[428RA4]

Hello all -

I have a bizarre issue with an after market MSD ignition distributor and a stock wiring harness. Apparently the module that is in said MSD distributor freaks out and jumps the timing 10 degrees at 2500 RIM's due to the 6 volt bypass wire that comes off the starter that runs up to the coil. Since I'm running a stock starter I 'm not sure where to start to fix this issue. Apparently when MSD developed their modules they assumed a 12 volt constant system which kind of sucks if you want to run an original wiring harness.

Anyone else experience this condition?

thanks
mike

[bryansMtngto]

i would think disconnecting the 6 volt bypass, and making sure the MSD has a constant 12 volts would solve your problem. You may have to add a wire or 2 to your stock harness.

[428RA4]

Yes, that is my assumption, but I was looking for a step by step process to go about fixing this issue.

[Ollie]

First of all the name Test and Turn refers to test posting photos, videos and other visual aids.
This should be posted in the Street or appropriate year Firebird Tech forum.
I assume this is on the 68 Firebird in your avatar.
Yes this is a well known condition when converting from points to HEI.
If you converted from a points distributor to a HEI, with out changing the resistance wire then yes you will have problems. who is going to look at a wire and not know it is not original. By the way, The wire that runs from the starter to the coil is 12 volts and the wire from the harness to the coil is the lesser voltage. The 12 volt wire from the starter is to provide a stronger spark at starting. the 12 volts are only hot when the ignition switch is in the start position.

The fix is to cut the resistance wire out of the harness and replace with non resistance wire.
another fix is to order a new engine harness and tell the manufacture the distributor is a HEI.