Yet another MSD crank trigger wiring question

[Rob Petrie E395]

I think I posted about this problem several years ago. And you had told me about the water pump EMI back then. So I tried that by putting the water pump on its own switch. Didn't help. But it was worth a try. Thank you for the suggestion. I'm leaning towards a EMI problem. Just have not found it. Hoping when I rewire the car this time for the new HP system I find the problem.

Originally Posted by Adger Smith

Do you run an electric water pump?
I had a pump go bad(Leak) at a race. I had a spare in the trailer. No issue because I had time to change between rounds.
Next round I had a hi RPM stutter show up..
Changed the crank trigger pick up. Stutter is still there.
Sat there in the pits and thought the problem through.
Next round I kept the pump on during burn out and turned it off as I staged.
No miss that run.
When I got home I put a seal in the first pump and put it back on the car.
No miss next time I ran the car.
My conclusion is the pump was a radio station that produced RFI that interferes with the MSD. Probably the pickup since my V-6 uses a cam trigger and close to the pump.