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Posted

First post,

 

So for the last 6 months or so my truck has been throwing P050D cold start rough idle. I'm at 36k on the truck and it's a 2015. I brought the truck into the shop for diagnostics. They confirmed that for 1-2 minutes on a cold start condition, cylinder 4 misfires for about a minute or two then stops. They confirmed this multiple times. They verified no vacuum leaks, spark plugs and ignition coils checked out fine, bore scoped the cylinders and found no issues and no coolant leaks, they did a bunch of rebalancing and program checks, verified the related sensors, essentially everything with the exception of checking the injector itself because of the process and time it takes to do so. I know that these newer trucks send double pulses to the injectors during cold start until the truck warms up then it goes back to normal pulse frequency. I guess my question would be what is more likely? The fact that the injector is bad or that during the cold start the injector isn't receiving the pulses? I imagine that all the injectors would be wired in parallel to an extend and that all injectors would essential receive the same signal so I feel that the later is less likely and more than likely the injector itself. But the auto shop won't confirm that the injector is the actual source of the issue because they couldn't test it.

Posted

Welcome Salty504. Sorry your first post is about an issue, but that's usually why people join these forums - to troubleshoot what's going on. First, I wouldn't completely rule out coolant in your intake/cylinders. Just borescoping it might not show the coolant, they need to perform a dye test - it'll show even the smallest amounts of coolant (dye glows under black light). The coolant leaks can be the size of a needle and only allow very small drops, something the human eye can miss. Unfortunately, I went through this a couple months ago that resulted in both my cylinder heads getting replaced. The casting for the heads was not done properly in some cases and it results in coolant leaking into the cylinder and throwing the P050D code along with a rough cold start. As you pointed out though, it could just be a bad injector. I would first get the dye test to confirm there is or is not any coolant in your cylinder(s). If they don't get any glow then I would have them replace all injectors. You're doing all the same work to just replace one injector, might as well do them all while it's open.

 

If you're handy with tools and work on your vehicles I'll be posting a write-up on how to replace the injectors soon. Best of luck with your situation.

  • Like 1
Posted
10 minutes ago, midwestdenaliguy said:

Welcome Salty504. Sorry your first post is about an issue, but that's usually why people join these forums - to troubleshoot what's going on. First, I wouldn't completely rule out coolant in your intake/cylinders. Just borescoping it might not show the coolant, they need to perform a dye test - it'll show even the smallest amounts of coolant (dye glows under black light). The coolant leaks can be the size of a needle and only allow very small drops, something the human eye can miss. Unfortunately, I went through this a couple months ago that resulted in both my cylinder heads getting replaced. The casting for the heads was not done properly in some cases and it results in coolant leaking into the cylinder and throwing the P050D code along with a rough cold start. As you pointed out though, it could just be a bad injector. I would first get the dye test to confirm there is or is not any coolant in your cylinder(s). If they don't get any glow then I would have them replace all injectors. You're doing all the same work to just replace one injector, might as well do them all while it's open.

 

If you're handy with tools and work on your vehicles I'll be posting a write-up on how to replace the injectors soon. Best of luck with your situation.

Thank you for the detailed reply. They did do a dye test which came up negative. Honestly if you have a write up for these injectors that would be awesome. I've had no luck finding anything on how to replace anything 2014 and newer. I know it requires a bit more work than the older models with needing the hose sizing tool. Only thing that sucks is it's my only vehicle so it's more about having enough time to learn it, deal with first time time curve, and go through the process right.

Posted (edited)
31 minutes ago, Salty504 said:

Thank you for the detailed reply. They did do a dye test which came up negative. Honestly if you have a write up for these injectors that would be awesome. I've had no luck finding anything on how to replace anything 2014 and newer. I know it requires a bit more work than the older models with needing the hose sizing tool. Only thing that sucks is it's my only vehicle so it's more about having enough time to learn it, deal with first time time curve, and go through the process right.

