Originally Posted by Diesel911

I was having an inconsistent Accelerator Pedal Movement and inconsistent acceleration. Sometimes I floored the Accelerator Pedal and got poorer then normal acceleration other times it was normal.

I took a guess it was the Firewall throttle linkage as I know the linkages are otherwise OK and my inspection of the Accelerator Pedal inside uncovered nothing wrong.

You can see from the pictures that there is a collar that protrudes through the metal part that cracked off the old one allowing it to move around and at the same time there was too much play inside where the steel shaft goes.

While the rubber part clan also delaminate in my case that was OK.

Replacing it fixed the issue.

I used a genuine Mercedes Part name on the package is Support, Throttle Link part number A 123 400 13 40 however the A is normally not used when you go to parts places.

Also different years and models may use a different part as I believe there is 3 types of linkage setups on W123s.