97 engine fuse blows as soon as you turn the key on but truck will still run great but after awahile the ecm fuse blows the it dies put another fuse in ecm and it starts right up and drives away for and the blows again

Welcome to AF
A lot of engine sensors and wiring on that fuse.
Get a wiring diagram of that fuse circuit and start checking sensors and sensor wiring for shorts.
Is it setting any codes?