Main.TrailIndexPage | Fuel System | Throttle

Throttle

This component is part of the Fuel System.

Definition

  • Its technical name & common name(s)
  • part # - start year & end year
  • which area it belongs to - engine, transmission, body, injection etc, link back to the relevant section

Function

Describe, in general terms the function of this component. Meaning what is it there for and what role it plays. Describe how it works, the inside mechanism. Use diagrams to explain.

Describe common maintenance procedures, and common faults that may occur. Describe how these may be diagnosed and resolved. Again, include diagrams, photographs and explanations. Where possible, include measures, tolerances, weights etc.

  • Symptoms when it faults
  • How to test if it is faulty - what tools to use
  • How to fix / change

Link to related components where appropriate.

Throttle Body

According to 230 SL Spare Parts Book (Edition C):

  • UP TO ENGINE 10786 (manual 10/20), and 2990 (auto. 12/22): VACUUM ADVANCE.
    • Distributors (Bosch references): VJUR 6 BR 49, 0231 116 046, 0231 116 050. Note: Bosch 0231 116 046/050 is now replaced by 0231 185 007, 0 227 100 911 (MB Ref.: 002 158 35 01)
    • throttle body (MB Ref.) 000 140 39 53
  • FROM ENGINE 10787 (10/20) and 2991 (12/22): VACUUM RETARD.
    • Distributors (Bosch Ref.): 0231 116 047, 0231 116 051. Note: Bosch 0 231 116 051 was replaced by 0 231 185 009
    • throttle body up to engine 14471 and 5668: 000 140 49 53 (replaced by 000 140 55 53 with some pipes and clamps).
    • throttle body from engine 14472 and 5669: 000 140 55 53

Picture below shows a 230SL Throttle body with vacuum port on top of the body. Note also that the actual port is on the air filter side of the throttle butterfly. With engine idling and throttle closed, the vacuum reading at this port would be zero. That means it is suitable for Vacuum advance distributors only.

Picture below shows a 230SL Vacuum Retard Throttle body. Looks similar to the Vacuum Advance body above but the vacuum line from the distributor connects below the body.

The throttle body below is from a 250/early 280 Engine. Note the vacuum pipe attaches to the bottom of the body (vacuum retard type). Also, the vacuum port is on the 'engine' side of the throttle butterfly and with engine idling and throttle fully closed, there would be maximum vacuum reading at the port.

The throttle body below is from a later 280 engine. Note the vacuum pipe attaches to the bottom of the body (vacuum retard type). Vacuum port similar to the body above.

The throttle body below is from a very late (70/71 U.S.spec) 280SL. Even though the vacuum port is on the top side of the body, it is still on the engine side of the throttle butterfly and has vacuum all the time the engine is running. The vacuum to the distributor is controlled by an additional relay so that at engine oil temperature below 17 degrees C or water temperature above 100 degrees C, the vacuum to the distributor is cut off, advancing the timing and increasing rpm during engine warm up and when the engine is running hot. At idle and during over-run conditions with the throttle closed, vacuum is applied to the distributor, retarding the timing to Atdc. The helps reduce NOx fumes.

05 December 2007, at 07:49 EST

Dashpot - Throttle Damper

W113 cars with manual transmission have a throttle damper or dashpot that prevents the throttle from returning to idle too quickly, that is, when the engine is revved and the linkage released, the engine should not return to idle immediately, but should gradually slow to idle over a couple of seconds or so. It also prevents a lot of the shock wear of the ball joints in the linkage.

The adjustment of the dashpot should be checked as follows (BBB 00-16/4): Slowly actuate the control shaft until the control lever (7) is just about to lift from the dashpot pin (6) (Fig. 00-16/8).

The original Mercedes dashpot(p/n000 070 02 67) for a long time is no longer available. The original had the following dimensions:

The plate or bracket for the dashpot shown above [(5) in Fig.00-16/8] was only present on 230SL cars, the 250SL and 280SL cars had a shorter one without a pin hole as shown here:

Fortunately many vintage American cars used similar dashpots and the task is to find one with a long thread part and a long front part. Some possible Buick or Mopar parts that might fit are discussed here:

http://www.sl113.org/forums/index.php?topic=16057


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