I am in the same boat as you, truck is my only vehicle right now so I researched the crap out of how to do the injectors. I got it all done on a Saturday morning, so don't stress about not having your truck operational for long. Sold my Wrangler last year and definitely miss a second vehicle for when you want to mess around with one of them and not worry about not having something to drive.

Edited by midwestdenaliguy
Posted
2 hours ago, midwestdenaliguy said:

I am in the same boat as you, truck is my only vehicle right now so I researched the crap out of how to do the injectors. I got it all done on a Saturday morning, so don't stress about not having your truck operational for long. Sold my Wrangler last year and definitely miss a second vehicle for when you want to mess around with one of them and not worry about not having something to drive.

Well hey whenever you got the write up done I'd love to check it out and see if I can knock it out and save myself some labor costs.

Posted

I am thinking injector however. I just swap out plugs and wire for the cost to headaches value. Meter out the coil wires. But a performance shop would be able to log injector pulse in real time. As will as coils,misfire, O2 banks, and a million more. 

They could also override the ect idle tables just to see if it changes anything. 

Injectors are cheap but then 8 of them and 2 high pressure lines. 

Also when you are in there look at the intake ports on the heads for oil buildup and take a picture for you records. Also it is IMO a must to spray clean in the intake when it is of and let it dry. Same with TB and maf. Then when back together recalibrate the maf tables. 

Sorry it sounds like a lot but it is each just a few minutes simple stuff. 

Depending on miles on truck have shop look at the o2 sensors with the scanner down stream bank 1 and 2. On cold start there is a cat warm up.

Posted
11 minutes ago, 1SLOW1500 said:

I am thinking injector however. I just swap out plugs and wire for the cost to headaches value. Meter out the coil wires. But a performance shop would be able to log injector pulse in real time. As will as coils,misfire, O2 banks, and a million more. 

They could also override the ect idle tables just to see if it changes anything. 

Injectors are cheap but then 8 of them and 2 high pressure lines. 

Also when you are in there look at the intake ports on the heads for oil buildup and take a picture for you records. Also it is IMO a must to spray clean in the intake when it is of and let it dry. Same with TB and maf. Then when back together recalibrate the maf tables. 

Sorry it sounds like a lot but it is each just a few minutes simple stuff. 

Depending on miles on truck have shop look at the o2 sensors with the scanner down stream bank 1 and 2. On cold start there is a cat warm up.

1SLOW,

Thanks for the info. The shop I had it at did move the plugs and coils around and the misfire stayed on that cylinder. They also bore scoped the cylinders and didn't see anything worth noting. I thought they ohmed out the injectors but it may have just been the ignition coils. I've cleaned my MAF and have had a full fuel/intake systems flush and clean with no fix. 

Posted

Not to make you worry or go in circles but there are bulletins about the cleaning causing issues in the cats and O2 and the problems stated are misfires.
I would say at the data log of it so you can watch the injectors is a must. It will be night and day difference on the screen. You will see the issue.

Sent from my SM-N960U using Tapatalk

Posted
9 minutes ago, 1SLOW1500 said:

Not to make you worry or go in circles but there are bulletins about the cleaning causing issues in the cats and O2 and the problems stated are misfires.
I would say at the data log of it so you can watch the injectors is a must. It will be night and day difference on the screen. You will see the issue.

Sent from my SM-N960U using Tapatalk
 

Are you saying the fuel and intake cleaning causes the issue? Cause I had the code before I did any kind of flush. The shop was monitoring the injector while they were doing diagnostics.

Posted

How many mile are you at? We are seeing a tread on this. I am wondering about bad valve do to debris build up and burnt oil. 

Also did they clean with a solvent or blast the runers?

  • 4 years later...
Posted

I have this code as well. Weird thing is it only happens on the first start of the day after it sits all night. Once I drive it the rough idle goes away. Any thoughts?

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