Should the gas tank become pressurized?
I’m looking for your thoughts regarding my issue.
I installed a FiTech Fuel Injection 31003 Go Street 400HP kit (external FiTech in line fuel pump) on my Chev 350 crate engine back in 2020. In the last couple of years, the gas tank has started to experience a pressure build up when operating the car. I’ve confirmed the fuel cap (vented unit from TANKS) is functional. Why would there be a pressure build up in the tank? This now happens all the time regardless of the ambient temperature. I’m assuming that since the fuel pump is extracting gas from the tank and returning only fuel that is not consumed that there is a net loss of fuel in the tank so the internal pressure should be neutral or lower.
I’m running the T210 GoEFI 30003 20210824 software. The fuel pump initial set up is Pump PWM Low Fuel 60.0 and the Dashboard shows Fuel PW 4.80 ms while engine is running.
It has to be the gas cap. Drive the car a bit w/the cap removed to confirm then replace or repair the cap.
I can certainly run a test with the gas cap off but what would that prove? Any pressure build up would be released out the open filler pipe.
The bigger question is - does the FiTech system produce a positive pressure in the gas tank under normal operation? If so, why? And if this is not normal behaviour, then do I have a set up or defective component in the FiTech system?