

| Subject: | Re: AFM track cleaning wisdom |
| From: | Jake de Villiers |
| Date: | Thu, 12 Aug 2010 19:12:15 -0700 |
"Scottish Pounds"?! I don't think so... On Thu, Aug 12, 2010 at 8:51 AM, David Beierl <dbeierl@attglobal.net> wrote: > At 08:44 AM 8/12/2010 Thursday, Mike \"Rocket J Squirrel\" wrote: > >> Whaaaa..? >> >> Sez who? >> > > The term "Vanagon Syndrome" has been rather corrupted. The original > tech note from VW referred to a resonance effect under certain > conditions of steady throttle and load that could trigger an ECU > error mode. The fix was an active circuit inserted into the AFM line > that limited maximum rate-of-change of the AFM signal. > > This tech note was later extended to the 1.9l -- and indeed, I once > experienced the genuine article on a long straight road in Scotland > in '91, when my total mileage behind the wheel of a Vanagon was oh > say 500 or so. It was in the '84 Westy that later became Dutiful > Passage. A couple hundred miles earlier I'd experienced full-on 3-4 > synchro hub failure, so you can see I was richly blessed. And so I > was, with a sister (the then owner) who paid three thousand Scottish > pounds at the dealer for a transmission swap. > > After a while VW quit giving out the little harness for free and > started charging serious money for it, and some bright spark thought > "I bet a few microfarads in the right place would do the job just as > well," and so it was. > > But the law of unintended consequences came into play -- since either > device limited maximum rate of change of the signal, it would largely > cover up for little dropouts caused by track wear in the AFM. For > once this was a good thing. > > Thus saith the Lord. > > Yours, > David > -- Jake 1984 Vanagon GL 1.9 WBX 'The Grey Van' 1986 Westy Weekender/2.5 SOHC Suby 'Dixie' Crescent Beach, BC www.thebassspa.com www.crescentbeachguitar.com http://subyjake.googlepages.com/mydixiedarlin%27
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