Date:         Mon, 18 Apr 94 9:39:39 EDT
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         steriti@dragon.cpe.uml.edu (Ron Steriti)
Subject:      Re: engine surge on idle --- FIX

> 
> On Sat, 16 Apr 1994, Ron Steriti wrote:
> > I tracked it down to the idle temperature sensor.
> > Seems that it is a thermsistor that senses when the
> > engine is cold. I added a 500 ohm resistor in series
> > to it. Seems to have stopped the problem, although
> > the idle is a bit low (800 rpms).
> 
> Can you tell us what led you to add the resistor? 

The VW repair men said that they had replaced this sensor
and that it immediately blew (charged me anyway).
(so actually i didn't track anything down)

> Is there some electronic stuff here that you've actually figured out?

Not really.

> Why 500 ohms? 

The manual has a chart - "Temperature vs. Resistance"
at normal operating temps it indicated about 600 ohms,
so i figured i'd fool the computer into believing
that the van was already warmed up.

> Isn't that 500 ohms in addition to the resistance of the thermistor? 

Yes, in addition to. Didn't seem to work as well in parallel.
(i wondered about this too and did try rewiring it)

Joel reported
> that _replacing_ his temperature sensor improved his surging, but this is
> the first I've heard of the resistor solution.  Also, where did you mount
> the resistor?  Did you just solder the wire to it and tape it up and let
> it hang, or did you actually mount it somewhere? 

Taped it with the other wires.

ron