Ok, My 81 Dually is struggling with performance issues. 52000 mile orig. parked for 6 years. I pulled it out, cleaned the fuel tank, replaced all the fuel lines, new filter, new plugs,cap ,wires, rotor button. Some trips it pulls strong no issues, next time I drive it it falls flat on its face mid throttle. I either have to downshift or floor it or both, then it will pull through. Some backfiring (this has only happened once) I am at a loss. Carb Rebuild was next on my list, but what am I missing? Cam? Compression? Fuel Pump?
Back firing When I hear back firing or poping on my carb its usually a vacume leak. I hear it when i'm going down a hill in gear but not pressing the gas. I use a can of carb cleaner or electrical cleaner and spray it around the base of the carb and if it revs up its a leak and you gotta take it of and make a good gasket with a little permatex. But you've got an older stock carb and those are hard to rebuild.When it bogs does is put out smoke?Is this a 22r?
first off, i need some pics of your dually!!! secondly it sounds kinda like what mine was doing when my fuel pump was going and or gone. Is your pump a mechanical one? if it is, check n see if its pissing gas out the lil hole that faces down on it.
