Running super rich with black smoke
Hello All,
My DD (TI log)started to run super rich with black smoke out the pipe. Started a few days ago running rich but getting worse. Now looks like old school diesel!
Vacuum at -15" idle approx 900rpm.
1)Checked AIS appears to work. Yes the old style is a PITA.
2)leakdown on fuel rail is great... lots of pressure after the car sit for an hour.
3)FPR slight smell of fuel when vacuum nipple open but no liquid. the other vacuum lines slight fuel smell as well.
4)swapped MAP and doubled checked that baro solenoid was in correct position and not leaking with the car off (solenoid also off). car ran the same.
No codes shown
My thought is extra fuel is getting into the engine by a leak or the ECU is adding extra fuel due to a sensor issue
my action plan for lunchtime
1)ordered a new FPR just in case but a good idea to have a spare anyway.
2)check FPR with vacuum pump
3)check 02 sensor readback
4)check TPS
5)check VSS
6)check coolant sensor
other thought are welcome.
Re: Running super rich with black smoke
I'll assume the vacuum was checked via an actual gauge, and not a scan tool?... If via a scan tool, then I'd check the coolant sensor signal.
Two sensors have the biggest affect on fueling, the MAP (load sensor) and coolant (Temp/cold start). We used to trick the coolant sensor to add enough fuel for 100+HP worth of fuel by tricking the ECU via modifying the coolant sensor signal to say it's -20*F...
Good luck!
Mike
Re: Running super rich with black smoke
Quote:
Originally Posted by
zin
I'll assume the vacuum was checked via an actual gauge, and not a scan tool?... If via a scan tool, then I'd check the coolant sensor signal.
Two sensors have the biggest affect on fueling, the MAP (load sensor) and coolant (Temp/cold start). We used to trick the coolant sensor to add enough fuel for 100+HP worth of fuel by tricking the ECU via modifying the coolant sensor signal to say it's -20*F...
Good luck!
Mike
Thanks Mike,
The car is now running without black smoke.:)
I checked several items/line with vacuum pump (old fridge compressor with a gauge on both side on an isolation valve) and all components check out fine. I did built a new manifold with the NPT at the centre of the log as the orginal plastic one was frequently splitting open. This seems to happen when a M3 is close by...go figure. My PITA AIS was frozen 1/3 open, and I took a moment to free it up.
Thanks everyone for your thoughts
