HEI Problem (Kind of Long)

[DT1]

So, I have a GM Delco HEI distributor and from the beginning the ignition module has been a real PIA. It goes out every two or so months. So often that I have to keep an extra one on board at all times. I figured that since it only quits when the engine is off, it must be getting too hot when the engine shuts down and all that heat from the block sinks into the distributor body. It has never failed when the engine is running. I just figured I could do nothing about it so for five years I've been driving around and changing them out when necessary. A few months back I was cruising on the freeway and the ignition momentarily shut down and of coarse when it re-lit, Kaboom. It got me home OK but I knew I had to figure out just why it did that. I checked the wire going to the distributor and changed out the module just for good measure and took it for a drive...Kaboom again! Grrrrrr!! I decided to take a look at the ignition switch so I pulled it out and disconnected the the connector...Hello. This is what I found.



I never smelled anything burning, so I figured it had been in that condition for quite a few years. I replaced the switch and spliced in a new connector, then took her out again...No more Kaboom. I felt so confident my ignition troubles were now in the past.
I've been driving around for quite e few months now with no problems at all...Until the other day. Now, every once in a while, I can feel a very slight momentary skip. At first I wouldn't allow my mind to accept the fact that the problem was back. I wanted to believe it was my imagination playing tricks on me. Sure, that's it. Not!
Anyway, now I'm at it again and and I would like to know where the most logical connection for the distributor power wire would be.
Right now I have mine (12Ga) connected from the distributor to the fuse block on the Ignition terminal (3C Pink). It's always made since to me. Could this be wrong?

[bigmac73]

i would make sure that the circuit is not the old resistor wire for the old points,
try hooking HEI to another hot Ignition wire/terminal

['68OrangeSunshine]

Do you have a stock External Voltage Regulator? I have heard of voltage spikes at high RPM killing the module, causing intermittant ignition.
I lately went back to points on my L6 292 in a '68 C/10, because a Pertronix Ignitor II would black-out at 65 MPH, causing your ''Ka-BOOM''. On points, its running great.

Another HEI issue is the grease between the module and the distributor base plate is a special heat sink formula, if you use the wrong stuff - like a dielectric- you defeat the purpose and the module gets hot anyway.

[Chknlyps2]

Originally Posted by '68OrangeSunshine

Do you have a stock External Voltage Regulator? I have heard of voltage spikes at high RPM killing the module, causing intermittant ignition.
I lately went back to points on my L6 292 in a '68 C/10, because a Pertronix Ignitor II would black-out at 65 MPH, causing your ''Ka-BOOM''. On points, its running great.

Another HEI issue is the grease between the module and the distributor base plate is a special heat sink formula, if you use the wrong stuff - like a dielectric- you defeat the purpose and the module gets hot anyway.

Like 68OrangeSunshine said, are you using the heat sink paste when you install the new module?

[Mr Handy]

Make sure you have a true 12v to the dizzy. I ran a new wire from an unused ignition terminal on the fuse block. Also make sure all your grounds are good and in tact. I was having trouble with modules and found I basically had no ground straps in my truck. It's amazing I had lights.