I wrote before on this topic and thought I solved the problem. Here is my engine setup:
I have a rebuilt Chevy 350. It has a slightly higher performance cam. I have a Edelbrock 1406 carb (electric choke) with a mechanical Holey fuel pump.
Symptoms:
I start the engine and it runs GREAT. The fuel pressure starts at about 8.5 PSI. The fuel pressure gauge is between the fuel pump and carb. After the choke completes its warmup cycle, the engine drops in rpms as expected. However, after a while, the fuel pressure starts to drop from 8 to 7 to 6 to 5. Once it gets to around 5, it sunddenly drops down to 2 and the engine dies. I replaced the fuel pump and it still does the same thing. I removed the gas filter and it does the same thing.
I don't know if the problem is heat or the carb. I don't see how the output pressure of the fuel pump can be affected by the carb. There is no fule by-pass in the carb and I don't believe the fuel pump has a pressure regulator that reacts to carb demand.
Can the fuel pump rod freeze? I removed the fuel pump and the fuel pump push rod seems to move freely.
Any suggestions? I am bewildered here.
