Tank building pressure and blowing fuel out vent line...
11-02-2014, 05:11 PM
#1
Tank building pressure and blowing fuel out vent line... I have a 78 Cherokee with plans to re-power with an LSx, I began one of the first tasks and installed a 1997 Blazer fuel tank and fuel pump assembly with a regulator set to 2.5 psi with a return, all new parts.
I ran new hard lines front to rear, 5/16 vent and return and 3/8 for the supply, I connected the hard lines to the fuel pump with nylon fuel line and factory connectors.
I was test driving it today around the neighborhood and twice, fuel started blowing out of the vent line. This is odd because I only put 5 gallons in the tank and as I recall the, the vent line has a ball type stopper to prevent fuel from entering the vent when the tank is full, and, the return line dumps fuel back in the tank from the top of the sender.
How in the heck would fuel get into the vent opening at the top of the sending unit?
Edit: this is the pump, the supply connects to the hose and picks up fuel from below. The vent is the center outlet with the check ball and the return is the opposite side of the supply. Like I said, I don't understand how fuel could enter the vent line when I only have 5 gallons of fuel in the tank.
I ran new hard lines front to rear, 5/16 vent and return and 3/8 for the supply, I connected the hard lines to the fuel pump with nylon fuel line and factory connectors.
I was test driving it today around the neighborhood and twice, fuel started blowing out of the vent line. This is odd because I only put 5 gallons in the tank and as I recall the, the vent line has a ball type stopper to prevent fuel from entering the vent when the tank is full, and, the return line dumps fuel back in the tank from the top of the sender.
How in the heck would fuel get into the vent opening at the top of the sending unit?
Edit: this is the pump, the supply connects to the hose and picks up fuel from below. The vent is the center outlet with the check ball and the return is the opposite side of the supply. Like I said, I don't understand how fuel could enter the vent line when I only have 5 gallons of fuel in the tank.
Last edited by 243; 11-02-2014 at 05:40 PM.
11-05-2014, 06:46 PM
#4
No sir, the vent is not connected to the charcoal canister at this point.
It is possible the vent and return are swapped and I will check that when the rain blows through.
The puzzling part is how fuel would get into the vent or return line when both ports are at the very top of the assembly and there is not much fuel in the tank.
It is possible the vent and return are swapped and I will check that when the rain blows through.
The puzzling part is how fuel would get into the vent or return line when both ports are at the very top of the assembly and there is not much fuel in the tank.