I've just bought a W123 230E, two months ago.
A few things keep me wondering :-
(1) Everytime I stop, change the gear (auto) to parking(P), the idle will become very high.....until I press the accelaretor.....
(2) The ex-user installed the air-horn, so I have one selector switch to allow me choose either one.The air-horn work intermitently but the default/original horn is working perfectly.
What could it be ???
(3) Its difficult to start when the engine is warm during hot weather.I've to keep on pressing the starter until it start., and when it start..it will slowly (take few second) to take into the normal idling, as well as the fuel pressure meter..
But when the engine is warm, in cold/night time, it's easy to start (same as early morning).
Could it be the fuel pump/relay/fuel-filter/coil ??
Is it possible to test to change the fuel filter (cheaper) only without changing the fuel pump relay ??

Thanks for your kindest help ..

Kareem.