I changed my fuel pump and with the new pump i'm reading 30 psi at the pressure test point. I know i should get between 41 and 47 psi at run.....

My buddy thinks that my gas tank isn't getting pressurized.....i found a vacuum/pressure line broke in front & top of the engine area......the hose (hard plastic type) went to the fuel line bundle in which the other 2 fuel lines goes to the fuel regulator.....i take it this is the line that should pressurize my fuel tank???? However, after fixing it, i started the engine, same weak fuel pressure, and i pulled the hose off and there was no vacuum or blowing of air at all. I followed the line and it goes to the passenger side of the fuel rail to a little box, in which 2 lines go to. The other line is a vacuum line that connects to the side of the front of the air intake. Could this little box be bad??? Is this what pressurizes my tank???

I even disconnected the 2 lines going into my gas tank (the 2 that aren't my feed or return lines) and there is no Blow, or any signs of vacuuming or whatever.....

Anything will be helpful! Thanks!

 

Your tank is not pressurized as such, just the fuel in the fuel line. The plastic hose that goes to the "little box" is for the EVAP canister purge. It draws fumes from the tank to burn in the engine, but is not engaged at idle.

You should have 41-47 psi at idle with the vacuum hose removed from the regulator. Pressure might be in the mid 30s at idle with the vacuum hose on.

 

Thanks, that makes sense now.

With my old fuel pump, i was getting 20 psi at Run & Idle. My new one shows like a "quick" flicker of pressure and then reads 0 in Run, but it reads 30 at Idle. It does take a few seconds to crank it over.

I just don't know how it even starts when reading 0 in Run??? I just don't want to have to replace the Fuel Regulator if i don't have to, but i guess it's the next step. It could be my new fuel pump too though.