How do you properly adjust the Throttle Linkage - PeachParts Mercedes-Benz Forum

Diesel911 · #1 09-14-2008, 07:09 PM

Unfortunately the online manual site is gone. Also there is more than 1 style of linkage depending on what year and model you have.
When I first got my car the linkage was extremely sloppy and I had no Manual. I felt it was safe to adjust the linkage (under the hood) in 3 places. I started from the Gas Pedal up to the Fire wall.
Next On mine the pivot on the Fire Wall rotates a steel rod; on that steel rod I found a small bolt with a 10mm head and noticed that one of 2 parts it held together had an adjustment slot.
After that the linkages goes up to a complicated Bell Crank where the Cruise Control, Manual Shutoff and other stuff hooks to. I buy passed and left alone all of that as like you I had no manual.
After bypassing as stated above I went down to the Throttle Arm on the Fuel Injection Pump and shortened the length as much as I could and still allowing enough play so that it rested against the Idle Stop (you do not want the idle set with it hanging from the linkage, you want the throttle arm to rest on the idle stop).
Taking the slop out of those 3 areas allowed the Fuel Injection Pump Throttle Arm to move to the fullest of it's range. This gave me better response at the Pedal and more power.

dannym · #2 09-15-2008, 08:20 AM

ForcedInduction posted the manual here:
http://www.peachparts.com/shopforum/showthread.php?t=232254

There is a section with all the linkeage lengths for various models.

DeliveryValve · #3 09-15-2008, 08:27 PM

Quote:

Originally Posted by dannym

ForcedInduction posted the manual here:
http://www.peachparts.com/shopforum/showthread.php?t=232254

There is a section with all the linkeage lengths for various models.

Looks like FI's zip file is empty. I think I have a .pdf procedure somewhere.

dannym · #4 09-16-2008, 07:08 AM

It's not empty. Download this:

http://rarlab.com/

DeliveryValve · #5 09-16-2008, 11:54 AM

Quote:

Originally Posted by dannym

It's not empty. Download this:

http://rarlab.com/

:

Actually, FI just posted the HTML menu as per topic of that thread. The .pdf is too big to upload. In fact I was having trouble uploading my .pdf, but had to converted it to these images to do so.

To CJ, I hope this helps. You might need a magnifying glass to read them.

Wusha · #6 06-21-2019, 11:35 PM

Quote:

Originally Posted by Diesel911

Unfortunately the online manual site is gone. Also there is more than 1 style of linkage depending on what year and model you have.
When I first got my car the linkage was extremely sloppy and I had no Manual. I felt it was safe to adjust the linkage (under the hood) in 3 places. I started from the Gas Pedal up to the Fire wall.
Next On mine the pivot on the Fire Wall rotates a steel rod; on that steel rod I found a small bolt with a 10mm head and noticed that one of 2 parts it held together had an adjustment slot.
After that the linkages goes up to a complicated Bell Crank where the Cruise Control, Manual Shutoff and other stuff hooks to. I buy passed and left alone all of that as like you I had no manual.
After bypassing as stated above I went down to the Throttle Arm on the Fuel Injection Pump and shortened the length as much as I could and still allowing enough play so that it rested against the Idle Stop (you do not want the idle set with it hanging from the linkage, you want the throttle arm to rest on the idle stop).
Taking the slop out of those 3 areas allowed the Fuel Injection Pump Throttle Arm to move to the fullest of it's range. This gave me better response at the Pedal and more power.

Sorry to resurrect but I’m in desperate need of help. How did you reach down to the throttle arm?

I have about 1/4 inch of unused throttle until it can hit the WOT stop.

Diesel911 · #7 06-22-2019, 12:07 AM

Quote:

Originally Posted by Wusha

Sorry to resurrect but I’m in desperate need of help. How did you reach down to the throttle arm? Do you pull the linkages or adjust while they’re on the ball joints?

I have about 1/4 inch of free throttle until it can hit the WOT stop.

It might help if I knew what problem you were trying to fix.

The Throttle Lever is that lever on the Fuel Injection Pump. You reach down between the Fuel Injection Pump and the Engine Block (better when everything is cold) and simply keep it from moving. Then have someone slowly step on the accelerator and see how much play is in the linkages.

If you have play you also need to determine if the play is due to a worn out pivot mount on the fire wall or not.

See of you linkages matches the one in the attached pic where a bolt on the linkage is circled in red. You can take up some play by loosening that bolt and rotating the linkage and tightening it down.

Look for wear where the part on the one pic with the Green circle goes through the Metal.

The linkages with sockets have specific lengths that you need to reference in the Factory Service Manual. The measurements are from the center of the socket to the other center and can be done with the linkage removed.

There is another measurement/adjustment in the Factory Service Manual that requires a little metal disc to be inserted but I have never done that.

Someone will have to post the site of a free only W123 manual for you. Also there is more then one linkage setup.

Junkman · #8 06-22-2019, 08:09 PM

Quote:

Originally Posted by Diesel911

There is another measurement/adjustment in the Factory Service Manual that requires a little metal disc to be inserted but I have never done that.

If you're referring to the disk with a hole in the center, the disk can be approximated by drilling a 1/8" hole in the center of a US nickle. Two nickles glued together would be fancier still. I forgot the details but they are in the 126 FSM and relate to the 617 engine.