Back to Forum
Post a Response
    BMW 520i/ 2002 /22-6S-1 / WBADT1204OGY77445 Archived Message

    Posted by david stock on January 15, 2008, 7:32 pm

    Can anyone help with this one..

    This car developed a misfire on motorway. Taken into a local garage who changed the plugs and 'messed about' a bit..... this made no difference. I did a code read and found misfire codes on cylinders 1/2/4/6. I reset them and took the car for drive. Misfire stil there but now the only code present is for cylinder 4. I guess the other codes may have been the garage 'messing about'. I told them to change all the coils and test drive. They called me back next day.The dealer only had 2 coils in stock so these had been fitted to cylinder 4 and the other one was tried in various other cylinders. The Misfire code on Cylinder 4 is still present and reappears within a couple of mintues of being reset.
    The coil trigger signal on cylinder 4 is the same as all the others. What I have found is that the injector trace on cylinder 4 is only present for 20 seconds after start up and then disappears. I presume this is the ECU shutting down the Injector as a safety measure because of the misfire...? Emission readings are CO =0.13%/ HC=133PPM/CO2 = 13.8/LAMBDA= 1.20.
    I've also checked for manifold air leaks....
    Coil primary readings on 'old' coils is 0.1 ohm and on the new ones 0.2 ohm.

    What else can I check....

    cheers

    Message Thread:


Copyright © uk autotalk