truck runs for 20 minutes then it stop Icheck the relay they work what can i do

Sounds like a bad crankshaft position sensor. If it is cracked as the car warms up it expands causing a faulty reading.

Possibly intermittent CKP Sensor. Check you Crankshaft position sensor wiring and connectors. This sensors input to the Powertrain Control module is what supplies the voltage to the ASD relay to power up the injectors and Ignition.