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Summit - MSD box

Summit - MSD box

Basod

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Mt. Cheaha, AL
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'84 CJ7, 258, T4, D300, D30, AMC20, 3.54 gears
I've about had enough of the Ford Duraspark modules.
Since doing the Teamrush upgrade and eliminating the ballast wire I've blown 2 coils and three modules. The last one conked out in the middle of the national forest - fortunately a passing Deputy gave me a lift back to my house.
I've put the ballast wire back in and the coil seems to be staying cool with my original old ICM reinstalled - getting pretty proficient at swapping those now.

I'm looking at the Summit manufactured MSD box - from what I gather its made at the mSD factory in TX.
 
10(ish) years ago I bought a Summit Racing Brand ignition box because it was $AMC 150 cheaper than the MSD equivalent, same thing, made by someone else just rebranded as Summit Racing, well about 4 years ago when it quit working Summit didn't carry them anymore, and then "tech help" folks were no help because there wasn't any documentation on them. Ended up buying an MSD box to replace it.

Moral of my story, if I'd have bought an MSD box to start with, when it went bad I could have sent it back to MSD and either repaired or replaced, instead I paid full price for 2 and ended up with an MSD box anyway.

I have a 6AL with a Blaster SS coil and I have no ignition issues.
 
Go with MSD and the Blaster coil.
Gary
 
So I bought the MSD 6al and the dizzy adapter. Cut one of the loops for 6 cylinders.
Got no fire- it sounded like it coughed one time.
Checked for spark using a jumper on the pickup wires and I hear and see solid spark. It ran fine before I installed the box.

I did notice the dizzy adapter seems to change polarity and I did try adding a ground to the dizzy direct to battery.


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Last edited:
I just had the GF crank it and checked for spark to the #1 plug and it’s bright blue.

I have the NAPA Belden wires from the team rush upgrade- assuming these aren’t solid core?


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I just had the GF crank it and checked for spark to the #1 plug and it’s bright blue.

I have the NAPA Belden wires from the team rush upgrade- assuming these aren’t solid core?


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Now that you mention it, I’m not sure that the are

I went with MSD wires...got them at the same time I ordered the box

There are others, too...Accel, etc...bet that’s the issue, though
 
Now that you mention it, I’m not sure that the are

I went with MSD wires...got them at the same time I ordered the box

There are others, too...Accel, etc...bet that’s the issue, though

I did some googling on it. Appears solid core wires are not very common, mostly racing applications. The main reason to not use them is the amount of EMF they produce can interfere with the triggering circuit, or other electronic components.

I tried moving the dizzy a couple degrees either way while cranking last night with no luck. It was set at 8deg BTDC. I know the original durasparks provided timing retard on startup for easier starting.

Only other thing I didn't do was open up the plug gaps, which I'll do this afternoon, and double check the timing on crank.
 
I did some googling on it. Appears solid core wires are not very common, mostly racing applications. The main reason to not use them is the amount of EMF they produce can interfere with the triggering circuit, or other electronic components.

I tried moving the dizzy a couple degrees either way while cranking last night with no luck. It was set at 8deg BTDC. I know the original durasparks provided timing retard on startup for easier starting.

Only other thing I didn't do was open up the plug gaps, which I'll do this afternoon, and double check the timing on crank.

Might double check the coil connector

If I recall correctly that's one of the more common issues that pops up
 
...do you have power to the MSD box during cranking? It needs to be on a circuit that maintains power during and after cranking.

77 and older did this by default, 78 and newer you had do find something in the fuse panel that ran this way.
 
...do you have power to the MSD box during cranking? It needs to be on a circuit that maintains power during and after cranking.

77 and older did this by default, 78 and newer you had do find something in the fuse panel that ran this way.

I'll double check the voltage in crank, but its full 12V in run, flashing and producing spark
I know the original setup uses a jumper from starter solenoid to provide full 12V in crank and then the ballast wire Limited to 6V in run -I connected to the ignition harness where the ballast wire jumpers in to the harness near the firewall.

