Throttle Body Tech Needed
 

I need a tech with some experience with the Euro models. I have a 117.962 engine and pulled the throttle housing to make sure that no vacuum leaks where present.

I was surprised to find the bottom port on the throttle housing open. It is missing the extension tube and the port does not pass into the throttle body. It has a plug type device that diverts it back to open air. Manual shows the top port for EGR and bottom for Vacuum switch, which I don’t have. SO do I need this bottom port?

On the other side of the throttle housing the 3/2-way switch is missing. In my manual (US) it shows a mechanical/pneumatic switch over valve that connects to the warm-up compensator – lower chamber. The valve is responsible for full load enrichment via the warm-up compensator. Prior to 1981 the lower chamber was open to atmosphere.


1983 500SL 117.962 engine, 107.046 chassis, emissions CAT only.
Warm-up Compensator is Bosch 436 140 101. Manual 7.3-120 checking fuel pressure does not list my compensator.

Thank for help, advice, or assurance.
http://webpages.charter.net/meduke/throttle1.jpg http://webpages.charter.net/throttle2.jpg

Second photo
 

Last Try Photo
 

You may want to call Bosch directly and ask to speak to a tech rep. They are usually very helpful.

Bosch Customer Service:
888-715-3616
(Monday thru Friday 8:00 am to 5:00 pm CST;
for U.S.)

Thanks for the phone number!!!

They did clear up questions.

Euro 126 throttle body
 

Yours is exactly correct as is. It does not have that vacuum switch referred to in the U.S. verion manual. You also do not have EGR.