2001 Dodge Truck 5.9 engine won't start

The engine wont start. fuel PSI is approx. 50 psig. at first it would start if I sprayed starting fluid down the carb, then I also lost the spark. I changed the cam sensor & crank position sensor, The TPS reads in proper ohms range as required. what else could be causing my problem. I never used this site before so I am starting out with 1 free question. If I like the results, Ill be Back! Thanks~ Steve Dodge