Loosening any lines at all on a Roosa Master pump shuts it down completely. Putting any fuel into the intake will result in the engine trying to run backwards and probably bending some connecting rods. Definitely don't try starting fluid!
Just tighten everything down, and crank the engine until it fires off. Make sure the mechanical boost pump is flowing fuel to the injection pump, and don't fry ther starter! It will start, eventually.
Jerry
