Again, when it rains it pours!!...now bad throttle switch?

[Huw Powell]

> Just to add to the previous msg, on the VW QSW there
> are two swtiches on the throtle body, since it's
> CIS-E.

CIS and CIS-E3 have two, as well...

> According to a lister on the QSW the following
> applies:
> 
> The one (switch) on top is full throttle enrichment.
> Only needed normally in high rpm, high load, full
> throttle type situations.

Correct, activated any time you go past about 2/3 throttle.

> The one that's harder to see if the idle switch. Helps
> CIS-E start delivering gas again after you've been
> coasting in gear or coasting in neutral and RPM
> falls after you've shifted to N. Affects idle, too.

Uh... ok.  It is only activated at idle - foot off pedal - and tells the 
ECU to use the ISV to regulate the idle.  On E3, at least, I can't 
remember on E, its activation also throws a quick negative current to 
the CPR to cut the fuel you were using immediately since it won't be needed.

And, yes, it's hard to see, and work on, since it is mounted on the 
bottom of the throttle body.

> Both of these switches get beat up by exhaust heat.
> The idle one especially, I suspect. Later VW's had a
> heat shield under them so radiant heat from the
> exhaust didn't get them so directly.

Good point about the exhaust being hard on the idle switch.

> I ZIP-TIED THE THROTTLE SWITCH ON TOP of the throttle
> body.

As I said, disconnecting both of them makes more sense - and so does 
testing (and cleaning) the idle switch.  Just take a meter to the 
connector, you don't have to reach or see the idle switch to "work it", 
just use the TB pivot where the gas cable pulls on it.  In a quiet 
environment, you should even be able to hear it clicking as you move the 
TB slightly off idle and release it.

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/