Well... it has had to happen once... and it did... this morning.
It was a very cold damp morning today... around 5°C. I was driving as usual to my job, normal spirited drive, engine was well warmed up. As ususal I floored it in 2nd gear at this one corner, which is allways fun. BUT! As the revs climbed up to the 4500rpm redline, I felt sudden decrease in acceleration, dashboard turned bright red with MCSF sign and when I looked behind me there was LOADS of black smoke, I couldnt see anything behind me (and I'm not kidding)...
My first thought was "this is going to be expensive", but then car didn't stop, or fell apart... It kept going, with the engine light on, actually it was accelerating better than before the MCFS...
When I parked in front of my job, I connected to the ECU with my laptop and read the errors.
This is what I got:
Failed Component Code: Air Mass Meter
Fault Symptom: Short Circuit Vbatt/5V
Warning Lamp Status: Warning Lamp Illuminated
Fault Code Storage State: Error Not Present at time of request
Event Count: 40 count
Environmental Condition One: Engine Speed: 4305,99 rpm
Environmental Condition Two: Fuel Quantity: 70,9 mm3/str
Environmental Condition Three: Accelerator Pedal: 100 %
Environmental Condition Four: Rail Pressure: 1623,5 Bar
Environmental Condition Five: Turbo Pressure: 2388,3 mBar
Environmental Condition Six: Engine Temperature: 86,4 °C
Now. It gets even more complicated. This weekend I was doing some tests with Alfadiag. To record some sensor readings from my car before I swap air intake and FMIC.
I noticed that "Measured AirMass" and "Target AirMass" were very different. Target was around 1200mg/stroke, and measured was around 1750mg/stroke
The MAF is practically new, I replaced it one month ago, becaue old MAF was reporting wrong Intake Air temperatures (it was constant 40°C no matter what the weather was outside...)
This one reports correct temperatures, but when I looked at some older sensor recording to compare old and new MAFs I now see that old MAF was reporting more "sensible" airmass data. Around ~1180mg/stroke max air flow (compared to 1200 target).
I guess the new MAF is a bit optimistic with the airflow figures. Should I get it replaced or is there something else to blame? Like a bad ground?