bad fuel pump or no gas
The fuel filters in the gas pump need changing.
it is useless to pump the gas in a fuel injected truck the pedal only controls the intake of air not the gas
clogged intake line or restricted vent tube.
ethier way it does not matter.
running low gas
The fuel pump is engaged.
The fuel pump diaphragm has broken. Needs new fuel pump.
it might men that your gas intake lever is sticky or rusted
Probably a bad fuel pump.
A gas engine does not have a vacuum pump. Vacuum pumps are used on diesels only as they do not pull vacuum from the manifold. Gas engines use vacuum lines (usually stemming from intake or throttle body)
Throttle body injections (TBI) have what is callled a wet intake where the fuel is sprayed into the intake instead of the intake runners with port fuel injection. The fuel vaporizes and can make the air cleaner smell like gas.