Hey guys, new member here, been reading what I can though. As the post says I was getting a misfire in #4 cyl. Couldn't afford to change all my plugs, so I replaced the one that was missing. Two weeks went by, truck ran fine, then it started missing really hard (same cyl #4). Thought my COP was bad, so replaced that and the boot. Drove my truck to work last night, seemed to run fine, but this morning, it started to sputter again around 45-55. Plug in my OBD2 and it wasn't throwing any codes, seemed to idle just fine. When I got home I put it park and revved the engine a little bit. Got it around 2500 rpm and it sounded like I have a air leak in a way ( I know explanation is ****ty). I have no idea what do at this point. It is a 2007 F150 5.4 triton with 104xxx on it. I know this has been brought up many times, but I'm all out of ideas.

Thanks

 

That sounds weird. Check cylinder #4's coil plug connector and wiring. One thing I've learned too in the past few weeks..... Do not put different brand coils on it. I had bad misfires for a while until I replaced all of the coils and plugs. There were 6 motorcraft coils on it, one that had zero markings on it (the ford dealership replaced it), and one that I believe to be a master pro. I was reading misfires in 5 of my cylinders. I put the motorcraft coils in place of the two weirdos and the check engine light went off. Sadly they weren't mine so I went to O'Reilly's and bought a set of MSD coils because they were the cheapest for all 8. Yeah the best coils were cheapest for all 8. The thing runs like a bat out of hell now. I hope this helps you.

 

I only changed the one coil and the brand was Valucraft as it was the only one they had in stock. I watched a video on youtube of a guy who had a similar problem, and he said his sputtered after he changed them out, but it went away. I only live a short distance from where I work, would it be ok to drive to and from work until they can get another motorcraft in? I don't start shool until the second week of may, so the only place id be driving to is work.

 

You'll be okay driving it with the misfires, just take it easy. Gas mileage will go down though. But get a new set of coils when you can. I found its cheapest to get a full set of MSD coils from O'Reilly's Auto Parts. MSD is a good brand, people talk bad about them a lot on here but nobody I have ever talked to in person has nothing but good things to say about MSD.

 

A few years ago my 2004 Expedition presented what felt like a misfire but ended up being a vacuum leak.

Additionally my 2011 F-150 started misfiring a bit last week. The primary culprit was a #2 misfire even though the dealer's diagnostic showed a random misfire. Replaced all six plugs and boots and all is well.

 

Thanks guys. When I start the truck it doesn't sound like there is a misfire though. I'm going to go out tonight and see if I can see sparks coming off the wiring. I checked the connections and all seemed fine. I'm confused on what this could be. I'm still getting no code being thrown, een after driving the truck and idling and revving the engine. It doesn't shake more than a normal engine would while idling or anything.

 

scratch that about it not shaking while revving it in idle. I let it idle again while checking for sparks from the wires, ran fine. Revved it before I shut it off and it started to shake pretty noticeably around 1300-1400 rpm. Not sure what it could be, its still not throwing codes.

 

Went through something similar on an old Taurus. It would shake at speed and it also pinged quite a bit. Wasn't a vaccum leak. Changed plugs, coil trying to track down the misfire.

Turns out it was a bad EGR sensor (DFPE?) causing it to always let too much exhaust in. Never thought to replace that until I got the code for insufficient EGR flow.

it can be bad for a while and cause issues for a few years, apparently, before it is bad enough to set the check engine light.

 

I'm pretty much thinking it is no longer the plug and coil. I haven't ruled out misfire at all, but I am lead to belive that it is still a air/fuel problem. A buddy of mine at work is thinking that with it bucking around 40-50 around the 1300-1500 range to get back up to speed and while being revved at all idle that it may be a throttle postion sensor. I read the symptoms and it could be the problem. I will also be pulling off the mass airflow sensor and seeing if it is dirty at all. I'm not at a complete loss for what it could be, but I wll be putting the EGR sensor on the list. I just drove it to pick up my daughter from school and all seemed fine. I did noticed that it does idle around 900-1000 rpm while sitting, not sure of this is normal idiling rpm, but I did notice. It kinda seemed that it would slowly increase or decrease. Thanks for the input, keep em coming, I'm applying everything you guys are telling me and ruling out what I can. I know my truck is 9 years old, but I'm sure people who buy used may run into similar problems.

 

No need to do that. Your '07 5.4L doesn't have one at all.


The low (1150-1500) RPM misfire has driven many 5.4L owners to drink. I developed a THEORY about the issue that solved the problem for me and has kept it from returning - over 213K miles now. The unique design of these engines that leads to spark plug breakage on removal - I believe is also related to the difficulty in isolating / removing random misfiring. I explain my reasoning in detail in this thread: https://www.ford-trucks.com/forums/11...l#post15819897


And after lots of research into how this design feature relates to "heat range" of spark plugs is detailed in this discussion on another forum:
5.4 issues - misfire - F150online Forums

IMO, throwing parts at it won't help. Thousands of COPs, injectors and other stuff has been needlessly replaced (OH, on my truck TOO!) because of other sneaky things that we inadvertently cure while goofing with other things replacing perfectly good parts. Since I started taking care to keep the cylinder head carbon OUT of contact with the extended plug snouts, WITHOUT using antiseize, and using (a moderate application) of dielectric on really CLEANED or NEW boots, and clean secure electrical connections, I have never had the problem again.