this morning on my way to work (5 mile drive) i kicked it down to pass a tractor and right at 3500 rpm it misses/ pops and the check engine light came on. then i slipped her into neutral and reved her up and shes kinda slugish around 3500 rpm, but driving below and above 3500 rpm she seems perfectly normal, and on my way home from work i was fiddling around wiht it and it acted up twice on cycles of slowing down to about 30 mph and kicking her down till about 70 mph. then it was completely fine now no miss or pop. about a week after i got it i noticed it idled just a little rough, i just assumed i needed new plugs (99000 miles) ive been running chevron techron in the fuel to hopefully have no problems with them. its a 05 f150 5.4.
i tried searching maybe i didnt use the right words.
thanks for any help in advance and yes i will take it to a buddy with a scan tool when i get a chance which will hopefully be by next weekend busy as heck with work.

oh and also my battery is very weak barely starts in the morning and evening but again hard to go to the parts store when you work 6 to 8 and the parts stores are open 8 to 530

 

got off work early today and made it to my buddys house hooked scan tool up and she was missing but cannot tell what cylinder it is checked the coil packs and the injectors and nothing seems to be out of specks so im leaning towards the plugs are causing the issue. its weird the truck seems to be running fine now minus a very slight rough idle almost unnoticable. i am gunna attempt the plug change, any words of advice for me?
also talked to a mechanic today about plugs and he said to try the e3's instead of the motorcraft do to the slight price difference.

 

Just do the motorcraft sp-515. They were specifically designed for that motor by ford. So just use em. Remember to use anti-seize

 

well did the plugs, motorcraft sp 515s and still seem to have the same problem. only 4 of the plugs broke, anyone have any ideas?

 

Only in a Triton would four broken plugs be a relief.

 

yeah it was the first four broke, i did the drivers side first. i was so mad then did the rear passenger side one and it came out hard the whole way but was all in one piece along with the last three. it seemed that the ones that broke unscrewed much easier then the ones that didnt.

 

so i was informed by a local mechanic that when removing plugs out of the 5.4 using the lisle tool you can very easily bend a valve. I find this hard to beleive but i have not seen the underside of the head to see the position of the valves, and also how could you do that? from my understanding the lisle tool it doesnt push anything past where the plug would normally be. anyone have any ideas on this or run into bending a valve when removing the broken plugs?

 

Never heard of bending a valve using the removal tool. But check all COP's and make sure there tight with the plugs. They are touchy and chances are if none are loose you have a bad one in the mix. One other thing is the FPDM, i believe thats right, its above your spare on the crossmember if it has an aluminum back and badly corroded its probably time for that to see its way out also.

 

Hard starts, miss firing at particular RPMs and no codes. You may want to check the Fuel delivery module as refernced by ellis4pa. Our trucks change fuel pumps are modulated depending on speed, etc. and when this module goes it can act weird, things like having to open gas cap ot get truck started, etc.

 

well got it all figured out plugs did fix the miss issue. the reason it continued to run bad after plug change is my fault, i bent a pin on one of the computer connectors when i reinstalled it while doing plugs.