Hi All,

I have problem with my Mini Cooper S 2003 during engine start. On cold/warm start engine goes to about 2000rpms. There is probably a problem with rich fuel mixture which is caused by wrong air calculation. I checked for error codes on ECM and there was nothing. Also, when I disconnect T-MAP sensor, the error code is showed (OK). But, when i disconnected MAP sensor (cooper S), no error code was showed (tried few times even on running engine). Why ECM didnt show the error code? It looks like ECM doesnt know about that sensor at all Do You have any ideas? Had similar problems (on this/or other sensor)?

Regards,
L

 

If the engine tends to race at idle and otherwise performs somewhat normally, it's often a sign of a large vacuum leak somewhere or possibly binding throttle. Such a leak can cause a low vacuum condition on the non-boost side of the intake (before the supercharger). This can make the reading coming from the MAP sensor to be roughly the same as the ECU would see if the sensor was disconnected, so the ECU is not 'concentrating' on that input. The TMAP is the primary input for the ECU in determining fuel mixture, the MAP is used mainly for barometric readings and baseline calibrations.

 

Thanks for reply!

Is the MAP sensor connected straight to ECM? Maybe there is some small control module which might be broken? I think Bentley's service manual is not precise at this point and i cant find connections from MAP sensor to ECM on electric diagrams (they say something about B6063 Intake vacuum sensor but no MAP sensor is showed). Do You know the PIN number on ECM which corespond to MAP sensor on Cooper S? Probably I should start figuring out if there is a signal from the MAP going to ECM...

Best regards,
L

 

sounds like a vacuum leak to me, unless you have a smoke machine, try spraying the intake and vacuum hoses with brake kleen, (the flammable kind) with the engine idling, you should see a change in the idle when the fluid finds the leak,,,,,,,,,be warned if you spray the exhaust you could set the car on fire.. be careful!!!!!!!!!!!!!!!1, i have found multiple leaks this way and have not yet set one on fire. try this at your own risk...

 

WD-40 works too.