1. Vapor Lock: This occurs when the fuel in the carburetor turns to vapor due to excessive heat. When the engine is turned off, the fuel pump stops delivering fuel, and the residual fuel in the carburetor begins to vaporize. As the vapor pressure increases, it can cause fuel loss from the carburetor. To mitigate vapor lock, ensure proper fuel line placement, adequate ventilation around the carburetor, and use a heat-resistant fuel line spacer or insulator.
2. Fuel System Leaks: Inspect the fuel lines, carburetor gaskets, and fuel pump for any leaks. Loose or damaged components can allow air to enter the fuel system or fuel to escape. Check for any signs of leakage, and replace or tighten any faulty parts as necessary.
3. Stuck Float or Float Valve: The float and float valve regulate fuel flow into the carburetor bowl. If the float is stuck or the float valve is not closing properly, it can lead to flooding and eventual fuel loss. Make sure the float is moving freely and the float valve is properly seated and functional.
4. Accelerator Pump Diaphragm: The accelerator pump helps to supply additional fuel when the throttle is opened suddenly. If the accelerator pump diaphragm is torn or damaged, it can cause fuel to drain back into the fuel bowl, resulting in poor fuel prime. Check the accelerator pump diaphragm for any defects and replace it if necessary.
5. Incorrect Fuel Pressure: The carburetor operates within a specific fuel pressure range. If the fuel pressure is too high or too low, it can disrupt the proper operation of the carburetor. Ensure that the fuel pressure is within the recommended specifications for the Chevy 350 carburetor.
6. Clogged Fuel Filter: A clogged fuel filter can restrict fuel flow to the carburetor, leading to fuel starvation. Regularly inspect and replace the fuel filter to prevent fuel restrictions.
7. Check Valves: Some carburetors have check valves to prevent fuel from draining back into the tank. If the check valves are faulty, fuel may leak from the carburetor after the engine is turned off. Ensure the check valves are operational and replace them if necessary.
