Grand Wagoneer Replacement Igniton Systems (CDI vs HEI)
'88 Grand Wagoneer
A few years ago my stock ignition system crapped out. I used it as an opportunity to "upgrade" my system. Replacement dizzy, the newer design large cap/rotor (Team Rush), a used MSD 6A, and a used Blaster 3 coil.
After 2-3 years, I started having issues. Initially thought it was vapor lock, then thought it was vaporization. Basically, would run fine for a period of 30-60 minutes (the harder I drove the shorter it would run) then would start to fall on it's face. After changing to an electric fuel pump, rebuilding the carburetor, adding an additional spacer, and verifying the issue was not fuel related, I took the rig to a shop. The shop said they believed the issue was in the ignition system but that they couldn't "load test" an MSD...only stock induction systems.
I called MSD. They advised me to replace the coil. Couldn't find a parts store that had one in so I ordered one. Two days later, that didn't work. Now, MSD is telling me that I could ship them the module and they would test it. All would take about 2-weeks. That would be fine; but, this is my daily driver...
I put the MSD system on because I was under the impression it was durable, more efficient, and "better" than an HEI system. That HEI had issues that made them less durable and not as efficient.
What I have noticed so far is that the MSD equipment is not stocked by anybody. I would hate to think about what would happen if this occurred when I was traveling out of town in the rig...
Guess my overall question is:
Is the MSD system really worth the risk of how hard finding replacement parts and / or shops that can diagnose are?
Is the HEI system really such an inefficient system?