I seem to remember reading that Volvo used an electrically operated air slide in early 240s. The spring loaded one in my 164 works fine in warm weather but stays a little open in cold weather and idle stays too high. Does anyone remember which 240s had the electric air slide and how to connect it. And, most important, can I set it up in the 164. Thanks for all input

In my efforts on the Yellow Peril (a 1973 145E) I found I had a collection
of Auxiliary Air Valves but NONE of them would close. So I am installing
a electric one from a 240 (which I understand the later 164s and ALL
CIS injected B20s used). I had installed it but had a high idle condition
(which you may have noticed in my previous posts) so I removed it. I plan to
put it back on today and will report on how it worx.
--
George Downs, Bartlesville, Oklahoma, Central US

Your 1972 Air Bypass Valve is controlled by the coolant water temperature, so if your thermosadt is working properly and the engine is getting up to the proper operating temperature, then it should be closing (unless the valve itself is faulty)- and the ambient air temperature should have little or no influence on the valve operation.

Maybe your thermostadt is too cold ??

Also, you could remove the valve, put the sensor part of it in a pan of water, and heat it up on the stove. Monitor the water temp with a cooking thermometer and watch to see at exactly what temp the valve closes.

My thermostat was too cold. It was fine in South Africa which has warmer weather, but here in New Zealand with 20 degrees colder weather my car would not get up to temperature. And that made more of a difference in performance on my carburettors than on your FI! So I agree with Chris.