Date:         Sun, 3 Aug 2008 15:40:01 -0700
Reply-To:     Mike Elliott <camping.elliott@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Mike Elliott <camping.elliott@GMAIL.COM>
Subject:      Heh -- I'm such a ninnyhammer
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

So Mrs Squirrel asked me to give her, and her bicycle a lift up to the
house from down at the local drugstore. So I decided to take the Vanagon,
and to disconnect the wire to the dash O2 meter, just in case the van's
weird idle/ECU thing is due to too much electrical interference on the O2
sensor wire. After all, VW ran a shielded wire from the ECU plug to the
splice to the O2 sensor, so maybe the long unshielded wire that I've run
to the meter is picking up and injecting interference into the O2 sensor's
signal wire.

So I unplug the feed to the meter, and start driving down the hill to pick
up Mrs Squirrel, and once the ECU goes closed-circuit, the engine runs
like total c#@p. I didn't think I'd make it to the store's parking lot,
much less back up the hill w/ Mrs Squirrel and her bicycle. The tank we
really close to empty, so I pulled into the gas station to fill the tank,
and paused.

Paused to consider whether disconnecting the dash meter could screw up the
engine that bad -- or whether the poor performance was the suspect ECU
acting up. Just to see if it made any difference, I popped the engine
cover and re-connected the inline push-on connector.

The engine ran far far far better. No problem making it home.

So I'm looking at the wiring diagram in Bentley's, thinking about the wire
shielding scheme, and wondering how the heck disconnecting the meter could
cause the engine to run so very badly.

Then, in a flash of blinding light (which very nearly knocked me to the
ground) the reason dawned upon me: I had disconnected the O2 sensor, not
the meter. Heh -- if ever I thought I was smart, this little experiment
suggests otherwise.

Oh, and no wonder that the dash O2 meter had been reading steadily in the
middle of the scale when it was supposedly disconnected.

But the good thing is: now I know what a Vanagon runs like when the O2
sensor is disconnected. Not very well at all. Nossir, it's pretty, pretty
poor.

--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
KG6RCR