1999 Dodge Ram Truck will crank but won't turnover

I have done everyting I can think of to get this truck started. I have changed spark plugs, distibutor cap, rotor new wires. New coil and ignition pickup coil. I have checked the timing and it is right on. Still won't start. I did notice that when I was putting the truck back together from the pick up coil the plug to the computer was undone so I replugged that back in and unhooked the battery for an hour and hooked the battery back up and still would not turn over. It does crank. It is getting plenty of fuel.