Will not start after overnight

99 Dodge Ram 1500, 4x4, 5.9L, 76,000 miles. Has become very hard starting though once it has started once truck will start fine throughout the day, truck is very hard starting after sitting for 8 hours or so. It has fire, turns over without any problem but will not start (like it is not getting fuel). While hard to start it usually it will finally start after several cranking tries of an extended period (15-20 seconds), the engine coughs and then fires though it may have to be left for a 1/2 hour or so and then when tried it may start. Once it starts once, it then starts fine after that thoughout the day. Today, however, it will not start, just cranking with almost no attempt at firing (a slight cough after a couple tries). The check engine light has been coming on for a couple of weeks with two error codes: Ignition/Distributor Engine speed input circuit malfunction, and, EVAP emission control system purge flow fault.
Many friends tell me its the fuel pump but I would think it would give me trouble throughout the day as well. Any suggestions what the errors codes mean and how to correct will be greatly appreciated.