For Mercedes SL W113 Pagoda all models: - 230 SL (113.042) from 07/1963 to 01/1967 - 250 SL (113.043) from 12/1966 to 01/1968 - 280 SL (113.044) from 01/1968 to 03/1971
The vacuum cap attaches to the igniter and takes advantage of the igniter's movement to create a vacuum of air using an internal membrane. If your vacuum system isn't working, it may be the cause.