Walrus, I need your help. 1987 560sl switchover valve vacuum from intake seems to be ok vac, guage shows and holds vacuum. switch # 1 guage shows and hold vacuum. switch # 2 vacuum guage shows 0 vacuum. Switch #3 vac. guage showa 0 vacuum and switch # 4 same as switch # 2 and # 3 0 vacuum. I cheched pod 43 and vacuum guage shows and holds vacuum. Please direct me to the next step . thank you Richard