Ford Owner 08

I have an 08 Ford F150 5.4. When we hook the computer up it shows misfire in 2,3, and 4. We have tried new fuel injectors since someone suggested that. The truck runs, just doesn't have any power. We have also changed the fuel filter. What should we try next?

graywolf

Do you know when the spark plugs were changed? I had a misfire when the truck was first started and going up a slight grade...never any other time....couldn't be the plugs, right? Wrong. I changed the plugs and it ran like like a scalded dog afterwords...never a missfire. There are videos showing how the change the plugs. And you will need the Lisle plug removal tool (about $60 online) to remove any broken plugs. I had two break but got them out with the tool.

GREEN16

You may need to replace the ignition coils on those cylinders. An easy way to test would be to swap the coils from one side to the other and see if the misfires follow the coils.

powerranger262

Throwing injectors at a misfire? Did you pull any codes that you could post here? Hopefully they had something to do with injectors, otherwise "someone" wasted your money.
Like said above, swap coils, and see if the misfire follows.
How many miles on the truck?

Ford Owner 08

The codes showed cylinder #2 &#3 misfire. The truck has just over 100,000 miles on it. We have not changed plugs yet. We are going to swap coils tomorrow and see what happens. Thanks for the help.

powerranger262

Do some searching on plug changes on these trucks before you dive in. Lots of YouTube videos that will help.
What engine do you have?

techrep

iTrader: (1)

He said 5.4.. so you have 100K miles on it and never changed the plugs and you are wondering why you have a mis-fire ?

powerranger262

Seeing as though you have an 08, you will have the updated plugs, so you shouldn't have a problem.
Here's how I did mine, and it was a breeze.
https://www.f150forum.com/f4/wow-did...-plugs-366780/

powerranger262

Also, get Motorcraft plugs, and change the boots and springs also.