Roadrunner w/440 Stalled

• Sep 7, 2025

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68roadrunner440

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Hey everyone. Could use some help here. Was driving my ‘68 roadrunner with a 440 BB and it just died. It will fire up when starting fine but immediately dies once the initial fuel is burnt in the 4bbl Holly 750. Does this over and over. Starts right up but dies after a second or so. I tried replacing the ballast resistor and no change. When pumping the pedal I see gas entering the throats so it’s getting fuel. Seems electrical to me. I say this because on a whim when starting after several attempts it fired up and stayed running but stalled again about 100 yards down the road: Maybe the point distributor but that’s only a few years old. Any advice would be extremely helpful.

 

• Sep 7, 2025

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Z-Man

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I had a cracked coil that would do that.

 

• Sep 7, 2025

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WileE

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68roadrunner440 said:

Hey everyone. Could use some help here. Was driving my ‘68 roadrunner with a 440 BB and it just died. It will fire up when starting fine but immediately dies once the initial fuel is burnt in the 4bbl Holly 750. Does this over and over. Starts right up but dies after a second or so. I tried replacing the ballast resistor and no change. When pumping the pedal I see gas entering the throats so it’s getting fuel. Seems electrical to me. I say this because on a whim when starting after several attempts it fired up and stayed running but stalled again about 100 yards down the road: Maybe the point distributor but that’s only a few years old. Any advice would be extremely helpful.

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This symptom, assuming you're accurate, indicates fuel starvation. Your description in bold points to the fuel bowl not getting replenished, which would be the fuel system from the tank to the float valve. Then you say it's getting fuel. Either it is, or it isn't.

 

• Sep 8, 2025

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Geoff 2

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Check the points gap. It has probably closed up. The rubbing block wears & the gap reduces to zero. On the way to that scenario, you were slowly losing HP & economy because the ign timing was retarding. One of many good reasons to go to elec ign....

 

• Sep 8, 2025

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59pwrwgn

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Try removing the condenser wire from the coil. And see if it is bad.

 

• Sep 8, 2025

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Moparfiend

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Check your float height on your carb.

 

• Sep 13, 2025

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68roadrunner440

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I spent some time replacing the ballast resistor because it seemed as soon as I let off the key, it would die. Replaced resistor and no coconuts. Then disconnected and reconnected the firewall harness plug connectors and it fired right up. Attempted several times and success! As I originally thought it to be electrical I think it’s this plug connectors on the firewall. Original ‘68 plug but wiring in car is all new. I’m narrowing it down. I thank everyone for their input! Big help.