BMW 318i ,1993,Vin:WBACA0209OAD69828,Bosch M1.7.2Archived Message
Posted by John Gijsbers on April 16, 2008, 12:26 pm
Hallo this BMW is giving us a bit of a headache!When it is cold and warming up it idles and runs ok.When it gets warm(operating temp or just below that,) it surges at idle, but not continually,(it will not stall but sometimes almost does), and it has a bad hesitation/surge at high idle/cruise(2000-3000 rpm)bad enough that it feels like no power.I have been unable to pinpoint it to any particular cylinder) If you manage to go above the approx 3000rpm engine speed it is ok again! It has set no codes, fuel pressure and flow are ok(2ltr/min,@2.5-3 bar)We tested all the sensors(with scope) and as far as I can tell they test ok! Ignition scopes ok. We have replaced spark plugs,a split breather hose, and I swapped coil pack complete with leads from a known good car to try but that made no difference at all! It has a vane type airflow meter, which tests ok(with scope)and seems mechanically sound..When the engine gets really warmed up( after lets say 45minutes of testing in the shop(with engine running constantly)it improves and runs near perfect!We have been unable to pinpoint any problem and already spent far too much time on the vehicle!(And the lady customer has been very patient!) Has any of you guys come across anything like this? Thanks in advance, John Gijsbers