Idle stumble when cold...And other stuff

[dhirocz]

Just came in from swapping my doser and turbo actuator. Got a few questions.

Actuator was installed with insite. New one works well. My VG ring has one hell of a notch in it but still moves OK otherwise. Was a good bit of soot under the actuator. I have a newer spare turbo that has a somewhat stiffer VG ring but moves smoothly. Would you swap it?

Replaced my doser...It was leaking coolant. I noticed I had NO fuel come out of the doser fuel line when I swapped it...Is that a sign of a faulty shut off valve?

Behind the Delta P there are two sensors on the block. The one at the top is leaking oil...And for whatever reason, I cannot find what it is. I'm assuming it an oil temp sensor...? I already changed the pressure sensor for the same thing.

Recently, the truck has developed somewhat of a stumble that resembles an intermittent misfire when warming up, at idle. When it's warm, I don't notice this. I have no codes right now. Insite is not failing any tests. During prime, I can hear what sounds like the lift pump changing pitch like the load through the pump is changing. I also hear a change of pitch at the moment it stumbles though I'm not sure that's where it's coming from. Lift pump puts out 26 while pumping, holds 14 with the key on, engine/pump off. FRP at idle is 250. I have not monitored any fuel pressure fluctuations during the stumble, but it's very brief and insite might not be refreshing fast enough to pick it up.

I plan on pulling the actuators and cleaning/inspecting them next, but could that pump cause that? As far as I'm aware the gear pump and lift pump are original.

2010 CM871 685k miles