapped so you have a reasonable compromise between voltage & amperage to take best advantage of the available energy.
0.035" to 0.045" is usually a very workable zone...
*IF* you have some advanced tuning equipment then you can narrow things down even more.
Something as simple as a vacuum gauge & an accurate tach can help some...
It's all in how you want to do things, and the computer tuners have no idea how to do this stuff, it's us old farts that still know how to do it...
84 CJ7 4 banger-owned since new in 1984 bought off truck at dealership - rebuilding 258, T176 with Sniper EFI D300 4:1 Lomax gears Twin Sticked 1 piece axels with locker
I know you said / wrote you worked at MSD back in the day, and that quality may not be what it was, ( don't want to put words in your mouth ) but that is what I have in my Jeep. Is there a plug you would recommend over what Jeep recommends for the AMC 258 i6 / 4.2l ?
Keep in mind you can NOT see a magnetic field with the naked eye,
Science deniers won't understand this because they can't see it in operation,
But study the electro-magnetic link...
EVERY electrical current produces a magnetic field.
That magnetic field spins around the wire (conductor).
That magnetic field is lost energy as it's spun off into space.
(And creates Electro Magnetic 'Noise', all energy goes somewhere, not necessarily where you want it to go)
Using a spiral wound wire (see the pictures of spiral wound wire cores in OP's picture) spins some of its magnetic field back into the wire next to it in the spiral, so it preserves more of your spark energy without creating so much EM noise.
It's not a 'Super Conductor', but it's also not a million dollars an inch or has to be super cooled...
Now, the other half of the electro-magnetic link is,
When you pass a magnetic field through an electrical conductor, it creates ('Induces', Induction) an electrical current.
This is the way your generator/alternator/ignition coil works (and every transformer).
The 12 volts from the battery passes through the PRIMARY winding in the ignition transformer (coil) and builds a magnetic field...
When that circuit is opened, the magnetic field collapses onto the ferrous iron core, passing through the SECONDARY (high voltage) coil/winding...
The magnetic field moves, passes through the copper winding, and that INDUCES the high voltage discharge.
You only make high voltage for the milliseconds it takes the magnetic field to collapse, so TIME is very Limited .
You can drive the voltage up with a wide plug gap, which robs you of Amperage & Duration (time),
This results in a weak, 'Thready'/thin, short duration spark,
Or you can close up the plug gap some, and put some of the spark energy into amperage, making the plasma spark kernel much hotter in temperature.
When you see the difference visually, it's the difference between a 'White' thread in the gap that makes a quick 'Snap', sometimes the spark is so weak & fast you can't actually see the spark, just hear it...
And a blue spark kernel that makes more of a protracted, sizzling 'Pop'.
This is of course a line voltage ignition, usually around 12 volts, with a single discharge...
We aren't talking a CDI that will charge the coil with 600 volts, and recover fast enough to fire the plug 5 or 6 times.
CDI units give you an automatic 500-600% increase in spark energy applied to the fuel/air mixture simply because it is fast enough to fire the plug 5-6 times (at lower RPM, usually under 2,500 rpm).
Since most of us crawl at under 2,500 rpm, a CDI unit is particularly useful, getting the cylinder fired under load at low RPM which is difficult....
Capacitive Discharge Ignition (modules) are an entirely different animal from line voltage/single fire ignitions,
While VERY useful, not entirely necessary if you get your 12 volt ignition firing correctly.
One good thing about 12 volt ignitions, they have been used by every manufacturer since 1975, and a ton of the different components work together, so you are never really 'Stuck' once you learn how to mix & match parts.
Any salvage yard or parts store will have something that will get you on the road...
I have two (dual) ignitions, and the secondary/backup will always be off the shel, common parts for this very reason....
In fact, if you have read my write ups, you know I go with direct replacement parts, things that swap directly on.
Some minor connectors might need to be changed, but a few twisted wires will get you out of a 'Stuck/broke' and back on the trail...
