I have been running with a DUI hei distributor on my 390 for about 10 years and really am impressed with it...but it seems to have a problem with ignition modules lately. 2 in about a year or so...and the last one looks as if it may have been running hot. Does anyone have any insight that I can start looking into this problem with?

 

Moved to proper forum.

 

Make sure you are replacing the grease under the module when you put the new module in.

 

Both surfaces must be COMPLETELY clean and FLAT before the heat sink compound is applied and the module replaced. Use the white heat sink compound, not the clear stuff. You can buy a small tube from Radio Shack # 276-1372 for a couple bucks.

 

Do you apply the heat sink grease to the fender wall under the module?
Why, does that cut down on the heat to the module?

 

The older style duraspark module on the fenderwell is self contained, has it's own heatsink, and needs no grease.

The HEI module in the above threads is an individual component that has no heatsink itself. It's mounted inside the distributor which is used as the heatsink, so it needs the grease to transfer the heat from the component to the heatsink(distributor housing in this case).

Later model Ford TFI modules that mount on the side of the dist, also need the grease. They are just grey plastic with no heatsink, so the grease is needed to transfer the heat to the dist housing. Ford also remotely mounted the TFI module in certain models, on the fenderwell, on an aluminum heatsink. These also get the grease, since it is still a small plastic component with no heatsink built in. But the grease goes between the component and the heatsink. Nothing goes on the fenderwell.

 

The Duraspark modules should be mounted on 1/4" high standoffs to allow cooling air under the unit.