98 A4 starting issues and codes

[Mark Rosenkrantz]

The 18010 is anytime the ECU looses power (battery terminal pull, dead
battery, etc.) and is likely nothing.

I'd start with resetting the throttle body alignment and then doing some
logging of the fuel trim and timing while driving.  Also, take a look at the
g/s of airflow from the Mass Airflow Sensor.

The EVAP system has a full test using VAG-COM.  Well, for the full test, you
need a smoke machine.  If the leak is truly large, that could be the
problem.  Or it could be a loose cap.

The system too lean is likely the issue... but why is fuel being cut on both
banks?  Massive air leak of un-metered air (most likely), bad fuel caused
clogged injectors, clogged fuel filter, bad pump or check valve, etc.  I'd
do the key on and residual fuel pressure tests to check that end.  Generally
a fuel filter issues are manifested by steady state turns at moderate
speeds... not at idle/start.  After you verify the pressure, you might want
to do a volume/spray pattern test.
Also, I read that link... the N80 valve make some sense as well.

Hope this helps,
Mark Rosenkrantz
On Sat, Jan 15, 2011 at 5:24 PM, <dgraber460 at aol.com> wrote:

> 5 Faults Found:
>
> 18010 - Power Supply Terminal 30: Voltage too Low
>        P1602 - 35-10 -  -  - Intermittent
> 17546 - Fuel Trim: Bank 2 (Add): System too Lean
>        P1138 - 35-00 -  -
> 17544 - Fuel Trim: Bank 1 (Add): System too Lean
>        P1136 - 35-00 -  -
> 16839 - EVAP System: Large Leak Detected
>        P0455 - 35-00 -  -
> 16825 - EVAP Emission Control Sys: Incorrect Flow
>        P0441 - 35-00 -  -
>
>