hello guys
I have a stilo 1.6 dynamic 90 000km. I have a problem with the idlle speed.the engine seems to have a hard time keeping a constant idle speed and sometimes the engine just stops.it doesn't keep idling constant at any time.till now 3 of the 4 coils have been changed,of course the broken one were SAGEM.Could this problem be from the spark plugs?

Could be a number of things really from updates to the ecu/throttle body to Idle control valve plugs air leaks on manifolds you will have to work your way through the list and delete the possible problems one by one

Assuming your plugs and air filter are in good condition, then i would gain access to your air inlet valve (idle valve) and inspect and clean, then do a battery reset by disconnecting battery for a few hours to reset everything and let it relearn best settings.

If not then it's off to dealers for the ECU/ throttle body update for you

went to fiat service today ,changed the spark plugs and they also cleaned the throttle body.the engine runs better but still has problems with the idle speed.were exactly is the idle speed control valve?is it in the throttle body?is it necesssary to reset the ecu by disconecting the battery?

is it enough to disconnect the battery for a few hours and then start the engine to reset the ecu?

Did they check you had the throttle body ECU update?

Yes look for the tube from the air filter and the first thing the air goes into on the engine

a week ago I did a reset to the ecu by disconnecting the battery for a few hours and YES the idle speed it OK now!!!!But another problem apeared since i have changed the spark plugs,cleaned the idle speed valve.The engine has a vibration that grows with the engine rpm.It feels like a diesel and has a little loss of power!!The spark plugs are NGK BKR5EZ.ADVINCE NEEDED!!!!
I have to change the oil and filters in 500 km.

coil?