I'd recommend you do a battery test and charging system test. The battery would be my first suspect.
The starter or battery could be weak. The weakness will cause the starter to turn too slowly to start the truck.
Sounds like a starter issue. Bad wire to the starter could cause it.
Remove and replace the starter.
the solenoid is bad on the starter. soon after this problem starts tapping on the starter will not work either any further questions email me at crazyarmydad@hotmial.com
The starter solenoid is bad.
on top of the starter
The starter for a 2002 GMC truck is located on the passenger side of the block by the transmission.
Could be a shorted wire, or bad battery.
There is no such thing as a 310 Chevy truck.
There is only one starter per truck. If you follow the positive battery cable from the battery it will lead to the starter.
starter solenoid is connected to top of starter
This truck uses three different engines, all with slightly different starter mounting. All starter replacements are pretty similar though. Most importantly you must first disconnect the negative battery cable. Raise and support the vehicle. From under the vehicle remove the large and small power wires to the starter. Remove the starter mounting bolts Remove the starter. Reverse procedure for installation.