question for stevebfl or anybody

[josev]

took my car to a place that works on mercedes
they said my fuel distributor is bad because car is running on 5 cylinders at idle #6 is dead at idle the tech swap the tubes that
feed the fuel to the injectors from 5 to 6 now dead cylinder is # 5
but the tubes are not clog. said price is $1300
so i took it off spray the **** out of it with carb cleaner and tap the side with a hammer incase there might be a piece of dirt inside of well car is now running fine but i need to know where do i put the test probes of my volt meter to check the EHA
as for i turn the mixture screw in a few times also is it in mv or ma
i know the spec is 800 but at idle or at 2000rpms
thanks jose