Date: Sun, 10 Mar 2013 14:18:16 -0700
Reply-To: Robert Keezer <warmerwagen@YAHOO.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Robert Keezer <warmerwagen@YAHOO.COM>
Subject: Re: Throttle stop switch? Stumbles on resume throttle..
In-Reply-To: <CAHTkEuLF2dtr9TyG=KEd=pEqTb6Ds7w+wrtU9Qfudh4NypLA4A@mail.gmail.com>
Content-Type: text/plain; charset=iso-8859-1
Don, as you may know, the throttle switch , actually 2 switches, is called the wide-open throttle switch and the idle switch .
Wide -open tells the ECU the throttle is fully open and idle tells it that it's closed.
When going down hill at road speeds, your foot is off the gas on steep hills and the injectors are off until. engine rpm drops to about 1200 rpm.
That means that the engine is not running during this time
The pop may be from a leaky injector not fully closing and leaking gas .
Just like the WBX engine, the throttle switches need to be checked for adjustment periodically.
Should read zero Ohms at closed throttle, infinite ohms as the throttle opens, and zero Ohms again at full throttle.
You should hear a click just as you open the throttle. You adjust by moving he switch forward or back on the plate after loosening the set screw.
Robert
1982 Westfalia
--- On Sun, 3/10/13, Don Hanson <dhanson928@GMAIL.COM> wrote:
From: Don Hanson <dhanson928@GMAIL.COM>
Subject: Throttle stop switch? Stumbles on resume throttle..
To: vanagon@GERRY.VANAGON.COM
Date: Sunday, March 10, 2013, 6:44 AM
I have a Digifant ignition on a 93 Jetta inline gas powered van.. When
I coast down a long grade at higher RPMs (highway speeds) there is often a
slight hesitation as I resume pushing on the gas pedal...This hesitation
can be more pronounced at high altitude, I think. Recently, at over 8000'
elevation I felt an almost "engine off" delay of perhaps a full second when
I reached the bottom of a slope and put my foot back on the pedal. If I
keep a very slight amount of throttle open, there is no hesitation.
Another diagnostic symptom (could be exacerbated by a small crack in my
exhaust downpipe) is that rarely, my exhaust will "Pop!" loudly a single
time when I drop throttle at lower rpms. This 'delayed throttle response'
was particularly un-nerving as I was descending a very slick and windy
snow-covered pass recently..."exciting moments" as the engine resumed drive
after descending slowly in a lower gear...
I have a switch that looks somewhat thin and flat, with a
leaf-spring/bent lever looking prong that is activated by a small post in
the linkage near my throttle body. I assume that is the throttle stop
switch. It seems to activate (mechanically) properly...it "click" when
you just crack the throttle and 're-clicks' when you release the throttle...
I can't decipher my 2 Bentlys (Vanagon and Cabriolet) well enough to even
figure out which switch I have and how to go about testing it. There
seems to be a couple of very different ones used on various Digifant
systems. Can someone guide me as to how to test this part? Does anyone
have any other ideas as to what might be causing this somewhat troublesome
delayed throttle response?
Don Hanson
