Misfire codes (P0308, P0306, P0300) on a stock gen2 coyote with 60k miles

[BluePonyGT]

Nice!

Did the coils fix the cels?

Got a part number for the coils? Thanks!

M-12029-M50E

…for the ford performance coil packs. I got them from summit racing to save a few bucks. Like I said above it didn’t solve my iss but did help to eliminate the P0300 codes I was getting.

I’m using the same motorcraft plugs as stock:

CYFS12F1

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[BluePonyGT]

After doing a little bit of research on the battery voltage, it's seems like the mustang's have a smart charging system that only charges the battery under the right conditions. And how did the new parts go? Is it still misfiring? A little update from me, is I took my mustang to the Ford Performance service shop today so I am waiting to hear from them on what could possibly be causing the Mustang to misfire

yep I think I was chasing a red herring there. Thanks for the info.

 

[Cobra Jet]

Ok, here's a big update:

After installing the ford performance coils and plugs, and during the show last weekend yielded zero codes - until the trip home. It's been nothing but P0306 and P0308 codes since. Probably one every other day just like before.

I did inspect my wiring harness. That was actually a really good idea to check for rodent damage. Since the pandemic the Seattle area has had its share of rat outbreaks. They got into my garage over the winter and made a hell of a mess. They also got up into my engine compartment (probably for warmth) and made a mess there too which I spent several angry hours cleaning up and declaring scorched earth against any rats since then. After putting out some traps, and putting a sound/light emitter under the hood all of that nonsense stopped back in early February. This misfire thing started in July, but it could still be related. I looked over all of the coil connectors, the harness back to the loom, the injector connectors, and back, and in the back of the motor and I don't see any damage at all.

So all that being said I decide to go ahead and pull the trigger on the PP3 GT350 intake, throttle body and cold air box swap starting yesterday. I got the original intake off the engine and after pulling the fuel rail off and flipping it over I have the exact same problem as you see all over the web:

https://www.mustang6g.com/forums/threads/broken-imrc-shaft-p0308-p0300.100363/

The valve actuates just fine on the passenger side, but on the driver's side it sticks about half way closed and hardly actuates at all. I took a video of it:

I finished the swap and reprogrammed the PCU. It performs way better and I love the improved shifting. I can tell it responds a hell of a lot better. I’ll see if I get any codes.

Well, that’s really good to hear you found the issue and fixed it. Among other things, I mentioned IMRCs in Post 2…. LOL… as I said, that IMRC design and system is garbage, Ford Engineers need to come up with a better, more robust design that won’t fail as easily…

 

[BluePonyGT]

Well, that’s really good to hear you found the issue and fixed it. Among other things, I mentioned IMRCs in Post 2…. LOL… as I said, that IMRC design and system is garbage, Ford Engineers need to come up with a better, more robust design that won’t fail as easily…

Yeah I suspected that was the case since I mentioned it in the OP if we're being specific, but didn't want to pull the intake right away to find out I was correct then not have a replacement when I did.

So that gave me time to be systematic. I recorded when I had codes, what they were, what driving mode was I in, etc. The result is I learned a lot about the system, which is good.

I will say it's tempting to perform an IMRC delete. I've been looking at that.

 

[Cobra Jet]

Yeah I suspected that was the case since I mentioned it in the OP if we're being specific, but didn't want to pull the intake right away to find out I was correct then not have a replacement when I did.

So that gave me time to be systematic. I recorded when I had codes, what they were, what driving mode was I in, etc. The result is I learned a lot about the system, which is good.

I will say it's tempting to perform an IMRC delete. I've been looking at that.

Yea, the IMRC deletes have been a popular option since the 1996 DOHC SVT Cobra days - that's when those first hit the market. I'm just really surprised Ford Engineers haven't been able to design better IMRC hardware that won't prematurely fail (in some cases).

Did you see the DIY IMRC shaft fix thread? If you haven't, see here if you wanted to tinker around with your old intake to attempt a fix.
https://www.mustang6g.com/forums/threads/our-first-dtc-p0308.160243/

 

[BluePonyGT]

Yea, the IMRC deletes have been a popular option since the 1996 DOHC SVT Cobra days - that's when those first hit the market. I'm just really surprised Ford Engineers haven't been able to design better IMRC hardware that won't prematurely fail (in some cases).

