Help with ‘04 5.4l 3v Ford Triton misfire

[CrzTyler]

Further tests didn’t reveal any injector issues unless I didn’t understand the messages.

Another question, can one cylinder misfiring significantly cause the next cylinder in the firing order or any other “downstream “ to misfire ?

Yes cylinder misfires severe enough can cause adjacent misfire reading on either side of it.

You could also look at your trouble cylinders, write it down and swap coils with known good coils just to be sure, just keep track of where the “bad” ones are going.
Gets a little more difficult to remember when you’re swapping multiple coils bank to bank.

Could be a stuck valve, it would still have good compression since the valve is never open so a compression test wouldn’t really throw a red flag.

I had an 03 the other week had random misfires, did valve covers to stop oil intrusion into spark plug holes, new plugs and coils, still skipping.

Turned out they had a save a thread insert already in a hole that was letting air escape under compression, replaced insert and g2g.

Does yours have the cam phasers or no phasers?
Also an overlooked component is the pcm, I’ve had to circuit test a few very rarely you’ll get a computer module not sending proper signals and causing intermittent misfires.

 

[Howard Shadix]

Yes cylinder misfires severe enough can cause adjacent misfire reading on either side of it.

You could also look at your trouble cylinders, write it down and swap coils with known good coils just to be sure, just keep track of where the “bad” ones are going.
Gets a little more difficult to remember when you’re swapping multiple coils bank to bank.

Could be a stuck valve, it would still have good compression since the valve is never open so a compression test wouldn’t really throw a red flag.

I had an 03 the other week had random misfires, did valve covers to stop oil intrusion into spark plug holes, new plugs and coils, still skipping.

Turned out they had a save a thread insert already in a hole that was letting air escape under compression, replaced insert and g2g.

Does yours have the cam phasers or no phasers?
Also an overlooked component is the pcm, I’ve had to circuit test a few very rarely you’ll get a computer module not sending proper signals and causing intermittent misfires.

Since the initial DTC was cylinder 6 and I made repair befor I got Forscan the mode 6 data doesn't show 6 misfiring anymore but cylinder 7 is the main culprit I'm still leaning to new coils/plugs all around, expensive, but I don't have the time to chase them all around and if I have to get a new motor in the end, at least I can transfer some of these parts onto it. Another option is order all the parts, start adding them till it goes away and return the ones I don't use.

Ruger34 done gon and said it out loud givin me bad ju ju!

I appreciate everyone's help.....except Ruger34, he's got me worried.

 

[Howard Shadix]

Since the initial DTC was cylinder 6 and I made repair befor I got Forscan the mode 6 data doesn't show 6 misfiring anymore but cylinder 7 is the main culprit I'm still leaning to new coils/plugs all around, expensive, but I don't have the time to chase them all around and if I have to get a new motor in the end, at least I can transfer some of these parts onto it. Another option is order all the parts, start adding them till it goes away and return the ones I don't use.

Ruger34 done gon and said it out loud givin me bad ju ju!

I appreciate everyone's help.....except Ruger34, he's got me worried.

Forgot, yes mine does have the cam phasers, replaced the whole kit and kaboodle about 6mo ago

 

[Ken Ford]

There is not causation/correlation to the timing and crank assembly failure.
No more than, "I put fuel in and threw a rod 50 miles later". Neither one caused by or was a predicture for failure.

 

[Gunny Jake]

Turn Off Traction Control and Try It Out. I have an '03 that was intermittently misfiring. With traction control turned off it runs right.

 

[Howard Shadix]

Turn Off Traction Control and Try It Out. I have an '03 that was intermittently misfiring. With traction control turned off it runs right.

No traction control that I'm aware of on mine, just OD on/Off. But thanks!

 

[CrzTyler]

Yeah a good place to start is coil packs, the newer engines have great coil packs and it’s almost unheard of to replace on a coyote or eco boost. Unfortunately the tritons are notorious, might want to check plug holes for oil as well.
Especially if it’s multiple on one bank.
Kind of hard need a mirror and a light or bore scope.

But if you ever have the engine out or front cover off again, you can buy a lockout kit for the phasers.
You unbolt the plate on the back of the phaser, install a billet aluminum block to mechanically lock the phaser, then install the pre loaded tune to the permanently lock the software in the advanced setting so to speak so no more broken guides or timing chain stretch.
Man do they run smooth after the lockout kit.

Turn Off Traction Control and Try It Out. I have an '03 that was intermittently misfiring. With traction control turned off it runs right.

I’ve seen this as well, some models with o/d have the same issue, I believe it’s related to a chaffed harness causing a short circuit if I remember correctly.
Worth a shot.

 

[Howard Shadix]

Waiting on parts, I always use cheapest shipping so wait is longer. Not showing injector issues or anything on Forscan so I’m going with plugs and coils.

 

[Howard Shadix]

Well I have an update. Parts came in today but I had some shingles blow off in the storm. So I put in an order at big Orange for the roofing stuff. (Thanks Threejays! you’d think I’d be more appreciative for the trade skills huh?)

I thought I could get all the new coils and plugs in and then drive to pick up my order…so that’s what I did.

Only 18 miles but not a single misfire. Tried to duplicate the load /gear/throttle status and not a hiccup. Still really only preliminary results but I’m hopeful. Normally it would’ve had some misfires in those conditions.

Thank you all and if it starts back I’ll let ya know.

Oh yeah, Threejays, I finished fixing the roof afterwards and it’s good till next storm. South side starting to look pretty rough, know any roofers???

 

[CrzTyler]

Congrats