Hesitation, low rpms, stalls (1 Viewer)

[Ghostrider I]

Right. '91 HDJ80 about 324K on the clock. Injection pump bumped up 10%, 2.5 inch exhaust.
Problem is when the truck sits outside and it's relatively cold it will sputter and hesitate upon acceleration. No issues with starting. The idle will drop to the point of stalling out. From then it'll start, but it takes a few cranks or one long one. It's as if the throttle pedal is encountering resistance.
After it's been driven for about 20 minutes or so and shut down and started up again, it's normal.

 

[Loober]

Try advancing your timing, rotate the pump towards the engine.

 

[Squash]

If she is fine after being warmed up, then maybe you are still running summer vs winter fuel?
You may have a vaccum leak.
Is the primer stiff or soft before starting?
A primer that takes multiple pumps before resistance means she's sucking air.
Lastly define cold...we've just had -30!

 

[roscoFJ73]

Problem is when the truck sits outside and it's relatively cold it will sputter and hesitate upon acceleration. No issues with starting. The idle will drop to the point of stalling out.

Do you use the fast idle knob? What does it idle at when warmed up?

 

[Squash]

It's been -30C here the last few days.
Both of my diesels grunt, moan and fart until they've warmed up a bit. You just have to learn to live with it.