99 yukon not starting

Hello all,
Here we go again my 99 yukon has been giving me problems starting for a while.Now it won't start at all it just cranks and it has spark and fuel pressure at first when it would give me problems I would jump it and it would always start which diddn't make sense because the battery was strong any ideas?

Thanks

You're going to have to check your fuel pressure and fuel volume. Fuel pressure should be between 58-62psi at idle and at prime. If it is not, there is not enough pressure to pop off the injectors.

how strong is the spark? check cap and rotor. ohm out coil.