I've got an 08 f-250 with the V10 and I think the actuator that controls the intake runners is bad but I haven't found any info on how to test it. Does anyone have any info on this? I bought a haynes manual but it doesn't even mention it.
I've manually moved it back and forth and it's hard to tell a difference in either position.

Thanks!

 

I can't help much but how do you know it's not working properly?

 

I don't know for sure but in attempting to track down this misfire issue, I found another thread on a different manufacturer that had identical symptoms and their solution was this actuator.
I've got multiple misfires but worst on 4 & 9. Not hard misfires unless I punch it. All plugs and coils are new. Codes are only for the misfires. I've smoked it so I know there's not a vacuum leak anywhere. And I've ran a ton of seafoam through the fuel. Fuel filter is new as well. I've even rotated fuel injectors and coils to make sure they weren't bad.
The actuator and the intake are like $500 each so I'd rather keep troubleshooting than just blindly replacing parts

 

I have been on this forum for many years and this would be the first time I have heard of this being the cause of misfires.

 

Did the V10's come in 3V too? As long as I've been here I never paid any attention to that fact. And do these DTC's occur and seem to self-correct? If you clear the DTC's are they triggered almost immediately after starting the engine again or only when under a load? If any of this following doesn't apply to a 3V motor please just disregard altogether.

Anyway.......I have or had a consistent misfire DTC on my #6 of a 2005 5.4 2V V8 that had me replacing the COP with a new Motorcraft DG-508---three different times over 20K miles and 11 months. I replaced the COP wiring harness connector (NAPA EC-259, locking tab broken) too but the DTC would still return. New boots, Motorcraft plugs, properly installed and torqued. This had me more than a bit perplexed until talking with a very experienced former dealership mechanic with a ton of qualified training.

Before that conversation I thought it might be the PCM or the wiring harnesses from the PCM to the Bank 2 injectors/COP's. (This particular vehicle's model year has a suspect PCM as it was first year of the CAN-bus network--cheaply made PCM PCB's.)

He'd seen this before, suggested it most likely was a fitment issue between the terminal pins of the COP and whatever wiring harness connector I was using. He did mention the small rectangular seal inside the wiring harness connector being important helping maintain contact--they can sometimes "disappear" when the connector is removed from the COP. (I'm sure most of us would know to check and replace that seal if it was missing.)

So long story short double and triple check the affected cylinders for intermittent contact.

Also FWIW if you want an authentic Work Shop Manual head to eBay for gently used manuals from Ford---a few in printed form should be available. While the Haynes and Chilton are great for hoit-to's on renewing your Coconut-scented air freshener or a door stop they're simply not that helpful in situations like this.

 

Yes, this is a 3V. I've tried switching coils around even switching a couple injectors with no luck. The DTCs are almost immediate and consistent. Cyl 4 is the worst, then 9, then 2 and 8. I also get code 300 for multiple misfires, even when things were just reset and counts are low. I have a halfway decent scanner that gives specific number of misfires per cylinder and the only cylinder that seems to be completely trouble free is 6. So maybe I'll switch 4 with 6 and see if that changes anything. I cleared it yesterday and went for a 10 minute drive and 304 and 300 popped almost immediately. Misfire count on cyl 4 by the end of the drive was 494. All other cylinders (except 6) had between 5-30.
All plugs and coils are new as of about 10k miles ago when I bought the truck. The plugs are motorcraft, the coils are not. Does off brand make that much of a difference? I've not had this particular brand before but I've used Advance autos brand on my 99 250 LD before without issue.
thats a good point about the seals in the connector so I will check those as well, thanks!
i have an appointment for next week at a local shop that I trust but I'd rather figure it out on my own.

 

There have been issues with using non-motorcraft parts especially the coils.

 

Did these problems exist when you first bought the truck or recently develop? Did they pop up before or after replacing the plugs and COP's? Any other work done that might affect the ignition system?

Which Motorcraft equal part number did you use? I'm not familiar with the 3V Modular Motors but it seems there is a DG-511 w/black coil boots and DG-521's w/brown boots? That might play into this as well

The more you describe these misfires I'm leaning towards an electrical issue with or from the PCM to the COP's, quite possibly one of the larger multi-circuit connectors that feed each side of the engine. It wouldn't be uncommon if part of the wiring harnesses have been dislodged or slightly damaged while under the hood. Double check your work just to make sure---a magnifying glass and bright working light will be helpful.

