So, I battled a misfire for about a year and a half before figuring out the simple cause of it. I pulled up and down on all of the coil packs without even unscrewing them to make sure they had a good bite on the spark plugs in case there was some buildup, (they still have some play when they're screwed down) and I have been good for about 5 months now. After replacing the fuel filter and doing fuel treatments, replacing one coil that threw a code (twice in the course of a year and a half it actually misfired bad enough to throw a code, the rest of the time it was just an intermittent sputter while cruising, poor mileage, and a slight rumbling while accelerating) and every other inexpensive thing I could think of trying. I refused to start replacing injectors and coil packs and spark plugs when they actually looked good and I had no real evidence of what was bad. I just dealt with it hoping it would become bad enough to throw a code, which only happened once and the issue never really got worse. So on a whim I decided to reseat all of the connectors on the coil packs and injectors, then I thought about carbon buildup tween the coil packs and spark plugs. That's it, I just wanted to share my experience of the stupid, $0.00 repair that was the culprit of my misfire... A bad connection due to carbon buildup.

 

@coupedehille


Thanks for sharing your success story - one of the 'umpteen' things that can result in a misfire on the 5.4s that isn't even a spark plug or COP. I bristle every time I read a post that JUMPS immediately on advising "replace the COPs". If the poster takes the advice - he spends a load of money and either still has the problem - or 'inadvertently' corrects the REAL problem (like yours) without ever knowing it. Then goes out and perpetuates the "REPLACE THE COPS" story.

 

@F150Torqued

Thanks for your great posts. I'm going to do the spark plugs on my 2009 f150 with the 5.4 v8.
What are your thoughts on the NGK 5507 double platinum plugs or the NGK 1698 single platinum plugs vs the motor craft SP-509? These both show as an oem replacement but I'm seeing lots of posts saying to just stick with the ford motor craft parts. I know Autolite manufacturers plugs for ford but they don't have a cross reference for the SP-509(12mm thread diameter),closest is the SP-507 but it's a different diameter(16mm).
The dealer here wants $23 a piece for them here in Canada. The dealer quoted me $350 plus tax just to swap out the plugs,another dealer wanted $500. I'm going to do it myself and clean out the carbon as you did. Just curious if anybody out there has had good results with the NGK's in their 2009-2010 5.4 engines? I see the gap spec as you stated is between .039-.043, The SP-509 comes gapped at .041 and all the oem NGK's are showing .045 I'm leaning towards just getting the motor craft ones but was wanting anyone with experience to chime in.
My truck is sitting at 199,000kms, it's running a little rough under load(not towing),not really missing but a sort of sputter between 1900-2300 rpm's. I'm hoping plugs may smooth it out?
I bought it used with 190km's ,have been driving it since nov/2015 and am pretty sure previous owner didn't do anything but oil changes to it. She feels a little tired.

Thanks guys

 

Rockauto.com ships to Canada. SP509's are $11.07 CAD plus shipping. If those are original plugs in it, they are very overdue.

 

@glc
I'm not sure if the plugs in it are original,I am guessing they are and am hoping that is the issue with the roughness/sputter under load.
I have spent a lot of money on it to get it freshened up:
Brakes,tires,shocks,tranny fluid and filter replacement,synthetic oil change,brake fluid flush, a few pulleys and belts replaced, new battery, RH blend door actuator, pax seat frame and motor,windshield, heater blower motor. All in it's north of $4500.
I ordered the motor craft SP-509 from rock auto.com today(thanks for that) and will post my results after I complete the job.
Any other ideas as to what may make the old 5.4 run better? ( don't say get an eco boost or the 5.0)

 

If it still runs rough after changing the plugs, you may need some coils.

 

Thanks for the advice. It may be a few weeks before I get the plugs and get it done. Hopefully it's just the plugs.

We will see?
I'll let you know how it goes.

 

Hello,
I've got 2009 F150, 5.4 L engine with 199,000kms(123,652 miles).
It idles fine both cold and once warmed up.
It seems to sputter slightly under load between 1600-2000 rpms. (This is while going up a hill empty.)

I've changed the plugs, done a coolant flush,tranny flush with a new filter,cleaned the MAF and the throttle body. Fresh oil change and transfer case oil. The truck has an AFE cold air intake as well as a cherry bomb cat back exhaust system. I've had the truck for 1.5 years and got it with 180,000kms. It's got a solid maintenance history with regular oil changes.
I cleared the PCM'S memory after doing the throttle body by disconnecting the negative battery terminal and adding a jumper cable to the positive and negative cables and letting it sit for about five minutes. Reconnected everything and let it idle for about twenty mins to reset the idle limits of the throttle body. I basically followed Fordtechmaculoco's you tube videos for that:

I also used his youtube videos for the throttle body cleaning and coolant change.


I'm not getting any codes. I did get a code about 9 months ago but it's not there anymore and I can't remember what it was exactly...I think it was airflow sensor or something?
The only thing I still plan on doing is the front and rear differentials but I don't think that will have an impact on this weird issue.
I don't know what else to do?
Could it be dirty injectors?
I just put a bottle of lucas upper cylinder lubricant with injector cleaner yesterday and need to run it for a few days and see if that changes anything. I'm still getting that weird stutter/hesitation between 1600-2000 rpms when it's under load. It's not that noticeable but it's definitely there. After all this maintenance I've done it does seem to run a little bit smoother and the tranny seems to shift a tiny bit smoother. I'm out of answers.
If anybody has had a similar issue and was able to fix it,please let me know.
Cheers everyone.


Any other ideas or advice would be great.

 

Here are the other videos I found very useful.
This guy is great and he was a ford tech for many years,he's got his own shop now and drives a ram ecodiesel, go figure?

 

Did you replace the coil boots when you changed the plugs? Did you use dielectric grease?

 

I did use dialectic grease but did not replace the boots. They looked to be in good condition,the plugs didn't even look too bad. I was able to get the maintenance history as well....some of it anyways. The plugs were replaced once before at 90,000kms. So the plugs I removed had about 109,000kms on them. I'm thinking it may be the injectors but I'm not sure how to get at them. Is it safe to spray them with throttle body cleaner or should I use the MAF sensor cleaner?

 

Neither. Use Techron in the gas and/or pull them and get them bench cleaned and tested.

 

@glc
I'm first going to attempt to do a resistance test on the injectors as well as the COP's.
I know this doesn't give me a complete diagnostic as it's just a static test but it might show if something is off in that area of OHM's. Unfortunately I don't have a scan tool capable of doing a power balance test.
I don't want to start replacing injectors or COP's unless it's necessary as I'm already knee deep in spending and want to curb that part.

PS: How did the clutch job on your buddies truck go. It was a clutch wasn't it?

Thanks again for your suggestion. I'll try cleaning and/bench testing them if the resistance is bad in any of them.

 

oh and buy locktight..put it on inside of thread and outside of thread..that keeps it from blowing out and leaving thread in the head..that is another bag of worms.

 

What on earth are you referring to?