babason

hello everyone,
Does anyone know what the correct procedure for resetting the throttle valve stop on this E240. 2100612A7122476 Engine 112. automatic 1998/99
Vehicle was running crap (long time to accelerate, and misfiring badly at idle) checked airmass sensor, bad waveform, Replaced airmass, vehicle run a lot better. Only slight delay during changing gears (automatic) and engine felt like it was holding back slightly. Reset engine self adaptation by carring out boot strapping. and carried out road test
Vehicle will now not idle i.e will cut out when you come to a stop at lights or negotiating a tight bend. If you are at a standstill in P/N and rev engine and let go engine will cut out.
No faults in engine control unit, the only thing is the actual value regarding throttle valve stop programmed is saying NO instead of yes in actual values
I think I need to reset this but do not know the correct procedure

Any help will be greatly appreciated

benz-tech

it is very common to see the actual value read "No" in actual values for the throttle stop learned. to learn the throttle stop position, just turn the key to on without starting and wait a minute or so. usually you can hear the actuator ratchet and re-learn.
too fast an idle is usually a vacuum leak, up to a point, then idle quality will be real bad depeding on how large the leak is.
engine dying after letting off throttle could be carbon on throttle plate. clean before setting throttle stop. also throttle will not learn the stop if it has too high of angle to keep the engine running - ie dirty throttle plate.
to assist in learing fuel trim adaption, try driving in 3rd gear at approx 40mph for a few minutes with warm engine, and also moving the throttle as little as possible while cruising at that speed. after that, come to a stop while in drive and let the engine idle for a few minutes (a/c off i believe is also required). this should reset the partial load and idle fuel trim values.