I'm about to go get a new injector and plug for that cylinder, but then again, I don't want to just keep throwing parts at it.

 

Lean is usually caused by a vacuum leak.

 

Mine is doing the exact same thing as well, but it seems to like the cold air better and does not miss as often. What it also does is during acceleration at WOT, it seems to bog down around 4k and hesitate for 1-2 seconds before continuing. This is about the same place that the misfire comes in when it decides to do so. Usually it's when I get a wild hair and decide to romp on it while lagging around...it doesn't like going in between loping around town and then WOT on a straight away. I have an '05 5.4l with 99,500...

I think it's an overall lean condition on one or more of the cylinders, for whatever reason. I would've suspected plugs (and still do, as most of us are 50k+) and coils but too many are having the same conditions for it to be a random failure. It could be a PCM reflash, but if that were true then any of us with the condition AND tuners could fix this as the A/F ratio can be adjusted to enrich the mixture. I should be getting my tuner with the influx of extra cash from the holidays, so I'll test it out when I get to it. Until then, this may be just another flukey characteristic of the 5.4l that we have to deal with. I think that a proper tune will correct this or else the higher power boys would be having issues as well. Any other ideas?

 

That's crazy that many people are having the exact same issue. I would take it to the dealer, but they want $100 just to look at it. Maybe after Christmas. Any other ideas or experiences would be great.

 

Yea , almost sounds like a re-flash is needed. I would inquire in the other forum on this site.

 

Sounds like im having related issues.. It all started out weird. Parked my truck (running very well) then about 3 hours later hopped in and away i went, only this time my truck was running like major crap.

Under wot it falls on its face hard, back off to about half throttle and it cleans up. I can cruise decent at half throttle but went i need more it backfires, and pops, and stumbles hard. Even pops thru intake tube which freaks me out some.

Its a 97' 4.6l 4x4 supercab

Now i havent noticed any smoke or anything

Fluid Lvls are fine, including coolant. Plug wires are tight, cant locate any vac leaks.

replaced fuel filter 3k miles ago. However i have had this kinda problem before but its always been worse and would throw a miss fire code and was solved by replacing plug wires.

this issue doesnt throw any codes and i think its something else. I pulled a plug and it was kinda on the white side. Seems like its lacking fuel at WOT. Maybe fuel pump going??

All this was while i was running a tune, Once going back to stock it seemed to run lots better but only for a few miles then its back again.

Thought i would give my situation and see if what everyone has to say on it.

 

You have a 97 tho - that's a different set up. Sounds like you have an EDGE tuner .

 

interesting my 04 5.4 had the same issue and went back to the dealer a few times before it got sorted,1st was a fuel filter then they went and found a p0191 code(fuel pressure sensor) and replaced the fuel pump and sensor.it was only running 23 psi.there was another item replaced as well.

has been running great since and have been getting better mileage,now i have the thing in for the 4x4 actuator...its never ending it seams.At least i got a extended warranty.

 

Truth, there is a age difference for sure. Just seemed like the problems were kinda related, and the bottom line is im just looking for opinions on what might be going on. This issue is very annoying.

Also its not an edge. its a custom tune on xcal2 from TP

 

That's a strange sort of problem for the 97. I would think it's fuel related. You might want to go thru it -

 

Hey i like the chart, thx. I have to get a FP tester and see what happens. Between the way its acting and the plugs being a lil white i kinda thought it wasnt getting enough fuel.

If anyone else has ideas. bring'em on..

 

well i picked up my truck last week and just paid the $100 for diagnostics as the bill seemed a bit steep after making a few calls.

700 for a plug change, fuel inj clean and reflash.

A local independent shop quoted 295 for plug change and the guy is a former Ford tech who knows about the plug issues... worst case if they break a plug is a flat $50 fee for 1 or all 8 cyl. this shop saved a neighbor over $600 bucks on a powerstoke repair vs ford so I trust them.

Another option is a buddy of mine is a toyota tech and says we can do it on one of his off days at the shop. But hate to break a plug off at a toyota shop haha...

so with the holidays here I'll prob just for now change my fuel filter again and then after the 1st decide to either pay or take off a day and have some ford fun.

I only drive the truck mostly on weekends heading to the MX tracks to ride my CRF450 soo it should be ok a bit longer...... i hope

 

Anyone else found any fixes for this problem? Could it be just a reflash??

 

Would a reflash be a dealer only fix or would an independent shop be able to do it also?

 

OK, so it warmed up today to 70* from the 20's and 30's and the misfire went away. It seems like the colder it gets, the worse it acts up. It was around 0* last week, and it wouldn't hardly go at all. Could it be a bad or clogged sensor?