What is AFT that you put in your fuel? Do you mean ATF? I usually run ashless two-cycle oil at about 3/4 oz per gallon in my fuel. Also, my truck is fully warmed up when it is giving me the issues.

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Really what I need is thoughts on how to diagnose which injector or injectors are not performing right and causing the shudder. Also, it sounds like I should have cleaned the injector pockets and maybe gotten a better torque wrench.

Yes ATF.

The fuel presure regulator maybe on the way out . 5C3Z 9C968 CA

It get riped the screen on the end .

Location behind turbo .

The ATF will clean up dirty parts .

Because of the sudden onset I am convinced it is injector related but don't know how to best diagnose which injector is giving me fits. Is it a sealing issue or a sticking issue? If so what is sticking? The spool valve? Wouldn't that show up on cold starts as well? It starts fine with no bucking/rough running.

It ended up being an injector connector that was disconnected. I must not have got it popped on good when I put it back together.

04 6.0 Missing HELP!!!! PLEASE
 

I have read all the posts on here, I just had all 8 injectors and all 8 glow plugs replaced. Truck had misfires in few cylinders. Now since having them all replaced the truck bucks or misses at highway speeds....I had mechanic ride with me and hook up computer, there is no misfires in any cylinders and the FICM only drops to 47, but they cannot figure out the issue. I have an EGR delete done...also the truck never did miss or buck at highways speeds even when I had bad injectors! It would only miss first thing in morning and had a rough idle, since new injectors and glow plugs, truck idles smooth. HELP!!!! Truck is getting expensive!

Bucking 06 6.0L
 

I am experiencing the same thing in od. In August I had an egr delete put on. We cleaned everything, new gaskets, the works. We took apart the turbo and ran through the sandblasted at my buddies shop who is a diesel mechanic. This was just extra because the turbo was only 1.5 years old. Changed oil, oil filters and fuel filters. Drove to Florida the next day. Truck ran better than it had since I bought it. There are no codes for injectors. We hooked up to laptop and they were fine. Just started getting the bucking again. At a loss!

Same issue exaclty, ever find a solution?
 

Ever figure this out? I am going through this now. I have purchased a new injector harness, my injectors are all new and testing fine, new TPS, no codes. I cannot go over 60 or it starts doing this and stalling. Runs fine up to 60

Same as Lemming
 

I have same symptoms.
I left truck parked on a hill about 24hrs with 1/4 tank of fuel, the rear was approx 1 1/2 - 2 feet higher.
When started it ran fine about 10 seconds and began to run rough. No power On cold take off. I was certain I'd spilled in some dirt.
45-60 bucks badly and I can drive out of it. I've replaced fuel filters, oil filter and oil. Added 8oz rev x oil add. And rev x fuel add. Driven 100+ miles, no change
No lights on dash no codes.
Any got an idea.

My issue turned out to be a broken oil rail... The oil rail itself had sheered right at the end of the plug on top. From the looks of it, it was a casting flaw that ad grown and finally split under pressure. This effectively killed my oil psi without throwing any codes. Acted like a missfire over 60mph... Truck ran great until the PSI was high enough to start forcing oil out the crack.

I was replacing the injector I thought was bad, took it all apart and checked the injector. after putting it all back together again, I had this feeling that I should check the oil rail and make sure it was seated tight. Sure enough... +1 God. thanks for impressing me to check again. :argh:

Had the same problem with my 05 unplugged the icp sensor and problem went away. On the 03 and some 04 the icp is under the turbo and quite a pain to get to. But on the newer trucks it’s located on passenger side valve cover. If problem stops when unplugged then you should replace icp and pigtail.