800 Ford on propane. Always started quick and ran good until a few days ago when it sputter and died. I pulled air intake hose and sprayed 1 second bursts of starting fluid into carburetor while cranking,nothing,didn't hit once. Installed new points,condenser,coil,copper core plug/coil wires,distributor cap,coil ballast and rotor button. It start's and runs 2 seconds then die's. Chocking and/or strating fluid helps liitle if any. I've kept battery charged above 12.5v and a booster battery on it. I've gone through connections to be sure they are bright and clean,ohmed and checked for voltage drop. Coil has direct power from battery via jumper wire. Propane is not a shade tree project so my main question here is wherether I should be able to keep engine running on starting fluid if everything is right on ignition side. The only propane mechanics around here are forklift places and they just change parts until it run's or the customer go's broke. If I can eliminate fuel as the problem I'll change the ignition parts again one at a time. I've heard people say they got 2 or more bad parts from parts store.