Yep, that "mushroom thing". However, if you don't have places for two vacuum lines, then don't plug anything. Only if you have two lines (one points to front of car other to rear) do you want to plug the front.

My experience with plugging the air-bleed hole would indicate that if the car died then the idle mixture screws are set too lean (in too far) AND/OR the carb is not adjusted correctly for the idle circuit. Again, Stevebfl would be more expert in that than I but it is how I "think" I remember it when I had the Zeinths.

Dan

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Dan Taylor/ Tulsa, OK MBCA
'84 300D/'90 Jaguar XJ6/XJ40