Pull da cap. Look at da rotor. Turn crank in 1 direction till rotor turns. Then turn in da crank in other direction and sèe how far, or degrees it takes to turn rotor. That will at least tell ya if da timing chain is a sloppy mess. Stretched, gear stripped, or other timing issue? Im not convinced that #1 compression stroke is being verified and-or rotor is pointing at #1 when it supposed to. Theres no way this truck went from good running to inoperable in a flash w/o a mechanical failure if all other necessary components are in place.... Fuel, Spark, ..... the other 2 are Timing and Compression that seem to be questionable?? Unless of course da cylinders are washed down?? Then oil squirting will verify that. Unfortunately like previously stated, maybe da kid needs a better hands on, knowledgeable helper? JMO