Vanishing fuel
Thread Starter
Racer
Joined: Aug 2019
Posts: 253
Likes: 24
From: Oklahoma
Vanishing fuel
Has anyone had the experience of shutting off your car and almost immediately all the fuel drains out of the fuel line and out the return back to the tank. The car starts after a few cranks and runs fine but always smells like gas under the hood. It is a 1406 Edelbrock on my 5.7 sbc engine. Thanks if this happened and you resolved the issue.
Thread Starter
Racer
Joined: Aug 2019
Posts: 253
Likes: 24
From: Oklahoma
No regulator just stock mechanical fuel pump that does the same as the one I just replaced for the same reason. I don’t care that the line drains because it starts right up and runs okay but always a little rich and strong fuel smell. A lot has been said about boil off so maybe that’s why get the smell. I went with the Edelbrock foam Cap for hood clearance so I can put back on heavier filter and run regular gas instead of ethanol.
Drifting
Joined: Aug 2002
Posts: 1,775
Likes: 125
From: Birmingham AL
You might find more advice on the C2 and C3 forums. This section is mostly fuel injected. I’m thinking that the mechanical pump to carb line was never designed to hold pressure with the pump off?
Drifting
Joined: Mar 2018
Posts: 1,362
Likes: 400
From: DFW TX
How hot is the car running? I had similar issues with one of my previous hot rods. It was running 200-210F. When I got the cooling system under control and the engine ran at 165-185F, fuel would stay in the line and you could see it in the clear filter after shutdowns. Before it would disappear but there was plenty of fuel in the bowls to fire up and the filter would fill up in mere seconds. If you are running kind of hot the fuel might be vaporizing and that is why you get the intense fuel odor.
Other than that, it is kind of typical for fuel to drain out of the line with a mechanical pump. Some won't flow back some do. They tend to flow back more if you aren't running a return style regulator. If it is a deadhead setup, that pressure is going to bleed off somewhere as carb setups aren't truly meant to maintain pressure or keep fuel up top after shutdown.
Other than that, it is kind of typical for fuel to drain out of the line with a mechanical pump. Some won't flow back some do. They tend to flow back more if you aren't running a return style regulator. If it is a deadhead setup, that pressure is going to bleed off somewhere as carb setups aren't truly meant to maintain pressure or keep fuel up top after shutdown.
