Starting my 420 SEL is very difficult and the car runs very "lumpy" missing and spluttering after many attempts to start.
I notice that the air pump is not engaged when startup occurs but after a few minutes the clutch engages and the car begins to idle ok.

The clutch on the airpump then disengages when the engine warms upand the car runs well slowly and on the highway.

Starting the car after it is warmed up is not a problem ....she starts first time.

When the engine is cold again the same problem re-occurs and she is difficult to start.

It seems to me like the airpump is working ok but is not being activated on startup? Can anyone help?