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On 12 Dec 98, at 13:01, James MacNaughton wrote: > What does that mean? > Early versions of the 70-1 and 72-3 switches must be adjusted with > an Ohmmeter or one of the Bosch FI testers. > > How would I know what version I have, and what would the ohmmeter > settings be? The setting instructions are given in the Bentley manual. Basically you are using an Ohmmeter to look for some sliding contacts to make or break a circuit inside the switch. I have to look at my manual every time I do one of these. You need to determine which two TVS contacts connect to the idle switch contacts and move the TVS until those contacts just change and then will change back just as the throttle opens. You should verify that this changes state every time you open the throttle. This is not an adjustment that needs to re rechecked periodically, more like every time you rebuild the engine. > Late versions of the 70-71 > and 72-3 switches are adjusted by turning the switch just until you > feel the switch just come up against, but not past, an internal > stop. > > I don't know as I've felt said internal stop, but I'll check just as soon > as I get home. Because of the lack of an audible click which made the 68-9 switches easy to check and to verify, Bosch introduced an internal stop in around 73. Thereafter all replacement switches have this stop also. So original 70-1 switches do not have it and original early 72 switches do not have it either. This internal stop has a tab that is bent at the factory to stop the rotation at just the right point. You must be careful when adjusting these that you do not turn the switch up to the stop and then turn it just a bit more for good measure because that will cause the throttle valve to open slightly, resulting in a too fast idle. Jim - ******************************* Jim Adney, jadney@vwtype3.org Madison, Wisconsin, USA ******************************* --------------------------------------------------מת> --------- List info at http://www.vwtype3.org/list or mailto:help@vwtype3.org