How can I start my truck?

I have a 1998 Ford F150 v6 and was running good until all of a sudden one afternoon it cranked but didnt turn on. I checked all the basics like battery, fuel intake, fuel filter, spark on plugs and so far good. I even sprayed starter fluid in to the intake and no luck. It will start if I floor the gas peddle but hakes and intake pops as if the timing were bad or something. Could it be a sensor of some kind.