I have a '64 F250 with a 70something FE 360, 4x4, np4350. I'm not getting spark in 2 plug wires at idle. Oddly, it sounds fine at idle. When I give it throttle I get spark in the 2 wires but it doesn't seem smooth and continuous, it seems erratic and weak which I suppose is why under load it's sputtering and popping. I have a new dist. Cap and new plugs and wires and new coil, truck ran great for a couple months now this. I had put a new coil in a few months prior to this one and it went bad. Both were napa coils. I'm planning on modifying the ignition system with MSD coil and distributer. Any input from you guys would be helpful; I don't want to replace all of this and have a reoccurring issue.

Also if any of you are familiar with ford's XPI "extra power ignition" box I'd love some input. If I use a blaster II coil do I still need the box? Could that be causing any of my issues?
Thanks for all your insight in advance!

 

If you're idling on 6 cylinders, you should feel it. You probably really do have spark.

Load-dependent sputtering sounds like a carburetor, timing, or vacuum issue. I think you're wasting your time with the ignition system and the behavior you think you're seeing at idle is a red herring.

What does "went bad" mean? You're measuring winding resistance with a multimeter and comparing it to a spec? That's the only way you can say it's "bad."

You money is better spent elsewhere. Performance ignition carries quite a bit of marketing hype. A lot of people are going to tell you "it runs so much better" but they're not going to tell you in ways you can measure.

Never heard of it, and nothing came up in a Google search.

 

 

 

My mistake it is aftermarket. It's from hunt manufacturing.