Need MSD HEI help
 

I bought a new MSD module with rev limiter for the HEI in my 69 c10. Installed it correctly and ground it to the negative battery terminal. Now the engine will barely run. It sounds like it is running on 1-2 cylinders and won't exceed ~100 rpm, then dies a few seconds later. I thought I had a defective module so I exchanged it for another one, same problem. I thought maybe my stock coil wasn't good, so I bought the overpriced MSD one recommended for the module. Same problem. Put the stock stuff back in, runs just fine. MSD tech was no real help so I figured I'd ask on here if anyone had any idea why I'm having this problem. Thanks for any input.

Re: Need MSD HEI help
 

This is from their website. I wonder if there is a conflict with the module and your ignition system.

TRACTION CONTROL DETECTION
The Extreme Digital HEI Module has a unique Traction Control Detection (TCD) code built into
its microprocessor. This technology carefully monitors and examines the signals of the ignition.
If the TCD determines that any signal has been modified in any way, the ignition will be put into
a low rpm rev limit mode to immediately slow the car. Before this rev limit is imposed, the TCD
goes through a list of cycles and checks to qualify that the trigger has been modified. There is no
way to bypass or deactivate the TCD circuitry.

Re: Need MSD HEI help
 

That sounds like it could be it, I'll have to check into it.

Re: Need MSD HEI help
 

Make sure your running a FULL 12 volts to the Dist. If you have replaced a points type and are using the wire that went to the coil you have a ballast resistor in line and are not getting the voltage you need. Make sure you run a good sized wire to the dist from the fuse block. Find you a keyed on source.

Re: Need MSD HEI help
 

Running a new wire from the "ignition unfused" spot in the fuse box to the power terminal on the distributor did the trick! Thanks for the help!