hi i have a 94 mighty max that i busted the gas tank on,so installed one from a junk truck not getting it cleaned out well so it got rust in the fuel and lines so i got old tank fixed changed it back out the changed fuel pump sock,have changed two fuel filters and ive changed the Plugs,Plug wires,Dist cap,Button, everything and when i crank it has a shake and sputter and when i give it gas it skips,sputters and does some backfiring but if i hold the gas down it will eventually clear up like nothing is wrong and take off till i change gears and it does the same thing again oh and i took the fuel line off the fuel rail the fuel looks clean and clear coming in, any ideas please help this is frustrating?