Throttle jamming mercedes608 LT2 1983

[Aerial]

Heya,
My throttle is jamming on high revs and the peddle doesn't return to idle if pushed all the way down. Often the throttle to cut the engine will jam on high revs. I can get the truck to return to idle by moving the arm connected to the engine. If I disconnect the peddle it moves freely. Does anybody have any advice. I posted this in the wrong place - will try to delete and repost

Thanks in advance

 

[Aerial]

Heya,
My throttle is jamming on high revs and the peddle doesn't return to idle if pushed all the way down. Often the throttle to cut the engine will jam on high revs. I can get the truck to return to idle by moving the arm connected to the engine. If I disconnect the peddle it moves freely. Does anybody have any advice.

Thanks in advance

 

[Rockron]

Perhaps the arm as you describe it, is missing a return spring?

 

[Aerial]

Perhaps the arm as you describe it, is missing a return spring?

The spring is there and attached.

 

[clarkmichigan55b]

Try disconnecting the throttle linkage at the fuel pump then with the engine switched off move the fuel pump lever to full throttle to see if it sticks open.
If ok check the rest of the linkage for seized joints.

 

[Rockron]

Is Bowden cable from accelerator peddle to throttle sticking ?.

 

[Aerial]

The spring is there and at

Is Bowden cable from accelerator peddle to throttle sticking ?.

I'm not sure,

Try disconnecting the throttle linkage at the fuel pump then with the engine switched off move the fuel pump lever to full throttle to see if it sticks open.
If ok check the rest of the linkage for seized joints.

Thanks , I'm learning.
It only seems to get stuck when the peddle is connected. When i disconnect the lever to the peddle the spring returns. Once i connect the peddle and full acceleration , it sticks. I opened the dash to see if the cable is getting stuck somehow as it goes under the bonnet and I looks fine. The button on the dash to cut the engine also gets jammed on full acceleration. Will put some photos. I've ordered a new cable thought it a good idea to seek advice in case it was something obvious. I was going to give everything a clean this week.

 

[Rockron]

Cable attachment of course is at the other end of the shaft that goes through the engine block ie the opposite
end to which the spring and ball jointed operating lever attach.......as shown in your pic.
Your other pic. shows what appears to me is the fast idle adjustment knob, yet another cable attachment which simply enables the engine to run faster on a cold start, adjust as required.
If you follow the cable from pedal to shaft end attachment there's a swivel lever, this can gunge up and stick even if you replace the cable, I'd give that a good going over on your clean up.
Bear in mind I'm more familiar (certainly no expert) with the later OM 364 version of that engine and taking a guess that they're
similar in many respects. Best of luck getting it sorted.