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drehzahlschalter & relay noise

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I'm trying to figure out what to do with two devices mounted to the firewall above the brake booster.  One of them is the legendary "drehzahlschalter" (bosch 0 335 530 006), and I've found some information in old forum posts.  The other is a relay (bosch d 332 100 020) and it started making noise today.  I believe that these are emissions-related devices, though I don't understand their exact function.


The original carburetor is long gone, it was replaced by a manual choke Weber 32/36 sometime before I bought the car in 1988.  After a long storage period, I installed a new electric choke Weber 32/36 during a 2015 restoration.  This is a smog head engine (no pump), so the only plumbing is what's needed by the Weber and for crankcase ventilation.  The EGR and all other emissions contraptions are not hooked up.  With one window or the sunroof open, I get some engine smell in the car on long periods of deceleration, but otherwise the car runs well.


Earlier today, I disconnected the two devices and the car starts right up, but I've not taken a drive.  It seems that I don't need these devices.  I'd appreciate any thoughts on the need for those devices (and what they do), as well as the deceleration issue.





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on my 74, all that was removed, including the wiring harness, if you un-tape the harness a long ways back, you can remove the wiring that ran to those items without cutting any wires. It was a total add on, timer box, dash pots, etc., including ERG valve and plumbing, but you will need to plug the exhaust manifold up, the muffler shop here welded a plug into the fitting that is right there at the exhaust manifold that connects the steel mesh and pipe. Running just the weber 2 barrel, and a non-vacuum advance distributor.

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