Date:         Fri, 31 May 2002 14:07:37 -0700
Reply-To:     Keith Hughes <keithahughes@QWEST.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Keith Hughes <keithahughes@QWEST.NET>
Subject:      Tiico / Vagcom / Mileage - Kinda long
Content-Type: text/plain; charset=iso-8859-1

Fellow Tiico Nuts,

I have an '86 Westy with a Tiico conversion (about 4K on the engine
now) and I've been fighting with low gas mileage. Currently I get
about 18-19 mpg (65 mph freeway, unloaded, just me in it) up to
about 21mpg (40-50 mph back roads). Mileage was a lot worse, but
while on a trip, I replaced the O2 sensor with a generic 3-wire
(all I could find), and picked up about 3mpg.

I bought the VagCom software to interface/trouble shoot this puppy
and here's what I've seen:

Initially, (after O2 sensor replacement and error codes cleared)
had the following DTC's:

00561 Fuel Mixture Adjustment
        14-10 Adaptation Limit (add) Exceed - Intermitent

00525 O2 Sensor (G39)
        03-10 No-Signal - Intermittent

At this point, I reset everything (timing - 10°BTDC, CO, Basic
setting), and redid the O2 sensor connections (crimped & soldered).
Also traced down all the O2 sensor wires from plug to ECU, and all
check out OK. At Peter's suggestion, I pulled the MAP sensor and
cleaned it, and it appears to work fine.

Since then, I've gotten the following DTC's:

01247 Evap Canister Purge Regulator Valve (N80)
        37-00 Faulty

00561 Fuel Mixture Adjustment
        12-10 Adaptation Limit (mul) Exceed - Intermitent

00537 O2 Sensor Regulation
        27-00 Implausible Signal

        (This second one is the only one I've seen in the last 200 miles
or so.)

Anyone have any suggestions?

Also, using the VagCom, I've tried to make sense out of the Group
00 numbers, and some of them seem reasonable (engine load, coolant
temp [in °F however], RPM [needs a X10 multiplier]) but some make
no sense at all. Like for instance, position #2 is supposed to be
battery voltage, and my reading is "184". A snapshot of my Group 00
readings is:

1       2       3       4       5       6       7       8       9       10
152     184     212     029     128     133     002     009     009     091

Are these numbers comparable to what you folks have been seeing?
Any help/suggestions appreciated. Thanks,

Keith Hughes