Vanagon EuroVan
Previous messageNext messagePrevious in topicNext in topicPrevious by same authorNext by same authorPrevious page (January 2002, week 3)Back to main VANAGON pageJoin or leave VANAGON (or change settings)ReplyPost a new messageSearchProportional fontNon-proportional font
Date:         Sun, 20 Jan 2002 17:20:53 -0500
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: Continued Bucking - Digifant readings
Comments: To: van man <vannman99@YAHOO.COM>
In-Reply-To:  <20020120215257.87402.qmail@web14914.mail.yahoo.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 04:52 PM 1/20/2002, van man wrote: >Throttle switch led and Fi led work correctly when >idling and wide open. >temp 1 - hovers around 1.24/5 up to 1.28 once

Air temp, seems reasonable.

>temp II - hovers around .14/5

Engine temp, seems reasonable.

>OX - fairly wild, occasional - to 6.3

Should be bouncing around, but never over a volt. If it's actually going to six volts, prolly a leak to the heater leads inside the sensor.

>AFM - around 3.5 - couple of checks showed 3.8/9

Should vary roughly linearly with throttle opening, up to somewhere near five volts. It actually reads the AFM position, so constant throttle with changing engine speed will give a changing reading, but you should be able to make it follow your foot short-term.

>When the bucking was occuring, numbers seemed to hold >steady, although FI light flicked on and off wildly.

That would certainly cause bucking...light should flash for each injector pulse, at running speeds looks continuous.

>Also, battery level down to low 11's during bucking, >even 10.9. still bucked a time or two at battery >level of 12+, but when bucking was bad, battery level >was always in the 11's.

Bingo. Bad ground somewhere, or possibly bad supply voltage to ECU. That voltage is what the ECU is seeing, not what the battery is delivering. Careful study of Bentley might show exactly which ground is the main candidate.

The main weakness (as well as one of the strengths) of the Digitool is that it depends on ECU ground for its ground reference. Bearing that in mind, you can use its external probe to look at various grounds. The *most negative* reading you find is the "best" ground. Ideally it should be very close (millivolts) to the negative battery terminal.

david

-- David Beierl - Providence, RI http://pws.prserv.net/synergy/Vanagon/ '84 Westy "Dutiful Passage" '85 GL "Poor Relation"


Back to: Top of message | Previous page | Main VANAGON page

Please note - During the past 17 years of operation, several gigabytes of Vanagon mail messages have been archived. Searching the entire collection will take up to five minutes to complete. Please be patient!


Return to the archives @ gerry.vanagon.com


The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.

Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.