Howdy! 1978 F-150 with 400M. Engine runs like a champ (when it's running!) Edlebrock carb and manifold, headers. Fresh rebuild with zero issues for about 13000miles/1 year. Everything is tight. Fuel is clean. No fuel delivery issues. Carb is properly adjusted, to include electric choke. Ignition switch NOT loose or any hanging wires.

PROBLEM: After warm-up while driving under normal conditions, engine will die for apparently no reason. All electrical items are still working (lights, radio, etc). Pull over, put in park, immediately starts right up and runs. Will continue to do it all the way home. Daughters daily driver so this is unacceptable.

Sat in the garage with engine idling after warmup, wiggled ignition switch to no effect. Disconnected duraspark, engine dies. Reconnect, immediate start-up.

Any assistance would be greatly appreciated.

 

This is a classic symptom of a dying DuraSpark module; take it (the DS2 module) to an
auto parts store to be tested.

 

Second on the DS module. Another possibility is a dying magnetic pickup in the distributor. Both exhibit the same symptoms.

 

Appreciate the info...I start with the DS2, and keep the magnetic pickup in mind also.

Greatly appreciate the help.
ks

 

Had the same problem on my 78 F150, just changed the control module and pickup coil 2 hours ago, Problem solved

 

I have the same problem with my '76 302 in my '84 Bronco were it dies randomly and in the most inconvenient places (turn lanes, middle of intersections, petrol stations, etc... picky girl she is. I swear when she does that sometimes shes laughing).
The Duraspark II ignition module is a gray box with 6 wires coming out of it yes?
Mainly does it when the engine is cold and warming up to operating temp but also does it when the engine is warm to. And also the ignition module gets really hot, almost to hot to touch sometimes, is that normal?