I have a 4y that has @180psi in all cylinders. Turns over fine until you turn on the fuel and than it act like it hydro locks. We have 2 trucks a this facility and have swapped distributors, changed plugs, checked timing numerous times, and have pulled intake and exhaust. Nothing seems to change it. The symptoms stay the same and the other truck is running fine with this trucks parts. Any suggestions would be appreciated.

Thanks