[DeTomaso] MSD 6AL failure modes

[richard bosch]

I used to manage an auto parts store many many years ago.
We sold and warrantied many ignition boxes from all makes and brands.The most common to fail were the ignition modules mounted in the distributor.General Motors HEI, Ford TFI.External ignition boxes such as the Ford Duraspark and Chrysler would have around 10 percent of the failure rate of the distributor mounted ones despite there higher numbers on the road at the time.
Vibration and heat are the enemy of the ignition module!There are kits out now that relocate distributor modules to a heat sink that you can remote mount off the distributor like to a fender or firewall.
Mallory Unilite distributors by far had the highest failure rate of any of the aftermarket brands.
MSD boxes had a much lower fail rate than the other aftermarket brands.The most common reasons for failure were lack of vibration isolating mounts(the mounts are not included in the 6A box for some reason,but are available separately) and wiring mistakes.It is amazing how often wires are installed incorrectly!
When an ignition box fails it is usually instant and when it is warm from use.Several times customers would come in and say it would work only when the car was cold and would fail after 10 minutes too 30 minutes(especially Chrysler boxes for some reason).
For what it is worth i use MSD on everything i own that is modified and factory electronic ignition boxes on mild or stock engines.I have yet to have a failure of an MSD personally in over 26 years and several cars.A few Duraspark,Chrysler,Ford TFI(i hate this one!PS it takes a special wrench that all parts stores carry for this one) and GM modules have died on me.Of course these is just my experiences and each car/truck is different.
PS,Bob Benson has a msd HVC race coil that is not recommended for the street and he literally destroys the center contact post on the cap