Date:         Fri, 14 Aug 1998 13:32:53 -0400
Reply-To:     Kay O Fremgen <kayfremgen@JUNO.COM>
Sender:       Vanagon Mailing List <Vanagon@vanagon.com>
From:         Kay O Fremgen <kayfremgen@JUNO.COM>
Subject:      87 Vanagon hesitation chapter (3)
Comments: To: Vanagon@vanagon.com

Hi again,

Darrell thank you very much for still hanging in there with me, and also
to Bill and Mark for participating in Chapter 3.  Hate to disappoint you
guys but I'm a Male, first name is spelled Kay ( thanks to a German
grandma) but it's pronounced as Kai.
Lets see if I can get everyone brought up to date.
With O2 sensor connected I have hesitation under load more sever with AC
compressor on.
With O2 Sensor disconnected the van accelerates just fine.

87.2 Westy automatic
VIN # WV2ZB0254HH079343
MOTOR# MV 029505*

Air flow meter: OK
Fi temperature sensor: OK
Throttle switch: OK
Fuel Pressure: OK
Exhaust leaks: None
O2 sensor: OK (have exchanged the sensor 5 days ago with no improvement)

Observations:
The old and new O2 sensor when connected to ECU are giving me up to
"negative" 0.1 volts for about 3 to 4 seconds under load  (AC compressor
on).  Which is approximately the duration of the hesitation.
During deceleration above 1250 rpm (fuel gets cut off to the injectors)
my volt meter is showing me "negative" 0.05 volts with AC compressor off,
and "negative" 0.1 volts with AC compressor engaged.

Darrell you wrote:
" My 86 has 0.5 volts on the ECU end of the wire with just key on or when
running and the sensor disconnected" my wire reads 0.06 volts. (isn't pin
#2 looking for an incoming signal from the sensor?  Why is it sending
voltage?  Could this be my problem?)
You also wrote: "Does your Bosch have the 022D or just 022", my data on
the sticker that is attached to the computer reads as follows:

                                  Bosch
                                  0 261 200 065
                                                                    (810)
                                  DF     VW  025 906 022

You wrote: "Does it only happen coming off idle?" No.  It happens off
idle 3 to 5 seconds of hesitation, 1500 rpm and up: 2 to 3 seconds
hesitation, 1800 rpm and up: 1 to 1.5 seconds hesitation, 2000 rpm and
up: starts becoming unnoticeable.

Which leaves us with:
Why the "negative" voltage from the O2 sensor?
The coax wire (green) connected to ECU and the O2 sensor disconnected,
reads 0.06 volts versus 0.5 volts (which is the number you are giving me)
with engine running.
By observing the O2 sensor hooked up to the ECU with the volt meter, why
does it take the computer so long to bring the fuel mixture back up to
0.5 volts?  (this sometimes takes up to 6 seconds)

Open to any suggestions, if you need me to measure anything just holler.

Thank you,
Kai








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