Re: [T3] High Idle - Throttle Valve Switch Problems

["Shirleyclan" <shirleyclan@home.com>]

I would take a look at how the throttle position switch is hooked up, I
believe the 69 throttle position switch had four wires and the 72/73 had
five. The newer throttle position switch (5 wire) may not be compatible.
Take a look at the Bentley manual it shows the difference.
Jim S.
----- Original Message -----
From: "Jim Adney" <jadney@vwtype3.org>
To: <type3@vwtype3.org>
Sent: Thursday, August 02, 2001 12:56 PM
Subject: Re: [T3] High Idle - Throttle Valve Switch Problems


> On 2 Aug 2001, at 12:21, jim-a-lim wrote:
>
> > Hi all,
> >
> > My car's idle is still high.  I adjusted the throttle valve switch (a
few times, in case
> > I was wrong the first try) per the bentley manual to no avail.  Also,
the accelerator
> > cable is not stuck and the throttle valve is closed.  I then popped open
the switch to
> > make sure the contacts were clean (this had obviously been done before).
Is there any
> > way I can test the switch itself to make sure it is working?  It is a
5-connection switch
> > and, although my car is a 1969, and it is likely to be a 1972 engine.
>
> It sounds like everything has been changed to a 72 engine. You will
> have to just treat it as such. Does your distributor have both a
> vacuum advance and retard (vacuum can with 2 hoses?) If so then
> that is the 72 dist also. If your retard has stopped working then you
> will have a fast idle.
>
> You can check the vacuum units by sucking on a hose that you
> connect to it. With the engine off you should see the breaker plate
> in the dist rotate when you suck, or you should hear the idle speed
> change if you do this with the engine running. In either case you
> should not have to keep sucking, the can should hold vacuum.
>
> > I am curious, though.  in the literature section of vwtype3.org from the
Clymer manual,
> > it uses an ohmeter to (re) adjust the throttle valve switch.  It says to
'Connect an
> > ohmmeter (set to R x 10) across contacts on switch plug'.  Does that
mean I would connect
> > all 5 contacts to the Ohmeter?  I'm trying to nail down this problem so
that I can drive
> > the car.  This problem appeared out of nowhere and has been taking a
while to fix.  But I
> > guess I'm learning all about the FI parts in my engine.
>
> You need to find the section about adjusting the 72-3 throttle valve
> switch. For this, you will need to connect your meter across 2
> particular contacts on the switch, the ones that change state just
> off idle. Adjust the switch so that this contact changes state as
> soon as the throttle starts to move.
>
> In general, there's not much good to be said for the Clymer
> manuals.
>
> -
> Jim Adney
> jadney@vwtype3.org
> Madison, WI 53711-3054
> USA
>
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