Hi,

My car is 4g15 carb sohc and just for the purposes of maintenance i decided to dismantle my mech fuel pump and check on the lever actuation against the pipes.

I noticed that the fuel in the return line was "pressurized". odd because (1) its a return line to the tank, and (2) i am running a carb with mech fuel pump, and (3) the engine was not runing for more than a week already.

paghatak ko ng return line, e biglag bumulwak ng dirediretso ang gasolina... malakas ang agos. so i returned it back to the fuel pump. on the other hand, the other 2 lines, suction and out line do not spurt any fuel... return line lang.

so i decided to open my gas tank cap. to my surprise ang lakas ng swoosh sound. i just don't know if its pulling air or pushing air out of the tank.

after doing this, when i pulled out the fuel return line, no fuel spurting anymore.

is this normal? because i don't think it is. what can i do about this? i have these options to look at, but can you guys help me shortlist these things to look at:
- gas tank cap needs replacement?
- blockage in fuel lines (i doubt, but worth looking at)?
- dirty fuel tank? (i also doubt)
- evap system? (isn't it that the charcoal canister is zero maintenance?)

one more thing, it seems that my mech fuel pump isn't able to suck in fuel on extremely hot weather...

???