2002 Sonoma start problems

I have a 2002 Sonoma with a 4.3. It will not start unless I put fuel into the throttle body. After dumping fuel in it will run fine and run with no problems, when I shut it off and immediately try to start it again it will but if I let it sit for 30min to 1hr it will not start again. I thought it may be the TPS or the fuel pressure regulator but the error codes are EVAP canister vent blocked and two codes for both high and low tank pressure from the fuel tank pressure sensor. Would those emission problems keep it from starting?

The fuel pump was replaced about two years ago and works fine when running under load and express speeds so I figured it would not be the pump.

Might want to check gas cap or fuel filter. awhile back i had the same problem with my 95 sonoma and it was the gas cap.