Backfire under heavy acceleration

[tortega8]

I have a Gen 2 2019 Ford f-150 raptor, 70,450 miles on it. Lately I have encountered some backfiring issues when I am accelerating. It usually only happens when I start from a stop and accelerate heavily or when I am at higher speeds on the highway, usually between 75-85, and step on it. It does not seem to lose power but it does this kind of sputtering/backfiring under those conditions. I started with changing the spark plugs to NGK laser Iridium plugs and gapping them to manufacture suggestion which is .030. That did not solve the problem. I then got the error code P0304, which read a misfire in cylinder 4. So I replaced the ignition coil with a motocraft one from a dealership. This seemed to solve the issue but the I went to work one morning and got stopped at a light and decided to see if the problem was truly fixed. I stepped on it and after heavy acceleration it backfired again. I am at a loss what to do right now. I am not getting any check engine lights, and the truck idles fine and drives smooth. If anyone else has this problem, please let me know what the next steps you took to fix it or what I might try next? I saw some discussions about trying to run 93 octane in it with fuel injector cleaner. So that is my next step is to put 93 octane and add fuel injector cleaner into the mix, even though I do that regularly, and see what happens. Please let me know what you think, things I could do next, if you had this issue or how to fix it. Any knowledge would be greatly appreciated!!! Thanks!!

 

[faptortheraptor]

I’m getting the same thing. Replaced with motorcraft plugs from Winston gapped it at 0.26 but I get cylinder 6 misfire.

 

[tortega8]

I’m getting the same thing. Replaced with motorcraft plugs from Winston gapped it at 0.26 but I get cylinder 6 misfire.

I did the same thing. Then I replaced the ignition coil where it said a misfire was occurring and I am still getting the same issue. I ran fuel injector cleaner through the system and ran 93 octane gas in it to see if that was the issue. Problem is still occurring. Next I am going to look at the O2 sensor maybe replace that or the fuel filter? Not sure what to do next.

 

[EricM]

The term you are looking for is misfire- not backfire.

The typical way to find if it's a plug vs a coil is to move the supect coil to another cylinder to see if the misfire follows the coil being moved.

 

[tortega8]

The term you are looking for is misfire- not backfire.

The typical way to find if it's a plug vs a coil is to move the supect coil to another cylinder to see if the misfire follows the coil being moved.

Nope, definitely backfire at this point when you replace all ignition coils and spark plugs. Thanks for the input!

 

[Gumby]

Nope, definitely backfire at this point when you replace all ignition coils and spark plugs. Thanks for the input!

Backfire is usually caused by timing. something going on with the cam phaser possibly?

 

[MurderedOutSVT]

 

[Chewie]

Backfire=timing