Pulsing hesitant shuddering with slight acceleration

[WrenchinBrit]

Hey Guys 256k King Ranch HD tow 5.4 EL 2014

I'm getting a pulsing shudder if i feather the throttle to accelerate a little .. if i push harder it will downshift ok and run smooth .. I'm thinking injector? coil pack but fear trans issue ( have changed trans fluid and installed drain plug in pan for servicing the no service reqd trans)
I did try to goad it into behaving worse and managed to get a flashing CEL but it cleared


thoughts??

 

[bman440440]

coil pack... my 01 and 06 did the same thing... after a little wile it will get worse and worse and the cel will eventually stay on and tell you what coil pack(s) are the problem... but dont just replace the known bad one(s) just replace them all and save your self some headaches.

 

[WrenchinBrit]

just replace them all and save your self some headaches.

Thanks .. did you go for OEM or another particular brand?

 

[bman440440]

I went with accel only because I get a smoking deal on them threw a buddy... But normally I would go with OEM for them as well as plugs... I did not have any issues with them on the trucks with 60,000+ (2001) and 75,000+(2006) miles on coils when I sold the trucks.

 

[f150dave2002]

Spark plugs… sometimes one lasts 8,000 miles and some go 80,000+… with the platinum plugs, replace around 30,000 miles for best performance and be sure to stick with motorcraft plugs…

 

[WrenchinBrit]

Is there a resistance test that can be done to check the coil packs?

 

[Yupster Dog]

Is there a resistance test that can be done to check the coil packs?

How come a lot of people post "there was a CEL,MIL" but never post the codes? If you don't have a scanner Auto Zone or the like will test it for free. (at AZ they will print it out for free if you ask)

Get the codes first, If it was a misfire from a coil pack it will tell you what cylinder. You can then change the coil pack to another cylinder to see if the misfire moves.

Also coil packs are not maintenance items, i suggest you just replace the bad one.

 

[plumcolr]

I replaced 3 on my '06, one at a time, with motorcraft. After the third, I replaced all of them with the a package of 8 Accel packs. All 8 were cheaper than 2 of the motorcraft. Never had another issue. Later 5.4s apparently had the same issue.

 

[WrenchinBrit]

How come a lot of people post "there was a CEL,MIL" but never post the codes?

Hey Yupster
Thanks for posting .. unfortunately It won't throw a code.. iv'e tried to goad it into misbehaving but the worst it will do is flash the CEL .. my scanner wont find anything.. I'm not going to start replacing plugs or coils without narrowing it down hence the question about the resistance test on the coil pack. Even that will be a pain to start pulling them all as murphy's law it'll be the last one I test!

 

[WrenchinBrit]

The most I've done so far is to disconnect the coil leads and reconnect ( about a 5min job) that did help the severity and I thought i'd solved it but no, it started acting up shortly after..