engine runs rough/missing on 2005 Ford F-150

when accelerating the engine misses really bad. If I back off the gas pedal it seems to smooth out some. It does not do this all the time but when it does it is when I am accelerating.

by in New Bern, NC on November 10, 2009
3 answers 2 comments
ANSWER by on November 11, 2009
You should have a check engine light on and codes stored in the power train control module. Can you get these codes and post them?
COMMENT by on November 11, 2009
munkyrench, engine icon light is on. have not had codes checked yet; will do that and get back to you. mowman
COMMENT by on November 12, 2009
That is a good place to start. Another thing I would do, and this goes for just about every vehicle made after 2000, have the software in the engine and transmission control modules checked to make sure it has the latest available. This can address weird problems that are nearly impossible to solve by regular diagnostic methods.
ANSWER by on May 18, 2010
I am a certified ford tech, and this is a common problem in the 5.4l 3v engine, this engine has overhead cam with variable cam timing (vct), it has phasers on each cam to adjust timing to provide more power or better mileage. but usually after 80k or so these phasers stick so at low throttle or high throttle the phasers stick and are basically backwards from what they should be. they are simple to replace but i would not recomend a DIY because there are special tools to hold timing chain and tensioners in place and if you loose where they are at, then you have to pull off the front cover and re-time the entire engine, most likely your warranty is out, so if you want it fixed then better start saving because it does not come cheap (about 15 bills)..........hope i was helpful
ANSWER by on July 16, 2014
i was having this same issue with my 2006 F150 5.4l and i replace all the plugs and coils and it turned out to be a fuel filter. when you accelerate especially hard the cyclinders are starved of fuel. when you accelerate gently it will not do it all the time right? mine mainly did it between 45-50 mph and 70-85 mph. Fuel Filter is a lot cheaper option. Let me know if this fixes your problem
Related Items:
have replace all spark plugs and coils.problem started after power washing.have check all coils at idle by unplugging connection to coil one at a time all make engine run rough when unpluged
Intermittent rough idle may be caused by the EGR sensor sticking, causing the EGR valve to stay slightly open. Our technicians tell us the valve and sensor must be replaced together to correct this...
I have a rebuilt engine with less than 1000 miles. It was running great than I started getting...
When i get up around 55 mph my truck has a shake in the front end until the engine warms up and it seems like it misses at that speed until the engine warms up.