Cylinder 5 Misfire, Have Tried Different Solutions, 5.4 3v
08-19-2017, 03:33 AM
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Cylinder 5 Misfire, Have Tried Different Solutions, 5.4 3v
Good afternoon, I have a 2004 F150 FX4 with the 5.4 3v engine. Anyway I have a misfire on cylinder 5 as that is what my scanner tells me.
A little backstory: I purchased this truck about a month ago. Everything was working fine, took it to Pasadena and back and had really no issues but poor MPG, something like 11mpg and it was all highway so that is obviously an issue. My first guess is that its been a while since the plugs were changed. So I remove the plug for cylinder 5 and it looked like it hadn't been changed in a while. No misfires up to this point. I put the plug back in and turn it on a couple days later. It ran like a paint shaker. So I assume the plug went bad but on the weekend I put new plugs for all 8 cylinders and it was fixed! Engine ran smooth. Fast forward to the next weekend and it starts misfiring on cylinder 5 again. I change the COP and Plug with one of the other cylinders and still the same. Interchanged injectors and still the same cylinder misfiring. It runs and idle extremely poorly. CEL is on and flashes if driven. I tested the spark from the COP and the spark appeared normal.
My question is, what else is there to check or try? I feel like I have tried the most common fixes but they seem to have had no effect. If anyone has any idea on what it could be or any possible solutions, all will be appreciated.
I can pull the live data from my scanner and all the codes if need be.
Thank you!
A little backstory: I purchased this truck about a month ago. Everything was working fine, took it to Pasadena and back and had really no issues but poor MPG, something like 11mpg and it was all highway so that is obviously an issue. My first guess is that its been a while since the plugs were changed. So I remove the plug for cylinder 5 and it looked like it hadn't been changed in a while. No misfires up to this point. I put the plug back in and turn it on a couple days later. It ran like a paint shaker. So I assume the plug went bad but on the weekend I put new plugs for all 8 cylinders and it was fixed! Engine ran smooth. Fast forward to the next weekend and it starts misfiring on cylinder 5 again. I change the COP and Plug with one of the other cylinders and still the same. Interchanged injectors and still the same cylinder misfiring. It runs and idle extremely poorly. CEL is on and flashes if driven. I tested the spark from the COP and the spark appeared normal.
My question is, what else is there to check or try? I feel like I have tried the most common fixes but they seem to have had no effect. If anyone has any idea on what it could be or any possible solutions, all will be appreciated.
I can pull the live data from my scanner and all the codes if need be.
Thank you!