Every junk yard is full of Ford caps, rotors, coils, modules, same with GM stuff, and in a pinch I'll go with Chrysler,
Just what ever fits the application best...
Every parts store carries the aluminum terminal stuff if you need it, and it will get you home, if not 'Optimum'.
I don't need a 20,000 RPM roller bearing distributor in a 4,500 RPM Jeep,
What I need is something that is efficient, easy to work on, and lives a LONG time so it doesn't cause problems.
And we are back to... APPLICATION...
I know you said / wrote you worked at MSD back in the day, and that quality may not be what it was, ( don't want to put words in your mouth ) but that is what I have in my Jeep. Is there a plug you would recommend over what Jeep recommends for the AMC 258 i6 / 4.2l ?
I finally upgraded my ignition. Actually I did it a week ago. I decided to go with the TeamRush upgrade. I'm glad I did. It consists of upgrading the distributor cap and spark plug wires. This upgrade makes sure the spark energy goes where it is intended, to the spark plugs. With the smaller OEM distributor it is possible to get cross fire in the distributor where a spark goes to the wrong cylinder or a spark going down to a ground. Once the distributor was upgraded I installed a MSD series 6 ignition module. DO NOT install a high performance ignition module without upgrading the distributor. The OEM distributor has a hard enough time getting the spark to the correct spark plug.
Coil Replacing the coil is optional. The TeamRush upgrade allows you to either keep the stock coil or replace it with an after-market. I already have a MSD Blaster High Vibration coil. My last coil shorted out and it may have been from getting bumped around off-road. Most coils are oil filled. It is possible for the wires inside the coil to bump around and short out. The MSD Blaster High Vibration coil is epoxy resin filled and can handle more banging around. Also it doesn't need to be mounted upright.
I prefer canister coils. They offer stronger, high current sparks at low rpm.
Distributor Cap As long as your CJ was made after 1977 you have a Motorcraft Distributor. These distributors can benefit from a larger distributor cap intended for a ford.
I bought the MSD Ford V8 Cap-Adapt kit for $36. (MSD Part 8414)
If you want to save a few dollars and get an OEM distributor cap just make sure it's good quality with brass terminals. You can get a distributor cap, rotor and cap adapter for a stock 1980 Ford F150 with a V8. The cap adapter fits over the distributor but flairs out big enough for the larger cap to fit on.
If you have a strait six in your Jeep you can look up the parts for the same year Ford F150 but with a 300 strait six.
To install this Ford Distributor Cap, it just snaps on like it was meant for your Jeep. No instructions necessary. (Actually it is a Ford Motorcraft Distributor in your Jeep)
These distributor caps have different terminals so you will need new wires.
Wires
I already had nice MSD wires for my OEM distributor but now I had to replace the wire ends at the distributor end. I bought the MSD crimp on ends. I cut the end off my wires and crimped on the new ends. The ends I got were MSD part 3330. These come with 2 in a package so I bought 5. (8 spark plug wires and one coil wire) This left me with one extra connector.
For everyone else that doesn't already have MSD wires you will need MSD part 5551 if you have a V8 or if you have a strait 6 you can get Motorcraft spark plug wires (part WR4050). These Motorcraft wires are ready to be installed.
These MSD wires (PN 5551) require you to crimp the ends on yourself. Trust me, it is very easy to do this right. The MSD wires already come with the MSD Mini-Crimper. The new style connectors use what MSD calls a Dual-Crimp. The connector has one section that crimps onto the insulation to physically hold the connector on. Then there is a smaller crimp section that only crimps onto the conductor part in the center of the wire. This part is crimped on with needle nose pliers. When I first realized I needed to use needle nose pliers I regretted not buying an expensive crimping tool. The first rule for crimping connectors is to use the right tool and never use needle nose pliers. Well, in this case needle nose pliers are the right tool. These connectors were meant to be used with needle nose. .
On the left is the new style Dual-Crimp Connector. On the right is the old style.
