2001 f150 5.4 misfire problem

Working on a misfire problem with this super crew.3 weeks ago had a miss replaced the coil on one after pulling the connector off of each to determine which cylinder was miss firing.Fixed it i thought? ran perfect now miss firing again!Pulled all plugs replaced them scanned it came up with a tcs code could a code from the tcs cause a misfire?also came up with miss fire codes for #3 and #8 any ford techs out there with a solution?could more coils be bad?read on all data that to many people are assuming that the coils are bad when they are not.Any ideas from some good techs would be helpful.Thanks

Any fluid getting it the plug wells? I replaced the boots on the cops when I replaced plugs. Still have a weird miss but only in park/neutral while reving the engine. . Think it might be egr related but will not bother with it until it happens in gear.

Just my two cent.

I have the 01 5.4 have had miss problems the last fix was plugs. The other night had real bad miss put heet water remover in tank by god it stopped the miss. Coincidence or moisture in the tank ill never know

I have the 01 5.4 have had miss problems the last fix was plugs. The other night had real bad miss put heet water remover in tank by god it stopped the miss. Coincidence or moisture in the tank ill never knowWell drove it home from work 12 miles still missing and around town for an hour still missing parked it overnight outside it was around 20 here in iowa last night.got in it started to work got about 8 miles and it started running perfect and still is as of today again after replacing the one coil weeks ago.Wonder if when you put the coil plug wires back on if they are completely going on the plug?they only go down so far in that long hole i will add some heet anyway anything to stop the old problem dont want to do the plug thing again.Thanks guys

Well drove it home from work 12 miles still missing and around town for an hour still missing parked it overnight outside it was around 20 here in iowa last night.got in it started to work got about 8 miles and it started running perfect and still is as of today again after replacing the one coil weeks ago.Wonder if when you put the coil plug wires back on if they are completely going on the plug?they only go down so far in that long hole i will add some heet anyway anything to stop the old problem dont want to do the plug thing again.Thanks guysWell so far the ford is running smoothly added a coulpe pints of napa gas stuff but i think with the oil leaking(not this one)from where ever into the the plug holes causes alot of the problem Poor design ford lovers.

i had a simalar prob. i had a misfire on #2. and an engine light. i unplugged the coil wire and plugged it back in. then i unhooked the battery for 24 hours which resets the computer. after that 24 hours i hooked the battery back up and haven't had the prob since. i have put 10k mile on it since i did that.

I have a 2001 f150 with a miss in the engine. I have replaced the plugs and the fuel filter. The miss happens at low rpm's in O/D or when I am stopped but still in drive or reverse. I do not have an engine light coming on so I can't scan for a bad coil. Sound familiar to anyone?

Also, I noticed that the drivers side valve cover has a brass nipple toward the firewall on the top. Is there supposed to be a vacuum line hooked up to it?

I always check the wires with an in line checker light at nighttime to make sure the spark is perfect to the plugs. I sandblast the sparkplugs or use new ones.

Also low/no fuel pressure, cloged fuel injectors, or air filters will effect your firing.

Firing order must be correct!

Any fluid getting it the plug wells? I replaced the boots on the cops when I replaced plugs. Still have a weird miss but only in park/neutral while reving the engine. . Think it might be egr related but will not bother with it until it happens in gear.

Just my two cent.


Yes, if you find OIL on the spark plugs *NOT CARBON*, your valve cover boot seals or your valve stem seals are leaking. I hear worst case scenario is your piston rings are gone and its leaking from the oil pan up.

I have a 2001 f150 with a miss in the engine. I have replaced the plugs and the fuel filter. The miss happens at low rpm's in O/D or when I am stopped but still in drive or reverse. I do not have an engine light coming on so I can't scan for a bad coil. Sound familiar to anyone?

Also, I noticed that the drivers side valve cover has a brass nipple toward the firewall on the top. Is there supposed to be a vacuum line hooked up to it?

I have the same problem. I just got done replacing the injectors, coils, and installed brand new plugs. It seemed to run fine yesterday when I got done, but today I have the same problem. What could it be? It seems like it runs worse when it is damp out or raining. Truck has 126k miles on it.

Hopefully someone can figure this out for me??

I have the same problem. I just got done replacing the injectors, coils, and installed brand new plugs. It seemed to run fine yesterday when I got done, but today I have the same problem. What could it be? It seems like it runs worse when it is damp out or raining. Truck has 126k miles on it.

Hopefully someone can figure this out for me??

Sometimes a motor will have heavy carbon buildup in the intake area. The carbon will get stuck on the valves and the spark plugs. Take a couple spark plugs out to make sure they are still clean. If too much carbon gets on your new plugs they will foul out and not spark. I had this problem with a couple older cars.

I had to use some carb cleaner and some throttle body spray over a couple days to get it really clean.

Also, check for frayed plug wires. One time I had a ford mustang that had a plug wire touching the block that burnt up. Then the wire starting sparking the block which shut off the engine.

Im having similar problems with my 2002 F150 4.6 triton misfiring.It misfired from the beginning.(In park and low rpm under load),so I replaced plugs still ran the same.Had truck put on scanner at autozone, scanner detected misfires 0n cyl. 1 and 3,so than I replaced the coils on cyls 1+3,brought back to azone scanner detected misfire on cyl.3 only.I tried the "disconnect battery to resetcom" did nothing but clear chk eng light.checked plug on cyl 3 and found NO oil but smelled like gas.Can anyone help?

I have 2001 F150 4.2L it seems to misfire at low RPM's, worse in damp or when engine is cold. Just giving a little throttle helps, more gas gives more of a shudder/misfire. I changed the DPFE, plugs and wires, put injector cleaner in. Changing the plugs helped a bit for a short while.

I bought a 2001 ford f150 5.4 it has 93000 on it, runs great when im sitting in drive
it will misfire just every once and a while just seeing if any body know how to fix it

it has not had a check engine light on

thanks

Hello F-150 Fans.... I had the very bad shudder and miss problem with cylinder #4 on my wifes 99 f150 4.6, I replaced the plugs. Didn't help. I swapped the coils packs, that didn't help. Problem stayed on that cylinder. I went to bed and woke up in the middle of the night with the answer. Next evening, I swapped the injectors. I put #1 in #4 and visa-versa... Problem moved to #1 cylinder... 62 bucks and runs like a charm.... If you have multiple missfires, I would think plugs or bad gas.... I hope this helps....

could be your spark plug wires Malfunctioning/shorted, boot's not seated properly or weak spark connection

could still be the spark plugs...i had the same issue, had a cheaper autolite sparkplug put in and it missfires within 1100 miles on the brand new plug. id replace them with motorcraft sparkplugs. it isnt too common for it to be a coil, with mine it was all spark plugs and boots. mine did it from 141,000-157,000 miles...the last 14,000 miles i havent had any issues with the motorcraft plugs