Hi im new to this forum and not sure how all of this works. so if this problem was brought up before i apologize. anyway i have a r56 n12 around 11k miles with a 2789 fault code (lean) and i was wondering if any techs on here have seen it before. some of the things i have done. checked the spark plugs and coils. no problem found. smoked the intake components. no problem found. smoked the vacuum pump. no problem found. smoked the brake booster (have had the same fault in a different car and it ended up being a cracked brake booster) no problem found. i would check the injectors and the timing but at 11k i dont think there will be a problem with them. any ideas?????

 

You check the vacuum block under the intake mani? I think it may be fed by the vaccum pump so you may be good. just another spot to check.

 

Check fuel filter.

 

might be O2 sensor related but I'd save that for last since it costs a lot

 

vacuum pump only supplies vacuum to the brake booster. (in a n14 it also supplies vacuum to the waste gate). i am working with a n12, but it is somehow connected to the engine. when i smoked it and opened the oil cap i saw the smoke come out of it. maybe i'll try replacing the vacuum pump. it did sound weird but was pulling good vacuum.

 

thanks for reply, i guess it could be blocking fuel but the vehicle only has 11k on it. and i have never replaced fuel filter on a n12

 

yea that was on the list of possible causes in the test plan. i guess ill pull it out and see if its burned up