It starts and runs for about 10-15 secs. Then dies. I put about a gallon of gas in (just to make sure). The cables from gas pedal are good and move freely. It just won't stay running. PLEASE HELP. Thank you.

Make sure there is more than a token amount of gas in the fuel tank. Turn the ignition switch to ON, until the fuel pump stops running; then, turn the ignition switch to OFF. Repeat this procedure 2 more times, to ensure the fuel rail is fully pressurized. On the final sequence, turn the ignition switch to START.

If the problem persists, check for codes. Dodge trucks are prone to having problems with MAP Sensors. Another culprit could be the Idle Air Control Valve (IACV)--it may be staying shut and not allowing in enough air.