Did you see the DIY IMRC shaft fix thread? If you haven't, see here if you wanted to tinker around with your old intake to attempt a fix.
https://www.mustang6g.com/forums/threads/our-first-dtc-p0308.160243/

Thank you! Much obliged. Fixing the old one regardless is a good idea if I decide to ever sell this car (never) or revert to stock (never) or just sell the intake (maybe).

NO CODES for a week. I'm still getting used to the power increase, and the shifting improvements. Wow. And it's nice having a programable interface now for the car. I was able to re-adjust the speedometer based on my tire size, which has been off since 2018.

 

[TexasRebel]

I've been throwing P0300 and P0301 codes on and off for a week now. I'm going to swap the coil to see if it moves, but I'm wondering if it isn't the same issue. I'm also getting more and more noise from the transmission tunnel. I think my clutch damper springs are toast. 142k on the original doesn't seem too bad though.

@Cobra Jet, What is the difference in the early and late coils on the 2016's? I can't find a thing about it. As I purchased on Feb 17, '16 I should have the early coils.

 

[Cory S]

What is the difference in the early and late coils on the 2016's?
[/QUOTE]
The change was made in late February of 2016. From what I’ve gathered, only the connector itself changed style because the wiring harness was outsourced from a different supplier.

 

[Cobra Jet]

I've been throwing P0300 and P0301 codes on and off for a week now. I'm going to swap the coil to see if it moves, but I'm wondering if it isn't the same issue. I'm also getting more and more noise from the transmission tunnel. I think my clutch damper springs are toast. 142k on the original doesn't seem too bad though.

@Cobra Jet, What is the difference in the early and late coils on the 2016's? I can't find a thing about it. As I purchased on Feb 17, '16 I should have the early coils.

The change was made in late February of 2016. From what I’ve gathered, only the connector itself changed style because the wiring harness was outsourced from a different supplier.

Thanks Cory - didn't see the thread update until now - but yes, as Cory said above, coils and the specs are same, just connector difference. So you would need model year specific coils.

 

[TexasRebel]

CEL came back on today. I'll pull the codes later, but I'm expecting the same.

From what I can tell, the only intake manifold available for these cars now is the 2018+ intake from Ford Performance that "requires a custom in calibration."
https://www.steeda.com/ford-performance-m-9424-m50c-s550-intake-manifold

Only, nowhere does it give any details as to how to come by this calibration. Nor does this say anything about working with the Performance Pack 2.

 

[gimmie11s]

I will say it's tempting to perform an IMRC delete. I've been looking at that.

Doubt be afraid to dump the IMRCs if the issue returns. I deleted when I installed turbos and I literally cannot tell any difference on the "low end" of the power curve. Seems exactly the same.

 

[TexasRebel]

Just the P0300 code this time. No specific cylinder.
I'm tempted to get the 18+ maifold and harness, but I can't find any specifics on the "custom calibration" that the part description says is required. Does anyone know where this would come from?

 

[TexasRebel]

The last two reads were P0301. I swapped my #1 and #2 coils. So far there hasn't been another code, and the stumble seems to be gone, for now.

 

[TexasRebel]

P0301 came back after swapping coils. Leads me to believe it's the injector.

Only... this morning the CEL went off by itself. Still thinking 140k miles might be enough on the original injectors.

 

[BluePonyGT]

P0301 came back after swapping coils. Leads me to believe it's the injector.

Only... this morning the CEL went off by itself. Still thinking 140k miles might be enough on the original injectors.

I had the same behavior across #6 and #8. No matter what coils I had on the plug the same ones kept throwing codes.

When I pulled the intake and found those broken flappers thats when I knew. It was always misfiring on just one side. Here's the post with the video in it:

https://www.mustang6g.com/forums/th...ote-with-60k-miles.177596/page-2#post-3607646

So you may be faced with the same choice I had. i decided to leap and get the Power Pack 3 upgrade and move to a GT350 intake. At the very least have an 18+ intake on hand before you pull your old one. If you end up installing the 18+ I believe you have to add a tune, but you'd use the Pro-Cal tool with the GT350 intake anyway. Either way you're most likely saying bye bye to the 15-17 intake. Mine is still broken, but in the box. Not sure if it's worth fixing, but I appreciate the fact that it can be.

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