Hello folks, new member here. Iím a little stumped by my intermittent stalling and some no starts with my vehicle. I have a MSD 6425 Digital 6AL installed with a new Ford Duraspark 2 distributor on a 1973 Ford F-100 240 ci six. (Same engine as the Ford 300, 4.9L, etc.)

Iíll start from the beginning. I purchased a distributor and sent it out to have it recurved by a friend. He recurved it, everything checked out fine in his opinion. He also had a remanufactured 6AL as a spare, so I bought that from him. Installed everything as well as made a set of MSD spiral wound wires, and used a MSD Blaster 2 coil.

This setup ran fine for a few weeks. Took a six hour trip, commuted, everything. The truck started hesitating at times. I replaced the fuel filter thinking maybe I was having fuel stumbles. Then it started to break up going down the road, and stalling at stoplights. It would restart and keep going.

At this point I went through and cleaned everything. Cleaned the MSD ground on the block, added a ground wire from the block to the firewall, cleaned the connections on the MSD hot wire, and put a new clean connector on the Fordís old coil trigger wire. Still stumbling and stalling. Tried running a hot directly from the battery to the MSD trigger wire thinking that the truck might have an issue there. Still stumbling.

Eventually the truck died on the road and would not restart. I ran through the MSD troubleshooting in the instruction manual and did the test of shorting the input from the distributor to see if a spark could made at the coil. Nothing. Okay, at this point Iím guessing the 6AL is simply faulty (being remanufactured etc maybe itís just a lemon).

Ordered a new MSD #6425 from Summit and put it in. Started up and ran a while, then started to stumble again. I stopped at a parts store and tested everything with a meter to the MSD socket for the box. Still had good power and continuity on everything. Checked the coil and it had .7 ohms between the terminals and 5.7K Ohms between the terminals and the center output post. This seemed high to me, so I bought another Blaster 2 coil and installed it. I also took the cap off the distributor and cleaned up a little carbon dust on the rotor. Seems like dust from the coil peg on the cap? Took off each plug wire and had a guy hold the meter probes to each end while I flexed them around a bit wondering if I had a poor connection. All of those seemed fine. Truck started again and ran the rest of the day no problems. The next day it gave a few more blips of stalling.

Iím not really sure where to check next at this point. The MSD 6 unit has been replaced, the coil replaced, plug wires seem fine. Maybe bad cap or rotor? Bad ground from the battery to the engine block? I think I taped up the wire intended to be used with a points setup, maybe its shorting against something? Canít imagine the keyed trigger source is bad as I bypassed that straight to hot and still had a problem. Just kind of stumped at this point.