Bacon35

My 2006 F-150 with the 5.4 triton engine has around 170,000 miles on her. I’ve done all the routine maintenance myself, but haven’t changed any major parts or sensors since owning her, other than routinely changing the spark plugs and brakes. I also have recently change my fuel filter and air filter. I bought the truck with 90,000 miles 11 years ago.

Recently, I went from averaging 14-15 city mpg with a powerful acceleration with rpms around 1300-1500 to a sudden drop to around 9-11 city mpg, and sluggish acceleration where I’m finding myself having to push well above 2,000-2300 rpms just to get up to speed.

I have no CEL, no underlying codes when I connect my scanner, all my fluids are good with no indication of one leaking into the other, I’m not burning oil. I’m thinking either a sensor is going bad but hasn’t gone “bad enough” to throw a code, the fuel pump/sending unit, or fuel injectors. But for all 8 injectors to go bad at once seems far fetched since my idle is fine.

Has anyone else encountered this or have any suggestions on where to begin or troubleshoot this issue?

Rambo 2

Could be a spark plug coil? Too many suggestions to figure out what yours is without a code. Let it go empty. Pour a bottle of Techron concentrate in it. Fill it with Top Tier gas and see if that improves it.

techrep

iTrader: (1)

have you ever... replaced boots and springs during plug swap... cleaned throttle body... cleaned MAF sensor.. do the diamond bird ...

Crett

Coil Packs would be my first guess. I would definitely recommend cleaning the throttle body with a cleaner like CRC Throttle Body Cleaner. I just changed the plugs in my '08 5.4 Triton and it only has 84k on it and the throttle body was pretty gunked up and dirty.

techrep

iTrader: (1)

If a coil pack is bad ...it will toss a code or flash your CEL under heavy acceleration .