Who has a 7.3 and experienced the "misfire" plug wire concern or not please leave feedback

Issue or no issue

  • Yes

    Votes: 19 21.6%
  • No

    Votes: 69 78.4%

  • Total voters
    88
I can only speak for my situation, but I'm satisfied with the troubleshooting process to prove it was the wire. See the steps in the dealer invoice.

Long and short of it is, if you get a misfire on cylinder 2, clear codes and swap spark plug wire from cylinder 2 to cylinder 1 and the misfire condition follows to cylinder 1 then it's not either cylinder or either spark plug it has to be the wire.
No argument from me here, makes sense to me.

I think where he was headed was more along the lines of which came 1st, chicken or the egg?

I don’t think there’s any doubt the wires are a problem, but from what I’ve read on this forum it doesn’t sound like there’s been a 110% determination as to what is causing that - is it simply inferior/faulty wires, or is there more to the story?

I can’t speak from personal experience as mine is a 6.7, just going off many other comments I’ve read from others here.
 
No argument from me here, makes sense to me.

I think where he was headed was more along the lines of which came 1st, chicken or the egg?

I don’t think there’s any doubt the wires are a problem, but from what I’ve read on this forum it doesn’t sound like there’s been a 110% determination as to what is causing that - is it simply inferior/faulty wires, or is there more to the story?

I can’t speak from personal experience as mine is a 6.7, just going off many other comments I’ve read from others here.
Maybe I can summon @Bluezilla for an experiment one day and we check out his plugs out with my snap on IR camera?
 
No doubt the in my mind the plug wires are a symptom and not the issue. As stated, original OEM, replacement OEM and aftermarket plug wires all failed. There appears to be an correlation between high rpms and failure at the connector from the wire to the plug. My opinion is the ignition coils are pushing higher amps and melting the wires from the inside out.
ED2E7FFB-CC0A-421B-AAE6-3BE7353D0667.jpeg

From cylinder 1 to 8 every plug wire showed signs of scorching from the inside out.
 
No doubt the in my mind the plug wires are a symptom and not the issue. As stated, original OEM, replacement OEM and aftermarket plug wires all failed. There appears to be an correlation between high rpms and failure at the connector from the wire to the plug. My opinion is the ignition coils are pushing higher amps and melting the wires from the inside out.View attachment 33959
From cylinder 1 to 8 every plug wire showed signs of scorching from the inside out.

Which aftermarket wires are those? This thread got me a little spooked as Im going on a long camping trip to the beach next week so I ordered a spare plug wire off of ebay, only 15 bucks and its the oem motorhome C wire so gonna look to see if there is a diff.
 
I've read on an RV site that the lower wire in this pic are the latest wires. They are the wires that came on my 7.3 built in August of 21.
There is more space around the wire, it is wider at the bend, and there is a spring around the boot to give space and air flow I'm guessing. The lower wire in the pic is the new one, (not my pic), compared with the old wire, (top).
LC3Z-12286-C (WR6167)
fullsizeoutput_94f.jpeg
 
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I have documented my issues with the 7.3L on other post but will recap here.
I had a 2020 F350 Lariat Sport with a 12/19/2019 build date that I purchased new in April 2020. It had a rough cold start/cold idle early on. Picked up my Cirrus 820 truck camper in May 2020 and did many trips around Colorado, Wyoming and Utah throughout 2020. Decided in early 2021 to trade truck camper for a Black Series HQ19 that we picked up in south AZ and drove back to Denver without truck issues, I had about 28k miles on the truck at that time. In March, my Dad had a stroke so we packed up in a blizzard and hauled ass cross country in 3 days to NC pulling the camper. Arriving in NC after a hard push through the NC mountains, I had a severe delayed start after unhooking the trailer before heading to the hospital. Next morning had another delayed start so I stopped by my buddies Ford dealership in Raleigh NC. They ran diagnostics but found no codes. I had them order me the plug wires because I had seen the TFLtruck video and I threw them under the back seat. We made a return a week later via the southern route down to Pensacola before returning to CO with occasional delayed starts but still no lights or limp mode. Not much towing in April as we were back in NC. In May, I installed Massive wires which helped with the delayed start for a couple of days but it returned once we did a drive over an hour. Started a move to Utah in early June and when hauling a UHAUL trailer smelled burning at the top of grade south of Laramie. Stopped at dealership in Laramie and no codes still, truck had cooled by the time he ran diagnostics. Several trips over the next week back and forth between CO and UT with delayed starts and smelling burning rubber. Last trip in mid June was pulling the camper west on I70 out of Denver, had misfires at the top of the hill in Evergreen with check engine lights and limp mode. Stopped in Idaho Springs and let it cool down (engine temps never exceeded 218F) and called Silverthorne Ford. Drove the Ike with more misfires and check engine light and limped into Silverthorne where they ran diagnostics. Lost cylinder 5 & 6 wires with no stock wires available. Luckily I had the two in my truck from March. Replaced wires camped at Steamboat and proceeded the next day. More misfires west of Craig and Vernal but I didn’t have more wires. I ordered a set of OEM A wires and replaced all 8 the next week. Every Massive wire had different levels of melting on the boot. The OEM lasted a couple of days before delayed start returned. Finally got an appointment for service first week of July. Cylinder 1 & 4 wire was toast they replaced both wires. Dealer was going to order new wires, plugs and coil packs but it was going to be August before the coil packs would be in. I got a check engine light leaving the dealership and returned, cylinder 1 had misfired on the on ramp. Limped around for a couple of weeks. Massive sent replacement wires that are sitting in my garage still unopened. I ordered a set of C wires to check them out (returned never installed). They are different from the non motorhome A wires. Truck boiled out the battery in July a week before we were to go to Yellowstone with my 90 year old father in law. Went to the dealership the next day and traded it in for a 2021 F350 Lariat Sport diesel. The 7.3L had 34k miles on it. Like I said in other post, I was probably an exception and most 7.3L will not have problems but I could no longer trust that vehicle and won’t own a truck that I can’t be sure will start and stay running in the middle of nowhere. Happy with the diesel, 6k since the last week of July. No issues towing on a trip to Yellowstone and to the Oregon coast and a couple of off-road excursions with and without the camper. Heading to Arizona next week, camper in tow.
This is great information, but hard to read without a couple of paragraphs or line breaks between thoughts.

