i have a 1997 s10 4.3 vin x. it has started misfiring badly, its a 5 speed and i barely have enough power to get off the clutch. i have 2 put it all the way to the floor for the rpms to rise, when i shift out of second into third gear i cant keep speed i drop speed and have to downshift. no power to go up hills. i need help. anyone know what could be the problem? p.s. the ses light has not came on, no codes at all. i have done a tune up on it and hasnt helped, changed fuel pump and hasnt helped. it shakes horribly and barely runs. any help will be greately appreciated thanks.