1991 F-350 460 efi I have #4 plug out and it's dumping gas. Ive cleaned all 8 injectors, I switched #2 and #4 around. #2 is not dumping gas. #4 still dumping. Disconnected #4 electric and #4 is still dumping fuel. Can't get truck to start. With #4 spark plug in, it hydro locks from all the gas flowing. Pull #4 plug and the motor will turn, but spewing gas every stroke. Any help???

 

You my have a plugged fuel rail. Your fuel feed crossover is at the number 4 injector. Pull your fuel rail and disable the coil. Remove number 1 injector and turn your key on. See if fuel dumps out at number one location. Then install it and pull number for and compare fuel flow a month between the 2.

 

Or it's due to the signal from the ecm. I would need an oscilloscope or at least a meter capable of measuring the duty cycle to find out if the ecm is incorrectly holding that injector open.