Hi there.

I have a problem with this symptoms: when in neutral or with clutch pressed down revs drop down below 500, usually shuts down the engine. It shuts down almost 100% if drops from 3000rpm or more. It happens while driving or standing in place.

I have solved a problem twice before buy following the "guide" for cleaning the inlet control valve, but doing it yesterday did not help.
Now, little difference is that car runs perfect, pulls etc. No problem with that.
When started, engine runs at 1200 rpm and slowly lowers as it gets warmer. No problem at that rpm rate, but as it comes to normal idle 750-800 rpms, problem starts.

I have noticed that inlet valve moves little bit easier at first few millimeters when pressed down with hand (finger). There is more opposing force when it is opened more. Is that OK?

What should I do myself before going to service, if there is anything to check?

Thanks.

could be a fault with maf or throttle position sensor or indeed the throttle body.. retrain tps and check if there are any faults logged (you could also check/clean engine and ecu/injection earths and corresponding plugs.. ensure all software updates/recalls are done) beyond that it gets much more interesting

12, thanks for suggestions.

Now, when thinking of possibilities, I have cleaned the inlet control valve about a month ago, maybe more, but still this year, probably 2000-3000 km ago, and the body around the valve has managed to get dirty black for that short period. The amount of "dirt" is not big, its like a thin layer of very black almost dry filth, witch is easily cleaned with WD-40 like spray.

Is it possible that some other components there (you have mentioned some) got dirty like described above and need to be cleaned?

You can try contact cleaner on the MAF sensor (that’s the wire sensor sitting in the throttle body) but, from experience, that won’t give you much go. As you problems begin after the warm up cycle (when the ecu enters closed loop state and thus cuts extra RPM/fuel and starts running on sensor feedback) your issue may not be related to the TB at all. There was a chap here with a similar problem a while ago and, for the life of me, i could not figure out what was at fault (you may try searching for that post using “throttle body” and “stall” as keywords as there was a lot of other advice given by the more knowledgeable members). Soo... you could have a problem with Lambda or injectors or engine ECU or TB actuator or TB position sensor or, possibly, other bits.. I would advise to give TB a good clean using carb cleaner (NOT WD40) and a fine toothbrush on the hinge/pivot points (+use electric contact cleaner on the MAF sensor and all the corresponding plugs) also clean (again with contact cleaner) engine earth and ecu/injection earth (engine earth is low down accessible from below; ecu earth is top left side of the engine at the back if you are facing hte engine.. follow a thick black wire off the injection rail to the engine head). You would also do well to see if there are any error codes present and repeat the re-learn procedure a few times.. that’s all for now.. let us know how you get on

Thanks again 12. Actually, yesterday I have done all the connector cleaning - 2 on TB, the famous D4 connector and one near it, and cleaned the TB and the sensor within. And look, the problem is gone! A suspect the sensor in TB, because I soaked the damn thing now with that spray (not WD-40 like but kind for cleaning the electrical contacts specially) I should be happy now, and I am, but I had to do it 3 times for last 2 years and 22000km only. Is that such a bad technical solution implemented in Stilo or something else, like bad new air filter or bad luck?