96 4.3 haunted

96 jimmy 4.3 litre does not want to start sometimes after sitting overnight. Changed injectors,tuneup, everything but the kitchen sink. The question is could it be fuel pump or crankshaft sensor?

Do a fuel pressure test, it should be 60-66 psi with key on and engine off. Did you happen to replace the fuel pressure regulator? Try turning the key on, wait for fuel pump to quit, turn key off for 8 seconds and turn to on again and see if it starts right.

60+ pounds and holding, fire may be weak, changed coil, and complete fuel rail and regulator. tries to crank but kicks back like timing way off.
Any ideas??

You might have jumped a tooth on your timing chain.

Have you changed the fuel filter?