I am looking for help with my 66 Dodge Coronet. I have been trying to figure out and trying many things to figure out why my engine stalls. It only happens after driving for a while and it is the same each time where it just starts to run really rough like only a couple cylinders are firing or thats what it feel like and then it just dies. I can keep the rough running going for only like 10-15 seconds by playing with the gas pedal. I have looked into vapor lock and dirty gas. I have a new gas tank, sending unit, fuel lines, filter, fuel pump(original style) and i have a heat spacer under the carburetor. Gas lines are not in harms way of getting hot. Today i let the car sit for about half an hour and i was able to restart the engine. A while back i couldn't get it to restart so i had it towed home. Is it possible that this is something with my ignition coil? Or maybe my engine just gets too hot? The radiator cap read 210 when i checked it. I really appreciate some opinions from those who have experience with this sort of situation. I miss being able to take my car for long drives without worrying.

 

Welcome. I have had weak coils fail when hot. I would first check the bulkhead connector (firewall wiring) it is known to have bad or burnt wire connection points. When cold you could have a complete connection but as it runs and creates resistance and heat you will get a voltage drop.

If you can test voltage to coil + when running well then do the same when it runs rough you could get your answer and at least eliminate that as a problem.

 

Thanks for your reply. I read that about the coils elsewhere and perhaps it is the issue. I have a new wiring harness and bulk head connector so I would think that is fine. So do you believe the coil could cause a rough ride? I assumed that it would either work good or not at all.

 

j -

Unfortunately, it could be almost anything.

Besides swapping out stuff, what diagnostics did you do?

Pretty simple, when the engine dies, does gas squirt out when you operate the throttle? That should point you to a fuel vs electrical problem.

If the above points to fuel, did you check the carb: needle/seats, floats etc.

If the above points to electrical, then yes, coil, condenser etc...

Archer

 

If you have a points distributer try replacing the condenser......

 

Yeah. I'm thinking it may be something with the distributor. With closer inspection I found that the contacts don't seem to be lined up that great. I wonder if they eventually don't make good enough contact that the car ends up stalling....

 

j -

Replace the cap, rotor, condenser, points, etc. Probably due anyway.

Archer

 

I've had the condenser in a new Mallory dual piont go bad after three months, it would behave the same way. Get hot at STOP.

The replacement lasted ten years until I replaced the distributer with an MSD.

 

Make sure that you have an insulator gasket on the carb - keeps the fuel cooler and is what is probably causing the fuel to boil over