Help Vapor lock

[Rschirka]

As previously mentioned, the vapor‑lock issues I ran into in Colorado with my AMC 304 V8 were caused by the fuel boiling right at the mechanical pump. There were plenty of contributing factors, and the problem only showed up on steep climbs in low 4WD. At the time I was running an undersized radiator, a flex fan (pulls less air at RPM than it does at idle by design) with no shroud, and I even had an exhaust leak under the hood, so the heat load was working against me from every angle.

Since then, I’ve made several upgrades. I switched to a Holley Sniper setup, rerouted the fuel line to the opposite frame rail away from the single exhaust, added an in‑tank electric fuel pump, and upgraded to an aluminum radiator with electric fans that I can override on if needed. I haven’t made it back to Colorado yet, but I’m definitely ready for the rematch !

 

[boney]

Late to the thread, but here goes.

Vapor lock is a combination of hot parts and poor fuel flow. Think of it like this: The fuel flowing through the system is also a coolant of sorts, as it takes heat from the parts it moves through and transports the heat to A) the carburetor or B) the fuel tank.

There are many ways to solve the problem as already mentioned. The easiest may be to check that your fuel return system is working correctly and if you still use the jeep metal fuel filter, that it is oriented correctly. This filter was designed specifically to eliminate vapor lock on a stock set up.