I have a history with MSD since I have built several Chevy motors using their complete ignition systems. The MSD 6A box has left me stranded more than once and that last time I was in heavy traffic coming up to a stop light. I pushed the clutch in and the engine stopped. I had to get my Jeep towed back home and then I replaced the box. I went through three of the 6A boxes before I sold the Jeep. Now forward to the Scrambler. I have a Chevy 6 cylinder HEI distributor that I converted to fit the 258 motor and I installed an MSD high energy coil brand new. I used a factory ignition module and Autolite plugs with the correct gap. I also have a quality cap and rotor with copper leads. I even put alot of time into setting the mechanical and vacuum advance curves to be perfect. From day one I have had a slight missfire in the motor and I could not trace it down. Also when I would come off a a higher RPM the motor would almost stall before settling back to its normal idle. I always figure this was my carb creating the issue. Last summer I switched over to to a used Howell TBI kit and the motor ran better but still had the idle drop issue. I just learned to live with it since I usually do not get alot of free time during the day to mess with tuning it perfect and it runs "well enough". So a few weeks ago the miss got real nasty and I was affecting my acceleration and drive-ability. I went through the whole ignition again and as usual the plugs were reading perfect and everything is in great shape. I have an extra Airtech coil hanging around and decided to change it out to get the MSD out of the equation. This morning I drove the Jeep to work and walla, it runs perfect. Great drive ability, smooth idle, no drops or stumbles. I thought I would have learned from my errors but this time I am done. Sometimes the aftermarket is not the way to go. The crazy part is I prepping a multiport 4.0 setup to replace the Howell next month and I am using the 4.0 ignition. If this heavy stumble didn't get worse I never would have bothered to even find the problem.
Why I will never buy MSD again.
- Thread starter Kane
- Start date
Wow sorry to hear what you are going through. I have their Digital AL6 and a blaster coil that has been working great since I installed a few years ago. My CJ has never run smoother or better. I'm rebuilding a 4.2 to install eventually in my jeep and just spent a load of money this week in new MSD ( distributor & wires ) and Holley (Snipper )parts. Guess I'm goin to cross my fingers and hope I have good stuff. 
- City
- Cave Creek
- State
- AZ
For the Chevy V8s, they have dedicated relays for their aftermarket ignition coils. I've read a number of complaints of failing MSD coils in the V8s, which I think are correctable with the MSD-supplied relay for an additional $70.
I don't know enough about the 4.2 system to know whether a dedicated relay to the coil would be helpful or not. Been a while since I've worked on that system.
I don't know enough about the 4.2 system to know whether a dedicated relay to the coil would be helpful or not. Been a while since I've worked on that system.
I have a msd 6al in my 90 5.0 Mustang. The box died once on me. It was 15 years old, so no complaints. They would rebuild it for a decent price but I just bought a new one, could not wait for the turn around time. Only complaint is my engine will power through the 6,000 rpm "rev limiter" chip and hit the factory one at 6250.
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