Drive about4 to 6 miles the car starts to sputter and spit in fourth gear?

OLDDAD

MEMBER
1974 VOLKSWAGEN BEETLE
4 CYL
RWD
MANUAL
75,000 MILES

When I start the car it runs and idles great once I drive about4 to 6 miles the car starts to sputter and spit in fourth gear I shift down and have petal to the floor only runs at 50 mph for maybe a mile the car shuts off and won't start acts like its out of gas. Once it set for 20/30 mins it fires up and the process starts all over again. Replaced plugs distributor cap button wires and coil. Also traced the wire to coil no shorts found. Ne idea what might cause coil to heat up to cause car to not run

1 Reply

HMAC300

MECHANIC
48,601 POSTS

It should have 9 volts when running to coil only 12 volts on start. You may be missing a ballast resistor. There should also be 3 wires going to positive of coil. The symptoms you're describing in your 1974 Volkswagen Beetle could be caused by a variety of issues. While I can't provide a definitive diagnosis without physically inspecting the vehicle, I can suggest some possibilities based on the symptoms you've described:

Fuel Delivery Issues: The symptoms you've described, especially the sputtering, loss of power, and stalling after a certain distance, could be indicative of fuel delivery problems. This could be caused by a clogged fuel filter, a failing fuel pump, or a problem with the carburetor if your Beetle is equipped with one.

Vapor Lock: Older vehicles, especially those with carburetors, can experience vapor lock in hot conditions. Vapor lock occurs when the fuel in the lines vaporizes due to high temperatures, leading to fuel starvation and stalling. Allowing the vehicle to sit for some time might allow the vaporized fuel to cool and re-condense, allowing the car to start again.

Ignition System Issues: While you've mentioned replacing components like the plugs, distributor cap, rotor button, wires, and coil, there could still be issues with the ignition system. Make sure the timing is correctly set and that there are no loose connections.

Overheating Coil: You've mentioned that the coil heats up. While some heat is normal, excessive heat could indicate a problem. It could be due to an issue with the coil itself or an electrical problem in the circuit.

Electrical Issues: Since the vehicle shuts off and won't start immediately, there could be electrical components overheating or failing when the car is driven for a certain distance. It could be related to the ignition system, fuel system, or other electrical connections.

Heat-Related Component Failure: Some components might function normally when cold but fail once they heat up. This could be related to wiring, sensors, or other components affected by temperature.

Vacuum Leaks: Vacuum leaks in the intake system could cause performance issues, especially at higher speeds.