Yep and when I first bought a set of cheaper COP's---Granatelli brand FWIW---quite quickly one failed. Soon after another failed and since they were still under warranty swapped 'em all out for the orginals. That was back in 2004 and the OEM's installed 2000 are still alive, 6 of them anyway, over 292K miles so far.

Motorcraft COP's are available everywhere online but buy from a reputable seller like Amazon---and watch this video about counterfeit COP's with Motorcraft branding:


Something like this can aggravate the hell outta a guy---or gal for that matter. I hope this is an easy fix, hope you kept the receipt for those COP's?

 

When I first bought the truck I had a ton of misfires too but I figured that was due to the original plugs and original coils. Original plugs were a pain! 8 of the 10 broke in some way. So I swapped out every and it ran great for like 5k miles. Then the misfires started. It was only on a cold start at first then it would clear up after a few minutes. Then they stayed. There's still no hard misfires. I swapped the coils yesterday from 4 (the worst) to 6 (no misfires) and the misfires stayed on 4 as the worst. I used SKP SKIC003 from rock Auto and they claim the OE equivalent of 3L3Z12029BA which is black boot and black boot is what I pulled out originally.
I also ohmed out the injectors yesterday and all are sitting in the low 13 range. I have not done any other work to the ignition system or wiring that could affect it. I did pull the pcm out last weekend just to make sure there were no obvious signs of water damage or anything and it looks clean.
it had 240k on it when I got it last summer so it's been used. Its a northern truck so there's rust.
A friend suggested the pcm as well. Any way to test that specifically?

 

Do you have a stable/good voltage source? Meaning, is the alternator and battery OK? When idling, turn on the headlights, do they flicker?

What plugs did you use as replacements?

 

Funny you should ask that. The headlights are... Sensitive? They don't flicker but they do occasionally dim. When they dim, I can reach in and move them just slightly and they go back to full strength. Most of the time, they go back to full strength on their own, pretty quickly. Battery is a duralast gold and is like 2 months old. It didn't need a new battery but my 11 f250 did so I took the one out of this one I'm having trouble with and bought a new one a few days later when I had time. I own a landscape company and this truck I'm having trouble with is the backup truck. I've not had problems with the battery or alternator before or after the battery replacement.

Plugs are motorcraft PZK14F purchased from advance auto parts

 

Okay so I'm guessing since you're not triggering any injector codes, only those relating to ignition component issues that's not your issue. PCM's can and have developed internal issues where something is possibly beginning to fail, a visual inspection of the case won't usually be helpful. I supposed the PCM could be sent off to one of the repair outfits who specialize in that which might not be a bad idea at this point. It would seem new plugs and COP's didn't improve anything.

The wiring between the PCM and COP's might have developed corrosion on the wiring harness connector's terminals giving you intermittent or complete loss of contact to the COP's. This would require visually inspecting them, perhaps cleaning both male and female sides to assure full contact.

I don't know whether the black boots or brown boots were originally spec'd for your year and build date, someone here can clear that up. Regardless what existed on the truck when you bought it I'd go with the knowledgeable guy's advice on which would be correct.


H/L-wise what are you reaching in and moving----the main switch or the lamps and wiring under the hood? Have you tested the alternator's voltage output with a DMM or dedicated system tester? I also have H/L issues where they both don't come on until I jiggle the wiring harness for the main switch. That doesn't seem to be your problem here.

I'll suggest you're all over the map buying from this source or that and using a cheaper "equivalent" part when authentic Motorcraft stuff is available in so many places these days. Despite claims of being same as or equal to OEM-level quality most simply aren't. Having read too many posts where misfires occur and new parts often times its the brand of the part that makes the difference. For that reason alone I no longer use anything other than genuine MC stuff.. Denso is said to be the actual manufacturer of Motorcraft and OEM COP's and are highly regarded here. Same with NAPA's better line of COP's---just ideas mind you.

Hope somethng shakes out for you---I hate these kinds of annoying and time-consuming problems!

 

I’m having misfires so after replacing my spark plugs and coils .

 

It was the plugs. I pulled them a found them gapped seriously won't on the 2 that were giving me misfires. So I replaced them and it fixed my misfires