misfire, lack of power on highways and hills
I have a 1988 Dodge B250 rv conversion with a 318 engine 116000 kilometers. Fuel filter,fuel-pump and sock,spark plugs,wires,distributor cap and rotor, coil and magnetic coil in distributor all changed. No engine codes. Mechanic said good spark and fuel injectors. When i am on the highway and give it gas it is like a miss and no power. I noticed more when under load like going up hill. The vehicle will shake and loose some speed if i let up on fuel will go away. Mechanic said he took it for a long ride and no problem and said wait until it happens all the time. Tired of paying for parts and no change. Any help would be appreciated.