Throttle linkage

[M Paul Lloyd]

Hi all, I hope this is the right place for this, apologies to the mods and admin if I am wrong, sorry.
Anyway I have a W202 C200 which is quite frankly brilliant and I am happily finding my way around the various components and reveling at the shear quality of the workmanship.
However, given that it is now some twelve plus years old its not without its foibles and just recently I noticed the accelerator pedal was hitting what I can only describe as a 'tight' spot around 1000 rpm. Many an 'expert' was on hand to suggest it was 'the ECU' and would cost a packet, although on closer examination, the box which supposedly houses the much fabled 'ECU' is in fact empty, but more of than another time perhaps? Meanwhile I had a quick look at the throttle linkage (see picture) and was horrified to find that the upper parts including the return springs and cable were plastered in a thick sticky grease the cams and linkage underneath were bone dry. So I did a quick scrub with WD-40 and a toothbrush followed by the application of some lithium based grease and would you know it? The accelerator pedal works just fine now, no 'tight' spot and most importantly no expensive component change.

 

[Sway]

Brilliant! I know how you feel.

I own a W202 C280 and i lubricate the accelerator cable once a year. It makes a big difference!

 

[M Paul Lloyd]

Bit of an update on this one.

The lubrication thing only seems to last a short while before the problem comes back.

On closer inspection I have noticed that the lower cam, that is actuated by the throttle cable which in turn operates a vertical ball ended linkage of about 120mm in length, seems to be prone to wear. I have since adjusted the turn-buckle on the vertical link increasing its effective length buy some 6mm so that it takes up the apparent 'slack' in the cam follower and as a result all sense of the previous hesitation and 'tight spot' has been eliminated.

Obviously in the longer term I will need to replace the cam which will no doubt involve purchasing a full kit of parts (or worse an entire throttle body) but as a stop gap it is well worth trying, just don't overdo it as you have limited adjustment before you exceed safe limits on the threads.

 

[television]

Bit of an update on this one.

The lubrication thing only seems to last a short while before the problem comes back.

On closer inspection I have noticed that the lower cam, that is actuated by the throttle cable which in turn operates a vertical ball ended linkage of about 120mm in length, seems to be prone to wear. I have since adjusted the turn-buckle on the vertical link increasing its effective length buy some 6mm so that it takes up the apparent 'slack' in the cam follower and as a result all sense of the previous hesitation and 'tight spot' has been eliminated.

Obviously in the longer term I will need to replace the cam which will no doubt involve purchasing a full kit of parts (or worse an entire throttle body) but as a stop gap it is well worth trying, just don't overdo it as you have limited adjustment before you exceed safe limits on the threads.

This reminds me of the damage done years ago when all car had carburetors,, the huge return springs often quickly wore the spindle for the butterfly allowing air to get in with a poor idle. No real advancements have been made in this area