Guys (and Girls I guess),

I have a 2005 F150 with a 3v 5.4 engine. It only has 71,00 miles on it, but now I'm having a misfire issue. It only seems to happen when I'm accelerating rather hard. Under normal acceleration it usually isn't noticeable. The guy at the ford dealer immediately said Coil Pack issues.? Thats why I got on here and started researching it. I have noticed a few times if I get it to stutter, for lack of a better description, when I really slam the accelerator down, I have gotten a back fire in the intake.??? Any and all help would be appreciated.

PS. I run an Edge Evolution tuner on it (which is set to factory right now). Could this be the reason I'm having issues?
I have always been a Ford guy to the core, but this damn truck has already cost me a new exhaust manni to the tune of $300 dollars and now this, which who knows how much this will be.

 

Bump.

Please help if you can.

 

Have you checked to see if you have any codes? Also, do you have an aftermarket intake?

 

With 71k you may need spark plugs.

 

Yes, I have a cold air intake from XDI. I just cleaned it recently, so it shouldnt be an issue. I wouldnt think. I used my Edge programmer to check for codes, but it shows nothing. Now ever since I have had it installed(couple years) occasionally it will show each bank being lean. But I figured that was the level of program I was using that caused that. Now its showing nothing.

 

I think you just hit on your problem. The 5.4 3v for 2004-05 in stock condition runs in a near lean condition. The Edge programs are written for a stock intake. You've been running lean. Just hope you haven't burned some valves. You need to get that intake off or get custom tunes.

 

I'm running the stock tune right now. Still not showing a lean code. This misfire\whatever it is stuff has just started in the last few months. It only shows up when I start getting pretty deep into the throttle. On the way home from work this a.m. I pulled away from a stop sign and laid into it all the way to the floor (gradually and steady). When I hit 70, i let off. Nothing happened. Maybe a hiccup at the beginning but nothing else. ??

I am thinking of having all the plugs replaced and changing out the fuel filter, along with anything else that I can think of that would be relatively low cost. Just to see. What do you think?

 

I would do plugs as they could be worn a lot faster from running lean. Weak plugs cause stress on the COPs, so one or more of thse could be going out, but I would wait and see on them. Just hope you have not burned some valves. Running lean takes some time to do it's damage, unless you are so lean as to cause an immediate problem.

Running a stock tune is not solving your lean problem. You need the stock intake or a custom tune for the CAI to avoid running lean.

 

I have a 2000 F-150 with a K&N intake and have noticed that I have the same problem sometimes. It started recently, but I get the check engine light when it happens. The code says I'm gettting a misfire on cylinder #4 then the light resets almost immediately after I let off the throttle. I just changed my plugs about 15K miles ago.

 

I had the same EXACT issue as you. I also have an 05 5.4L with 73k on it. I changed all the plugs and coils couple weeks ago and that problem went away. Got 8 coils from uneek on ebay for $115 and the motorcraft plugs from summit.com for $6-7 each. 71k miles on it means new plugs, coils, and fuel filter.

 

I just posted this same problem last week on my 05 with the 5.4 and pretty much same mods but only 27K miles. I was having the same issues except mine was also sputtering at cruise speed.

BlueJay suggested cleaning the MAF which took care of the issue at cruise but still cut out when you got on it or pulled a grade. Thinking it might be an injector or coil issue I went to the dealership hoping it would be covered under my extended drive train warranty. $400 and 5 spark plugs later it's good to go.

 

If you have a CAI, I bet it's running lean and destroying the plugs prematurally.

 

Bluejay, would the outside air temp with the CAI have any different effect on it ? The reason I ask is that I have had the K&N on it for over two years with the canned Superchips programmer and never had a problem, now that the temps have dropped it fried 5 plugs. I also only put about 5k miles on a year so that I am sure that plays into it also.

 

REMOVE that CAI or get custom tunes! Doesn't frying 5 plugs in 27k say SOMETHING to you?

I'd personally remove it and do a DWV/Gotts mod to the stock airbox.

 

Hey guys, I'm new to this site but have always been a die hard Ford fan. Until recently anyways! I've been having the same problem as Fakout however I have absolutely no mods, chips or upgrades whatsoever. I have the 2007 FX2 with the 5.4l with 80k on it. Ford has replaced all of the spark plugs and coils in this past year MORE THAN once on each cylinder and they tell me to just come back when it happens again. Honestly it's getting old and I'm just looking for a solution as to WHY this is occuring instead of putting a temporary fix on this issue. Any suggestions? Thank you to anyone that can reply, your time and opinion is greatly appreciated! On a side note, this problem occurs under mild acceleration and almost always on hills or when I happen to be hauling materials for a job. Should have just bought a camaro at this point.