David, with the pot connected and engine idling, others have posted you should read 0.7V measuring betwen the middle pin and ground. If it is off by more than 0.25 Volts from that, you should incrementally adjust it by rotating the pot.
You might want to consider adding a 'signature' line to your posts mentioning the 300E, considering your user id.
'91 MB 190E 2.3
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