Sick slant six stalling while driving

[holmike]

Hi All. I am looking for some ideas on my 71 Duster. It will start and run great idling, drives well and after about 10 minutes going down the road it will start losing power and will stall out while moving. Usually happens in second or third gear. It usually starts right back up. Sometimes I can restart while coasting and it will run a 1/2 mile or so and same thing happens again. I replaced the carburetor, thinking possible float issue but have the same problem. Also replaced the distributor cap and rotor to no help. I’m running a Holley 600 cfm carb, torque flight 727 manual valve body tranny on my 225. It also was converted to electronic ignition. I’m thinking fuel starving situation, possibly fuel pump but not really sure. Car was restored about 15 years ago and has never had any issues like this before. Thanks

 

[73 dart custom]

Hmmmm no idea... maybe if it is consistent with the 10 minutes time... could it be picking up something in the tank to clog the pickup... and then when it dies it drops it and starts again?

 

[jas0162]

Try a different coil.

 

[artr8]

someone already recommended checking the coil, so other things:

From experience on a 72 Duster, sounds like your condenser is failing. Will it start up just fine? After 5-10 minutes start losing power? Just barely idles and won't hardly pull itself? Let it sit for a little while and fires back up and does the same thing again? That would be on a points car.

Similar on a poor ground with an electronic ignition. Car runs well then runs poorly and stalls out. May or not restart. Ignition ground may be an issue.

Pickup on an electronic distributor; don't know why they go bad but may fail due to temperature. Doesn't necessarily run roughly, just quits like you shut off ignition. May or not restart. Pickup on distributor.

Last recommendation would be a dirty pickup in the tank. Starts pulling up debris from the bottom of the tank, clogs in the inlet. Motor stall or shutting of the car allows the debris to fall away. Start it back up and goes through the same cycle. Consider a fuel system cleaning from tank, pickup, lines, and filter.

 

[jas0162]

Uh... who mentioned the coil before I did? I had a truck do the exact same thing he is describing. It was the coil

 

[RustyRatRod]

Can you post pictures of the engine compartment? Particularly where fuel lines are routed from the pump to the carburetor?

 

[holmike]

You fellas were right, it was the coil. For some reason it was running to hot and burning up rotors. Replaced the coil and put on another distributor cap and rotor. It seems to be back in business and heading to cruises again. Thanks for the help!