Date:         Tue, 16 Sep 1997 16:58:20 -0700
Reply-To:     "Justin B. Jensen" <jjensen@SPRINTMAIL.COM>
Sender:       Vanagon mailing list <Vanagon@Gerry.SDSC.EDU>
From:         "Justin B. Jensen" <jjensen@SPRINTMAIL.COM>
Organization: The MAXIM Group
Subject:      Re: Surging at Idle (2.1 Digifant)
Comments: To: Lawrence Johnson <ljohnson@HALHINET.ON.CA>
Content-Type: text/plain; charset=us-ascii

Lawrence Johnson wrote:
>
> On the principle that there is no such thing as a stupid question:
>
> When I first start the engine, the revs first go to about 1500 rpm and
> then promptly drop to about 1000 rpm where it begins surging between 950
> rpm and 1050 rpm on about one second intervals. After the engine warms
> up, the idle settles down to a respectable 950.
>
> What causes the surging?
> Is there a simple explanation/cure?
> Is it anything to concern myself about?
>
> Larry
> '86 Syncro Westfalia
Larry,
You should find your trouble in one of the following:
1.  Check the adjustment and operation of the throttle switches, namely
the throttle-closed switch. While you are at the throttle body, check
for excessive "slop" in the throttle shaft due to worn bushings;  these
parts are known for wearing out, resulting in an uncontrollable idle.

2.  Check for a vacuum leak.  Be sure and look for a split in the
underside of the boot connecting the air flow meter to the throttle
body.

Good luck.