94 12V does not rev up cold, blue smokes,and fuel mileage is proggresively getting worse. After warmed up --runs great-no smoke-but fuel mileage still bad. Lift pump pressue 22lbs @ idle, maniflod heaters pre-heat & cycle after start up, fuel heater works,air filter good, & timing @12degrees @ TDC. Any ideas? Appreciate any tips. Thanks