Question Fuel pressure issue

[GypsyR]

Highly unusual to see vapor lock on EFI engines. Note the link to the thread above is all about a person with a CARBURETED 460 and about nothing he did and experienced applies to a fuel injected 1989 model. The 4.9 engines had some issues as the injectors were placed unhappily close to the exhaust manifold. To combat those issues Ford had a fan that blew fresh air onto them and also ran higher fuel pressures. But again, a different engine and does not apply here.

 

[Kevin D Pem]

Highly unusual to see vapor lock on EFI engines. Note the link to the thread above is all about a person with a CARBURETED 460 and about nothing he did and experienced applies to a fuel injected 1989 model. The 4.9 engines had some issues as the injectors were placed unhappily close to the exhaust manifold. To combat those issues Ford had a fan that blew fresh air onto them and also ran higher fuel pressures. But again, a different engine and does not apply here.

Agreed! Here is a chart that puts that issue up front, and on the table! They cured vapor lock when they put the pump in the tank!!!

 

[Joe Hogan]

Guys, I agree that FI engines are less likely to suffer Vapor lock. It sure sounds heat related rather than random debris blocking fuel. Pressure regulator too hot?
When the engine will not start you might loosening a return line to see if fuel is flowing. Or better yet put in a pressure gauge inline to see the changes between running condition and not. Have an extinguisher nearby just in case.

 

[Kevin D Pem]

Temperature related, yes! Faulty pressure regulator! Maybe. Checking pump pressure, definitely.

I will stick with Temperature sensors. (Ambient, and engine). They regulate injector timing (fuel mixture). MAP sensor/air flow sensor??? That would show up on the O2 sensors.