Sticky Throttle Linkage on 85 300sd

[fattyjr]

Hi, I have a 300sd with a sticky throttle linkage. I took apart each piece of the linkage to see where it was getting stuck. The linkage rod that goes from the IP to the "Stop" lever gets stuck in the fully open (or down) position.

Does anyone have any ideas if my IP is bad or is there a easy fix?

Thanks

[toomany MBZ]

There is a plastic bearing, blue circle and red arrows, that should turn on it's axis, just like any other bearing, make sure that's happening.
Other arrows point to bushings, clean everything up and see if that helps.

[Biodiesel300TD]

My 300TD had a couple sticky spots, and it ended up being caused by the innards of the black box on top of the valve cover. I ended up taking the innards out and blocking off the vac lines to it, and the sticky spots went away. But also check all the pivot points to make sure they aren't gummed up. And try cleaning lubing all the ball and socket joints.

[fattyjr]

Hi Thanks for the reply. I have tried cleaning the assembly on top, but it still sticky. When i removed the linkage from the Stop lever to the IP and pushed it down it stayed down and didnt spring back up. It is also very stiff to move. We checked the same linkage on another 300sd and it move more freely.

Any thoughts?