Should fuel pressure remain when car is shut down?

[Myasylum]

Still having some issues with my car dying at stop signs, and hard starts. I have to pump the gas pedal down twice and hold it to the floor to start. A friend noticed after I shut the car down fuel pressure drops to zero. He said his car stays at 4psi running or not. I looked at it today and noticed the fuel filter no longer has gas in it either, so it must be siphoning back to the gas tank. I have a clear filter that is located next to the side of the alternator. Should the gas line be holding pressure? Is this what is causing hard starts? I have a new Carter Fuel Pump - M6903, and a AVS2 800CFM carb on a 400ci engine with a smallish cam.

Thanks!

 

[69L48Z27]

You have a lot going on. If you have a mechanical pump it should run at 7psi. Once the engine stops it will have some residual pressure for a short time. Fuel pressure by itself isn’t needed to start the car, not like fuel injection. The pressure will come back as soon as the engine starts running. Holding the accelerator wide open to start the car is a problem. Sounds like you’re flooding it or the choke is way off.

 

[twecomm]

If your car is a big block, you might want to check fuel pump push rod length.

 

[Myasylum]

It is a Big Block, the push rod is still the stock one.

 

[Dragon Slayer]

The filter should not go dry, so not sure why that is happening. The fuel pump has check valve so the pressure loss should be gradual, not sure why the tank would pull the fuel back into it, is it vented?

 

[Myasylum]

I have no idea about the fuel tank. It seems to have one line going to the fuel pump and three more on the gas tank just open. I bought it this way.

I'd have to look again to be sure.

 

[1967coronet]

New carb out if the box still in most cases will need the floats set. Also the air/ fuel screws adjusted.
When you seat one it should cause a change in the idle if it does not there is crap in it or a vacuum leak.
Eddy / Carter carbs should be ran around 5 to 6 lbs of fuel pressure.
Be real careful with those see through filters they are know to start a fire. Lack of fuel in the filter or lines could be from heat soak after shut down.
Today's fuel evaporates and boils faster than the fuel from a few years back.

 

[moparedtn]

Yep, many of us deal with having to bring fresh gas up from the tank after the car has sat a couple days....
The fuel in the bowls, etc. just disappears, thanks to crap quality anymore.

 

[Dan64]

Those clear plastic gas filters start more car fires than ex wives.