there is a big problem it still missfire after i change the pump it doesnt idle at all you step on the gas at 2500 rpm and still missfire and if you dont repress the gas manytimes it is still stall at 2500 rpm all i did is try to check the blower and put it back on is there any harness or wiring on the way that can cause that reason? pls help what are the other reason for it to missfire and after it stall i can hear a sound on the back like a ziziizizzipping sound on the right back

1) i checked the distributer and it looks fine
2) the fuel filter is also good
3) i tried checking the spark plug but dont know how to take it off i was trying to pull it but i dont think it goes that way
4) where is the fuel pump located at