F250 engine missing/ new ignition coils

Maintenance/Repairs
1

Hello all,
My 2002 F250 Super Duty 5.4 is driving me nuts.
It had a problem where the engine would miss, the engine light was on, the ABS light would flash and the speedometer would jump during acceleration. This was remedied by replacing all of the ignition coils.
The next week the problem started again but was worse. I had seven cylinders misfiring with all the same symptoms. One plug was found to be sparking either very weekly or not at all. Replacing this plug solved the problem for two days.

Now the engine missfire has started out very slightly, but gets a little worse every day. It is most present when starting the engine cold and I can detect it when accelerating well on the freeway.

A little over two years ago I had this exact same problem and replaced all of the coils and plugs. This time I only replace the coils (that is what the diagnostic said was wrong) due to a brand-new set of plugs being installed with a replacement Jasper engine two years ago.

Is this a domino affect with the plugs? I’m tempted to just buy a whole new set of plugs and go to man, but I’m tired of wasting money. I did replace the mass airflow sensor and the speed output sensor on the transmission as well.

Tired of chasing this ghost and I need my work truck to work.

Thank you!
Todd

2

I know you have a newish Jasper engine . . . but is the compression good?

I would hook up a fuel pressure test gauge and an injector balance tool. I’ve replaced a few bad injectors on these engines. the injector coil was open. the great thing about the balance tool is that you can not only activate the injectors individually, you can also hook up the multimeter and check the resistance of each

Is the check engine light flashing?

What brand plugs and coils did you install?

Did you also replace the coil boots?

Another thing to keep in mind . . . the plugs have a tendency to literally blow out of these engines, taking the coil along with them. Might want to make sure this isn’t about to happen