Ok, first off the car has been rewired to bypass the VAT system. Tank is getting proper voltage, pump is priming, new pump, new filter, cleaned lines.

Alright.. Now, when I turn the car to the on position the fuel pump primes and according to my PSI gauge attached to the weep hole on the injector line it goes from 0-21 PSI. Then leaks back down to 3 PSI within 3 seconds.. Can't get proper pressure. I noticed that when you prime the tank a sound like your letting air out of a tire when traced back it is coming from the tank. I checked the seal around the top of the tank and it is sealed properly.

So my question is: Is there anything that could be causing the tank to release the pressure on the tank after it hits a certain PSI or is there anything I should be looking for? And how much gas should be in the tank to properly test the PSI again?

 

Less than 5 gallons is enough fuel to make sure the pick up gets enough fuel. Sounds like you have a either a bad pump, bad check valve in the pump, or the line/pulsator between the pump and the sending unit is bad. Anothe possiblity since you have a strange noise while priming is line may be hooked up incorrectly.

 

Sounds like a bad fuel pump or regulator. 21psi is not enough you should be getting around 41 or so.