Either you are a very fast typist, or it was copied from somewhere else without the line breaks. (y)
 
I've read on an RV site that the lower wire in this pic are the latest wires. They are the wires that came on my 7.3 built in August of 21.
There is more space around the wire, it is wider at the bend, and there is a spring around the boot to give space and air flow I'm guessing. The lower wire in the pic is the new one, (not my pic), compared with the old wire, (top).
LC3Z-12286-C (WR6167) View attachment 33977
My 22 wires look different then either of these wires
 
I've read on an RV site that the lower wire in this pic are the latest wires. They are the wires that came on my 7.3 built in August of 21.
There is more space around the wire, it is wider at the bend, and there is a spring around the boot to give space and air flow I'm guessing. The lower wire in the pic is the new one, (not my pic), compared with the old wire, (top).
LC3Z-12286-C (WR6167) View attachment 33977
The strange thing is I've called multiple dealers and not a single one can look up and see the -C wire in their system. It doesn't seem to exist in "Ford Universe."
 
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I'm sure there is a DFMEA out there with this failure mode on it.

The real question is, are the wires failing at temperatures they should survive, or are the wires reaching temperatures higher then they were designed to withstand?

If it is the former, I would expect the Massive wires to work well, but these are failing also.

If it is the latter, what is the source of the heat, and how can you mitigate it?
 
Build date is 8/24/20, delivery date 10/8/20. has 4200 miles no problems yet. BUT at 3500 miles I bought a set of fire core wires for it and kept the OEMs for spares.
Delivery 10/8/20 and only 4200 miles. Man get out there and drive that baby.
I have had mine for only 4 months and it has 8000 miles on it. I use every excuse I can to drive it. I put a Ham radio in it just to have an excuse to sit in it in the driveway.

BTW, no misfire problem yet.
 
Which aftermarket wires are those? This thread got me a little spooked as Im going on a long camping trip to the beach next week so I ordered a spare plug wire off of ebay, only 15 bucks and its the oem motorhome C wire so gonna look to see if there is a diff.
Massive wires with the heat shield. The C plug wire looks like an improvement over the A plug wire.

Bring a diagnostic tool to check which cylinder. Passenger front to back cylinder 1-4, driver front to back 5-8.
 
This is great information, but hard to read without a couple of paragraphs or line breaks between thoughts.

Either you are a very fast typist, or it was copied from somewhere else without the line breaks. (y)
Sorry about grammar, it was posted at 4:30 am on the toilet.

I thought it was more important to share my experience on this thread.🧐
 
I'm sure there is a DFMEA out there with this failure mode on it.

The real question is, are the wires failing at temperatures they should survive, or are the wires reaching temperatures higher then they were designed to withstand?

If it is the former, I would expect the Massive wires to work well, but these are failing also.

If it is the latter, what is the source of the heat, and how can you mitigate it?
Never exceeded 218F engine temp.
 
I'm curious what your wires look like. Here's my wires. My truck was built in August


View attachment 34067
Those are definitely different, I wonder if they are the mysterious B wires?🤨 Note the air gap at the top of the boot. The A wire is sealed in @Trapper photo above but the boot does not look like the C wire. Maybe Ford figured there’s too much heat generated inside the boot and needs to vent it.
 
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