This has happened 2 years in a row first year I installed composite valves .I assumed I did something wrong..Had spark and crank 35 psi at fuel rail . Did an injector spray test . Looked fine. I too a fuel sample at primary filter looked good no water, I took fuel sample at fuel rail .desperate I put small sample in can and threw match at it .would not burn. drained fuel threw sherater valve until I could detect smell of fuel. started and smoked badley . I believe the pressurized oil reserve tank back flowed the gas out of the system. It did the same thing this spring. Not sure why but maybe this will help someone else.