I'll try small red direct to the battery to eliminate any issue there.
I'm leaning towards either plug gaps, or the polarity of the dizzy coil - seemed odd the connector plug pn 8869 swapped the cable colors
 
My experience with the MSD ignition 6A didn’t go too well. My ignition wires and spark plugs were consumed prematurely, I guess due to the very high ignition energy. This was back when I had a GM 350. Ended up removing it and honestly, no difference in performance with stock GM HEI. I still have the unit somewhere in storage.
 
So tried the small red straight to the battery it barely sputtered and died. Gapped all the plugs to .054 and tested them 2&4 looked a little dark 1&6 look a touch lean. It still didn’t start.

Hooked the old ignition back up and fired instantly.

Started down the rabbit hole that I’ve read up on with rotor phasing and drilled a hole in my cap- it definitely appears to be firing #1 way before the rotor is near 1 cap plug.
Going to try to move the dizzy 1 more tooth advanced to see if it changes anything before moving the reluctor.


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...you may need to retard one tooth on the dizzy right?

OR - set crank to TDC and line up distributor ON #1 to give yourself a clean slate, then you can back it up a touch to give yourself that 8-10deg advance at crank.
 
...you may need to retard one tooth on the dizzy right?

OR - set crank to TDC and line up distributor ON #1 to give yourself a clean slate, then you can back it up a touch to give yourself that 8-10deg advance at crank.

The rotor is almost right on #1 at TDC. I think what I'm seeing is the reluctor is mid sweep with the rotor between #1-2
I may be confusing direction(retard/advance) - dizzy turns CW
I'm just barely seeing the left edge of the rotor through the 1/2" hole I drilled at #1 cap plug

So you're probably right I need to retard - move the rotor further CW.
If advance fires sooner(further CCW) then I'd be firing #2 in place of #1...
But then that seems like the entire distributor is retarded firing everything late.
 
If you’re just barely seeing the left edge of the rotor and it turns clockwise then the rotor has passed number one so we may have 10° retardation. Meaning you were correct that you need to advance the spark so that you’re just seeing the right edge come into play.

I always have to remind myself to think backwards. Advancing it means going backwards in rotation.

If you put #1 at TDC and line the distributor up ON #1 then you’ll know for sure where you are as a start. If we’re not talking about TDC on number one, then where the distributor is will never really matter.


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I think we were on the same page but what I was seeing was the left edge of the rotor sweeping into the hole- so maybe right edge if you were thinking of looking top down on the dizzy.

Moving it a tooth made no difference.
After looking closer when the rotor was lined up on #1 the reluctor was in an open gap way off from the pickup.

Pictures won’t load on tapatalk right now but I’ll try to do a write up on it.

Anyway I took the rotor off my old dizzy and swapped it in on my new one as the key slot was cut differently where the reluctor was directly on the pickup with rotor pointing to 1.

Reinstalled with original ignition fired right up and set time to 8* and the rotor was directed at #1 with my light.

So hooked up the MSD and it fired on half revolution just sounded hard like way advanced. Checked with my light and couldn’t see the timing mark, so slowly retarded until around 10*

The crazy thing is the rotor is back to where I see just the left edge with the MSD firing it.

Either way the old ignition with the rotor phased correctly cleaned up the idle no intermittent blub blub in the exhaust note.

Still need to install the diode as it is running on- charging wire is jumpered right there in the harness.


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I think we were on the same page but what I was seeing was the left edge of the rotor sweeping into the hole- so maybe right edge if you were thinking of looking top down on the dizzy.

I guess I don’t know where your hole is. When I think of a clockwise rotating rotor, I think the right edge of the rotor will enter the hole first followed by the left edge.

Regardless you’re improving and that’s what matters. Good work.


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Couple pics of the reman dizzy.
The rotor is pointing to #1 where the sharpie mark is and you can see the reluctor is past the trigger coil. The dizzy is essentially stuck with advance rotor not phased correctly.
5dfa8587a1fd21f32438681d1f33303f.webp

After I swapped the upper shaft the key slot was cut in a different location allowing the reluctor to line up center of the pickup with rotor directed at #1.
ebaf642e9c492a0caf727169e6878e2d.webp


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