Throttle spring is where? '78 300D?
 

Hi,

In my (new) '78 300D I found that the throttle linkage doesn't return to idle because there's no spring.

It's a good thing I found this out before I got it started.

You don't want to hit throttle when it's running and have the motor run away due to a linkage problem.

So far I think the spring for this linkage is behind the IP down low somewhat like where a spring is on my '83 Turbo linkage (even though these linkages are very different).

Please let me know if I should look elsewhere because I can't find anything obvious where the spring went.

Thanks for any advice!

-Chris

Chris,

I'm doing this out of memory from a looooong time ago... Look for a horizontal bar that is on the firewall about injection pump height. The clamps and bushings that mount the bar would seize, remove them, clean and lube everything. IIRC the throttle return spring is mounted to the same bar.

Good luck!!!

I have a 1979 300D. If you need pictures of something let me know


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I don't have a 1979 but there is a spring at the bottom rear of the fuel injection pump from the throttle lever down to the rear block to fuel injection pump bracket as well as the one on the that goes to the pivot on the fire wall.

Throttle Spring location
 

Thanks for the replies!

As the car is a '78 300D the linkage is only on the valve cover controlled by the cabled throttle from the pedal.

There isn't a rod going to the firewall.

I will install a new throttle spring down behind the IP with thanks to all your help.

Chris

UPDATE: '78 300D throttle linkage is now understood
 

UPDATE:
Upon further research regarding my throttle linkage in my 1978 300D I found that the cable going to the throttle is only for idle adjustment via the dashboard knob.
I found the throttle linkage actually is moved by the pedal that pivots via a firewall rod to the transmission control rod then back to the linkage by the IP. So I stand corrected on my thinking there was only a cable moving the throttle. Now on learning to adjusting this (odd to me) linkage properly. So much different than my '83 Turbo Diesel but fun to learn more about these W123's.
Chris

I’ve done this before. The spring lives close to the IP. Between the engine and the IP. Pulls on the last leaver that is attached to the IP.

I was able to find a generic throttle linkage spring at an auto parts store that work perfect.