[cdziekan]

I have a 2011 e90 equipt with the n55 motor and after coming to a stop and putting the car in park the car it will sometimes have a odd idle pattern where the rpm bounces around a bit (~40-60 rpm variation) for about 30 seconds then goes back to normal nice and smooth idle.

here's a log you can see how at first the fuel rail pressure is around ~1700 psi with negative timing around -15 degrees, then after it randomly idling "rough" the fuel rail pressure drops to 700 and timing advances and idle smooths out.

PHP Code:

https://datazap.me/u/cdziekan/odd-idle-pattern-negative-ignition-timing-and-high-fuel-rail-pressure?log=0&data=4-16 


it only sometimes happens usually after driving the car hard. just wondering if this is normal or something is acting up.

any opinions is appreciated

[cdziekan]

I noticed that the o2 sensor voltage drops when the idle starts getting weird. You can see in the log drops from 1.7 to 1.1 ish when it’s iding bad

[cdziekan]

bump