In the course of diagnosing a rich-running condition, I removed the alloy housing between the fuel pump and the "temperature feeler" (the car is a 1965 230SL). This housing contains a valve that, when the motor is cold, allows auxillary air into the intake manifold and enriches the mixture through the fuel pump rack.
Near the top of the enrichment valve housing is a potmetal casting with a 14mm steel nut threaded onto it, which when turned manually closes valve, cutting off auxillary air and fuel enrichment. This assembly appears to be staked in with a tiny steel roll-pin.
My problem is that this arrangement was somewhat buggered up by a prior owner. The steel nut does not turn the potmetal casting (probably someone tried to force it when the potmetal was siezed by the alloy housing). The steel roll-pin would not allow the piece to turn in any event (thus defeating the entire purpose of the potmetal piece, which is to diagnostically rule out the enrichment valve as a problem when the motor is warm). The local Mercedes dealer has no drawings of how this assembly is supposed to look, and the parts manual shows no detail (it only has major parts as units). Presumably, anything useful would have to come directly from Bosch?
So, any assistance in pointing me to technical drawings of the enrichment housing assembly and/or parts sources for the little bits would be appreciated. Perhaps there is an elderly employee that Bosch forgot to retire who would know about this?
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