Idle surging up and down

[danws69@earthlink.net (Dan)]

I had the EXACT same problem and symptoms with my 16v recently.....


here's what I did:
a) take off the air boot from he air cleaner to the intake....clean
thoroughly
b) clean the TB thoroughly
c) take the idle screw all the way out and clean that opening thoroughly
d) check to make sure that the throttle-thingie (can't remember what it is
actually called) is contacting and engaging the idle switch
e) when you put the idle screw back in, make sure the rubber o-ring isn't
shot, if it is, use something (I used that black silicone stuff) and then
screw it back in....NOT TOO FAR THOUGH! Start the car, the idle should be
REALLY high, that's a good thing, start screwing the idle screw into the TB
until it reaches ~1100rpm

Have fun!

Dan
Tam-pa, FL
'87 16v Scirocco
'81 Rabbit Sportruck
'00 Jetta
http://home.earthlink.net/~danws69/index.html
-----Original Message-----
From: scirocco-l-admin@scirocco.org [mailto:scirocco-l-admin@scirocco.org]On
Behalf Of Andy Morris
Sent: Wednesday, March 27, 2002 13:28
To: Volkswagen
Subject: Idle surging up and down


I have an 85 Scirocco 8v with 296,000 miles on it.  Yesterday it started
idling kind of low so I suspected a vacuum leak right off the bat.  I used
an entire can of carb cleaner looking for the problem and could not come up
with anything.  Now the engine is going from "almost stall" to 1100 rps - up
and down.  It sounds like the vacuum booster is saving it, at the last
second, from cutting off completely (I can hear it click just before it
dies).  The car idles perfect if I turn the A/C on and the compressor is
running; like the A/C vacuum booster is keeping it idle.  I know it is not
the boosters because I swapped it out from my parts car just to check.  Any
ideas?

Thanks!
Andy Morris
jeepvolks@alaweb.com