Date: Sat, 30 Dec 2006 21:16:19 -0600
Reply-To: Jerry <jbvelo@BELLSOUTH.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jerry <jbvelo@BELLSOUTH.NET>
Subject: Re: Failure to return to idle
In-Reply-To: <de48c0be0612301824m5363dda1o3fd63905a0b2d050@mail.gmail.com>
Content-Type: text/plain; charset="US-ASCII"
The easiest way to determine between a linkage/cable
problem is to isolate or remove the cable from the
throttle valve at the throttle body linkage on the engine. With
the cable disconnected you should be able to find out
where your problem is. Make sure your throttle valve works freely
with the cable disconnected. Do you have cruise control??
You could have a problem with the cruise control actuating cable.
If all is ok in the rear then the problem is forward of the
engine compartment.
I guess you probably know that
the Vanagon uses an entirely separate idle circuit comprised
of 1. Idle solenoid 2. Throttle position switch 3. Idle control Relay
(mounted behind the R/R tail light.
Typical tests to see if the Idle solenoid is working is to
listen/feel for vibration from the idle solenoid with ignition
key in RUN position. If you hear or feel it vibrating more than
likely it is good.
I can tell you by experience that a very common problem is
wear within the "throttle position switch". This mounts on the bottom
of the throttle valve body and should have a plastic cover
concealing the micro switch. It's very important that this switch
operates correctly and the adjustment is very sensitive. The throttle
position switch costs around $65.00. Always check for good ground
connections in the engine compartment.
Haven't experienced much trouble from the Idle Control Relay.
It's an expensive item to replace (appx. $250.00)
The Vanagon idle screw is preset and has a locking patch on it.
You really shouldn't have to adjust it unless someone has tampered
with it before.
GOOD LUCK!
Jerry
88 GL BUS-ter
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
mordo
Sent: Saturday, December 30, 2006 8:24 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Failure to return to idle
I have a not-so-much-annoying-but still puzzling issue with my 90 Carat,
2.1l wbx with AT:
It generally idles a bit high - at about 1000rpm. I haven't gotten around to
adjusting it down. But, when I put the trans in neutral or in park, the
engine is turning at about1600-1700 rpm. If I tap the accelerator pedal, it
will drop back down to its typical 1k rpm idle. When I come to a stop at a
light or stop sign, the engine pushes hard against the brake and the idle
holds at about 1100 rpm.
The pedal requires above-average pressure to hold speed while highway
cruising but does not otherwise seem unreasonably stiff for a linkage that
runs such a long distance. I've never driven another Vanagon enough to know
what normal feels like.
Engine idles and runs well, good acceleration, easy cold start, easy hot
start.
So, do we think the problem lies with the mechanical linkage anywhere from
pedal to throttle body or do we think vacuum-related or do we think
something else entirely?
--
mordo
1990 Carat