Fuel Pressure Problem

[Oldschool]

I am running a 434 SBC,700 HP,1050 Dominator on gas,A2000 Aeromotive fuel log with rear regulator with return line, A1000 Aeromotive fuel pump, plumbed per Aeromotive.
Went to the track testing and started engine to check everything. Just before burn out area started to die and could tell it was fuel starvation. Towed back to pit and started again and looked ok ,then notice regulator gauge reading zero and engine not running right.
Then got home took carburetor apart and checked. Took up to my shop a couple days later and started engine and running good and showing on regulator gauge 61/2-7psi. Got in car ,put in gear and did some take off several times and very strong with no problem. Got out of car with engine running and gauge shows zero ,but still running ok.I went through the lines and all checked out,what am I missing ? Ran this combination in a Vega door car and ran 9.28 in 1/4 mile. I took engine out and put in dragster.

[Totally T]

First thing I would look at is the bypass on the pump. I have used them several times including on my FED with no issues but they can fail like anything else.

I do find it curious that you are returning fuel from the carb, I have always deadheaded mine and ran two lines to the carb and ran a return from the pump back to the tank.

[Curly1]

I would not run anything that does not have a return regulator. First thing I would do is check and make sure pump is pumping. Pull the fuel line and make sure it is moving fuel. Then go from there.  If it is not moving fuel check to make sure pump is working, check grounds and make sure it is not locked up. Then check electrical and grounds.
If it is moving fuel then check regulator to make sure it is not stuck open some how.

[Totally T]

That pump has a return regulator....its mounted on the pump. He in essence is using two regulators and returning fuel with both.

[Oldschool]

Picture of set up

[BK]

It sounds like the only thing that really changed was the tank. I would look there. Is there foam in the tank? If the returned fuel doesn't get to bottom of tank through the foam fast enough it could starve the pump. Is the tank vented properly? Is the inlet to pump restricted?

[Oldschool]

I got on the phone with Aeromotive and told him what I had.He ask me what pre-filter are you running ,I told him Earl and he replied that is your problem.I went a little cheap instead of spending $120 for their filter I went with this for $40.He said the pump was creating a vacuum and boiling the fuel,causing the problem.I ran this system before with no problem but change to different filter,because of
space.I am just running gas this year then going Enderle Injection.
Thanks for your reply's and will let you know how it works out.