Question

2004 Ford F150 5.4L with code P1780. HAVE MISFIRE BAD IN THE CYLINDER 4 CIRCUITO SHORT IN WIRE OF INJECTOR NON-SIGNAL OF THE COMPUTER CHANGED COMPUTER REPROGRAMED AND PROBLEM IS THE SAME

Answer 1

Still no signal after the wire and ECM this would leave you with the harness, Check the terminal ends or replace the pigtail of the fuel injector.