I have a problem with 2012 XC60 T6+LPG. Engine is idling roughly, especially when cold. Coil packs are Ok. There is no noticeable vacuum leak in the intake. I can't safely rule out fuel supply problems. When the engine is warm, the ECU appears to want a leaner mixture (STFT <0) and once run on Petrol it prefers to have to richer (STFT >0). Also, it misfires to single cylinder on Petrol so I still assume there may be a problem with this particular fuel injector.

enter image description here Is it normal to have such messy Ignition angle when idling? Is it a consequence of misfires or is it a reason for misfires and caused by some other problem?

Live data video: https://files.anuzis.lt/d1dec80a2b.mp4

OBD codes get caught after leaving the car idling for a longer period: * P0300000 Random Misfire Detected * Also misfires in each cylinder P0300100-P0300600.

  • 1
    Welcome to the site! Do you have any OBD codes?
    – GdD
    May 2 '19 at 7:27
  • They come and go. Car registers misfires in every cylinder and random misfire OBD codes. OBD codes are only caught if I leave the car idling for a longer period of time, ex. at a shopping center waiting for my wife :)
    – flyeris
    May 2 '19 at 7:40
  • What are the codes you get? Please edit and add them as they may be relevant.
    – GdD
    May 2 '19 at 8:21
  • Check the engine temperature sensor FIRST. The ECU determines the correct mixture based on this temperature. The ECU will not detect this sensor as faulty if it's reading is not out of range. But the sensor might show incorrect value. For example, when engine is cold and outside temperature is 5 deg Celsius it might read 40 deg Celsius, causing the ECU to make an incorrect mixture for the actual temperature. When the engine is cold measure the outside temperature and it should roughly match the reading from the sensor. If not, sensor should be replaced.
    – BJovke
    May 3 '19 at 9:26
  • @BJovke - Thanks, point noted! Will do that first thing tomorrow ;)
    – flyeris
    May 3 '19 at 11:54

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.