* Fuel System Location: The fuel lines and fuel tank were often located close to the engine compartment's heat source. This proximity meant that on hot days, or during periods of extended idling or stop-and-go traffic, the fuel could overheat and vaporize. Fuel vapor doesn't atomize properly, preventing it from combusting efficiently, leading to engine stalling or difficulty starting.
* Fuel Line Routing: Poorly routed fuel lines, particularly those exposed to excessive heat, exacerbated the problem. Heat would build up in the lines, further contributing to fuel vaporization.
* Fuel Pump Location: The placement of the fuel pump itself could also contribute; if it was positioned too close to the engine's heat source, it could overheat, impacting the pump's ability to deliver sufficient cool, liquid fuel.
* Low-Quality Fuel: Using lower-grade gasoline, with a lower octane rating and higher volatility, increases the risk of vapor lock. These fuels are more likely to vaporize at lower temperatures.
* Fuel Cap Issues: A poorly fitting or damaged gas cap allows fuel vapor to escape, which could also contribute to vapor lock in less direct ways by altering the tank pressure.
Ways to Fix Vapor Lock on a Ford Tempo (or similar vintage car):
Addressing vapor lock on an older car like a Tempo often requires a multi-pronged approach:
1. Improve Fuel Line Insulation: Wrapping the fuel lines with heat-resistant insulation (specifically designed for fuel lines) can help significantly reduce the heat transfer to the fuel, decreasing the likelihood of vaporization. This is often the most straightforward and cost-effective solution.
2. Relocate Fuel Lines (Difficult): If possible, rerouting the fuel lines to areas with better airflow and away from direct heat sources can be effective. This is a more involved solution and usually requires mechanical expertise.
3. Upgrade Fuel Pump (Potentially Necessary): An in-tank fuel pump that is more efficient, and better able to withstand heat might be necessary. An in-tank pump's location is generally better-suited than a pump mounted on the engine block. Consider upgrading to a higher-flow model if you have performance modifications or frequently use low-grade fuel.
4. Maintain Proper Fuel Cap: Always ensure that the fuel cap is properly sealed. A faulty gas cap can lead to a variety of issues, including vapor lock.
5. Use High-Octane Fuel: Opting for higher-octane gasoline (such as premium fuel) reduces the likelihood of vaporization because it has a higher boiling point. While more expensive, this can be a temporary mitigation strategy.
6. Check for Leaks: Fuel leaks can also lead to pressure changes in the system.
7. Shade the Engine Compartment: If possible, parking in the shade on hot days can help reduce engine compartment temperatures, indirectly reducing the risk of vapor lock.
Important Note: Working with fuel lines and the fuel system involves potential fire hazards. If you're not comfortable working on car fuel systems, it's best to take your Tempo to a qualified mechanic. Improper handling of fuel systems can be very dangerous.