The first step is to cut the wire to the correct length. I then use the MSD Mini-Crimper to strip the wire. Put the wire into the correct hole on the Mini-Crimper/stripper. There are 2 holes: one for 8 mm wires and one for 8.5 mm wires.
I put the wire up to a marking for Dual-Crimp connectors. Then I use a razor blade to cut off through the insulation. This small section of insulation then twists off.
Next I crimpped the connector onto the wire. If you have the newer style Dual-Crimp connectors you will crimp in two steps. First crimp the connector to the insulation. To do this you will use a vise to do the crimping.
Once the connector is on the wire apply dielectric grease to the connector and press it into the boot.
Timing Advance Springs This part is completely optional. These advance springs are in the distributor. They hold the advance weights. I put in lighter springs to allow the timing to advance at lower RPM. I used Mr.Gasket #925D springs following the advice on JunkYardGenius.com. To get down to the advance springs remove the distributor cap. Next you have to remove the reluctor (trigger wheel) from the distributor. Some pry it off with 2 screw drivers but I found it very easy to remove with a small 2 arm puller.
These springs do not have to match. You can have one firm spring and one medium spring or any other combination. The springs work together to try to keep the weights from swinging outward at low rpm. When the weights are outward the timing is fully advanced.
The inside of the distributor can be cleaned with a spray can of electrical contact cleaner.
CDI Ignition Module The stock ignition system uses the inductance of the coil to produce the high voltage spark. To get the next big jump in ignition performance you can install a CDI ignition module. CDI stands for Capacitor Discharge Ignition. MSD makes some of the best selling CDI modules. You will want to get an MSD series 6 ignition module such as the Digital 6A, 6AL or the 6 Off Road. I got the 6A (MSD part # 6201). The 6AL is similar except it also has a built in rev limiter. The 6 Off-Road is water proofed.
I mounted my MSD ignition module on the passenger front inner fender. All the wires are plenty long. In most cases too long. I shortened the wires and re-crimped ends back on. If you are not comfortable crimping the wire ends just keep them full length and tie wrap up the extra. The MSD ignition module I got included an extension for the wires to distributor.
Others that have done this modification have recommended you keep the OEM distributor connector and not cut the wires in case the MSD module fails. That sounded like a good idea to me since I do a lot of four-wheeling on remote mountain trails but you will also have to reconnect the coil back up with the OEM wires. To do this you should also keep the wiring diagram in your Jeep so you will know how to uninstall the MSD ignition. I couldn't find an MSD wiring diagram for this application so I made one based on one of their other diagrams. The JunkYardGenius (JeepHammer) gets credit for the design.
The heavy gauge black and the red wires need to go directly to the battery or to the end of the battery cable. For example the positive battery cable connects to the starter solenoid on the inner fender. This is where I connected the large red wire in the MSD harness. I use dielectric grease on all connections.
Spark Plugs With the ignition system upgraded you can now run your spark plugs with a wider gap. I used Autolite Copper Core spark plugs. It's part number 65 for my V8. If you have a strait 6 get Autolite part number 985. These are the regular spark plugs intended for the AMC engines. Champion also makes good spark plugs. The plugs can be gapped to .045 to .050. Use the correct gapping tool. Don't use a gap measuring coin to pry open the gap.
When installing the spark plugs use copper anti-seize. Then when you install the spark plug wires use dielectric grease.
Next check the timing.
That's it! Now you've got better performance, gas mileage and easier starting especially in the cold. These mods don't have to be done all at once. You can do the distributor cap and spark plug wires alone.
Would you recommend installing an MSD on a stock or modified engine. I have a mildly built 383 stroker wit an HEI distrbutor. Would I benifite by converting to an MSD?
Would you recommend installing an MSD on a stock or modified engine. I have a mildly built 383 stroker wit an HEI distrbutor. Would I benifite by converting to an MSD?
Are you asking about a MSD box such as a 6AL? Your stock HEI is pretty good up to 6k ish. Once above that it can start to become a problem. Remember, it's one coil firing eight cylinders.