After many trouble free miles and years my Zetec just shut down. A quick second gear blast in town, then on the brakes for a stop sign. The engine dies, I let the clutch out, it tries to restart, sputters then quits. Checking it at home the plugs are fouled. I replace them. I have spark. The fuel pump runs. The engine refuses to start. The engine is a 2.0l Raceline injected using GEMS management system and stock Ford sensors. My Mychron tach reads strange RPM's when cranking. Could it be a faulty crank sensor? Before I start throwing parts at it I would really appreciate some Blat Chat wisdom. Thanks for the help.