HELP!!!!! I have a 96 Suburban 7.4. I was driving a month ago and stopped at the light. When I pushed the gas it lunged and quit. I have changed the timing chain and gears, Plugs, Wires, Cap, Rotor, Cam Sensor, Crank Sensor, Fuel Filter, Fuel Pump and have no change. It acts like it wants to start but it will not fire. I have 56 psi at the plenum with the new pump. I am not getting any codes when a plug it into a code reader. Any suggestions as I am stumped.