Have the 5.4 in my truck, it’s been a pretty good engine.
Except a problem been having for awhile, when I step on it.
Worse from a dead stop or low speed, like accelerating on to the freeway.
Sounds like it’s backfiring through the intake, have a hard time getting up to speed.
Have to feather it, then it will go.
Took it in, they didn’t see any codes, just been living with it.
Any ideas?
Thanks
Sounds like a weak coil pack. Under heavy throttle, cylinder pressure creates more resistance across the plug gap, and a marginal coil can’t keep up, thus an intermittent misfire. Because it is so intermittent, might not throw a CEL. My Triton V10 Ford E-350 had the same issue. Misfire under throttle, ok under light throttle / cruise.
The Ford coils are very cheap - many of the Modular motors use a Motorcraft DG-508 and they used to be under $20 each.
How do you locate the bad coil pack.
On second thought, will just replace all of them.
Have to shop around, O’Reilly’s wants $66.99 ea. for them.
You would have to use an ohm meter and check resistance between the two pins on the plug. I don’t know what the spec is but Google might turn it up. I would just replace them all. When I was running the 5.4L during it’s development replacing the coils was very common to keep it running smooth. Of course, they were prototype parts at that time so not a fair comparison of what you have in production on your truck.
Also try running a higher octane fuel…
I have to replace plugs and coils at about 75K miles on my 2005 5.4 F150. IT had all kinds of little stumbles on and off throttle that did not throw codes.
You can pull the long bottom boot off it has a spring coil that delivers the spark down to the plug. Most times it’s not the coil that goes bad but the connection from the coil down to the plug will get corroded and start to lose contact. You can take them apart and trying cleaning if your on a tight budget. Most likely that is where your problem is and that’s why it is intermittent. They went through several design changes. Like Bill said I would also suggest you change the plugs. I had to run the 5.4L with several different fuels. Running low octane fuel it would foul the plugs. I was running it 40% beyond the extreme conditions that it would ever see in a vehicle.
Did you tackle the plugs.
Everything I’ve read, sounds like a PITA.
Any break?
Interesting.
About anytime I step on it, it sputters.
My wife even said, your truck sounds like sh!t. Can’t have that.
The other day I got passed by a little Nash Rambler.