Help...Can't figure it out!
I just recently had a used/modified 460 put into my '77 F-250. At idle, it idles smooth and sounds great, but as soon as I push the gas peddle down, instantly it coughs and doesn't what to go. If I push it super slow, then it will be fine. I don't know the true history behind the engine but could there be some kind of vaccum leak or something? It has a Holley 870cfm carb, ported heads, bigger valves, stage 3 Comp cams, flat top pistons, bored 30 over, headers, Edelbrock performer intake, new electric fuel pump, new cap and rotor, new plugs. Also, my transmission is not shifting when it needs to. It only shifts at high rpm's and it has never done that before. One last thing, the truck has been sitting for the last six years because of a blown engine. Any input that is helpful would be greatly appreciated.