I dont know whats wrong with it but when i first take off it starts vibrating feels like the truck is shaking it just started tonight when i was going home and right before it started it sounded like something fell off the truck it doesent even sound the same when it does it and when it gets up to higher rpms it seems to quit anyone have any idea's?

 

Did you check the connections to your intake and vac lines?

 

Not yet its dark havent looked at it yet