My 6.2 suddenly decided not to start, luckily in my driveway. Ran & started perfectly since new GP's about a month & 1/2 ago. Than today - cranks fine but no start. GP' cycle OK. I'm not getting the smoke from the tail pipe I'd normally get when I turn it over. Could this mean injector pump? It was the first attemped start this morning after sitting all night. Ran fine last night. Any help is appreciated. TNX in advance.