help please

so i took my truck out for a drive afer sitting in the garage for about an 8 month long sit and a 14 month sit at the paint shop and only DRIVEN once. and when i stomped on the gas it sounded like a freakin lawnmower taking off in a race, and it seams to only do it when going up in rpm's when at idle it occasionally does it but mostly only when i accelerate or rev the rpm's up, once the rpm's level out it acts normal, till i step on the gas. so i thought it was maybe a fuel problem. i replaced the fuel filter, changed the oil, oil filter,air filter, checked the plugs and they all seem evenly worn but in good shape, i replaced the cap and rotor. only thing i haven't replaced is fuel pump, spark plugs or spark plug wires. now my truck has been sitting for a very long time with very few if any starts in between, so i put some fuel injector cleaner in and refilled the tank now i am at a complete loss as to what the problem could be. if anyone has any ideas please enlighten me. i'm very close to taking it into a shop and i don't want to do that cause people around here don't respect other peoples shit.

vaccum leak would be my guess what motor do you have?

are you getting any liquid comming out of your exhaust?

bad fuel injector thingie.....theres two of them in what looks like a throttle body thing. like electro injection. i had one go bad once....did the same shit.

SAME BS HAPPEN 2 ME WITH MY NISSAN I HAD 2 BUY A NEW FUEL PUMP, MINE SAT 4 3 YEARS. GOOD LUCK

I would finish the tune up with the plugs and wires and go from there.