2005 Passat 106,000 mi.
I just took a trip to NC from NY, 650 miles down on B100. I put a see thru pre-filter ahead of the factory fuel filter. Biodiesel typically cleans out stuff in the fuel system that lays there with the pump fuel. I changed it twice on the way down. The engine went into LOS (limp mode) several times, It would recover after a stop/start of the engine, and be fine for maybe 10 miles or 100 miles. It occurred at random times and set code P0299.
Milage was 34 MPG.
This is from the scanner log:
16683 - Boost Pressure Regulation: Control Range Not Reached
P0299 - 000 - -
Freeze Frame:
RPM: 2562 /min
Torque: 224.0 Nm
Speed: 70.0 km/h
Load: 49.8 %
Voltage: 13.53 V
Bin. Bits: 00001000
Absolute Pres.: 2427.6 mbar
Absolute Pres.: 1927.8 mbar
After filling up with pump fuel in NC the trip home was perfect. Never a flutter, and performance was excellent! Milage 39.1 MPG.
My biodiesel is good quality. I test every batch and wash/dry it thoroughly.
The engine processor has had chip modifications. I suspect the processor changes are optimum for pump fuel, but different settings would optimize it for biodiesel. I am trying a B50 blend now to compare results.
The ability to switch modes would be helpful as I will be running blends and straight pump fuel in cold weather.
I believe the modifications were done by Rocket Chip Red Lion, PA.
Does anyone have input that can help?
Thanks,
Bob Abbey
585-727-5100