Date: Sun, 20 Jan 2002 19:57:47 -0600
Reply-To: John Rodgers <jhrodgers@MINDSPRING.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <jhrodgers@MINDSPRING.COM>
Subject: Re: High Idle 1987 GL
Content-Type: text/plain; charset=us-ascii
Brad, while you are searching for a solution and trying to get your problem
fixed, may I suggest that you simply check your idle setting before you start
hunting all over the place and trying other things.
Do this by warming the engine, then jwith engine off, disconnect the Idle
Stabilizer Valve (ISV for short). It's the little cylinder like thing that sits
transversely right on top of the engine with the wire attach on the left end
when viewed looking from the the rear to the front of the van. Start your engine
and note the idle speed on the tach. It should be 850 to 900 rpm. If it is fast,
actuate the throttle momentarily and be sure it comes back to a solid seated or
closed position. It the idle is off, adjust it with the idle set screw. It is a
big slotted screw on the air intake system directly in front (towards the front
of the van) of the ISV. Once you have this set, with engine off, re-connect the
ISV and run the engine and check its performance. If things are flakey, then
move on to the next test as suggested by other list members. Many of my idle
speed problems have been related to the ISV. I started having a bucking problem
.... it was the ISV. Right now I am running with it disconnected. Not a problem
unless I need the air conditioner. I had a problem with the ISV control of the
rpms for operation of the air conditioner. The ISV system remps up the RPM to
prevent the AC from stalling the engine at low rpm. It was the ISV control
system causing me the problem. So needless to say, I always double check my idle
rpm setting, then look at the ISV when there is trouble. After that, I look at
other things. Process of elimination.
Good luck,
John Rodgers
88 GL Driver
brad barcom wrote:
> Hey everyone-
>
> I am new to this list-serve and am hoping someone else out there has had the
> exact same problem as I am having. It's been my experience that these vans
> tend to fail in the same way -- if only I would have known about this group
> when I was trying to solve the problem of my van cutting out at speed. Only
> by accident did I come up with the pigtail solution during a conversation
> with fellow Vanagon owner on trip through Boulder CO. Best $104 I ever
> spent on vacation.
>
> Anyway, I have searched the past 5 years of this serve and have found many
> good tips about how to address this problem. Now, however, I am stuck and
> need the advice of someone who has already traveled this road. Here is my
> problem:
>
> Like others, several years ago my 87 GL stopped idling in the 850 +/- 50
> range that Bentley suggests and started idling around 1200 RPM's during the
> colder months of the year. At that time, however, this did not seem like a
> big deal, so I just chose to live with it and drive on. Over time though,
> this problem has become more pronounced as my van goes through a perennial
> period of high idling (2000-3000), starting at the beginning of winter and
> ending with warmer weather in spring. During this winter engine racing, it
> also seems like my gas mileage goes down from around 20 MPG to 15-17. This
> may be due to the increased fuel usage at stops, but my intuition is that
> there is something else here at play. Also, the idle usually settles down
> to around 1,200 to 1,500 RPM's after the van has had time to thoroughly warm
> up -- although not always. During the warm months, the idle is much lower,
> although it never goes below 1200 RPM at any point in the year. Finally,
> after replacing the heads and a steering rack, I am ready to solve this
> problem once and for all.
>
> Per the advice of others on this serve and Bentley, I have checked the Idle
> Control Stabilizer Valve (ABV), cleaned it several times, but nothing seems
> to change. I have also checked the resistance of the temp sensor, but it to
> my dismay it was well within tolerances -- that would have been an easy
> thing to fix. A local mechanic told me that it was definitely the Idle
> Stabilizer Valve, but, when the van is racing, and I unplug this device the
> idle immediately drops down to normal, thus ruling out being "stuck"
> mechanically open. Also, when the van is racing, I can get it to stop and
> idle more normally by pinching off the air hose that leads to the Idle
> Control Stabilizer Valve for a couple of seconds. As long as I do nothing,
> the she idles fine. However, as soon as I touch the accelerator the van is
> once again off to the races until it reaches operating temperature, but even
> then it never idles normally. Right now, I am running with the ABV
> unplugged.
>
> I also removed the idle stabilizer control module from behind the passenger
> side tail light. Upon opening it up, I could see no visual burns as others
> in this group have noted, although it did smell oddly electrical in that
> cooked-board sort of way. However, I don't know if this really means
> anything, as that little bi-folded board has been stuck in that small casing
> for the last 15 years. I'd smell too if I were in there all that time.
>
> Anyway, my feeling is that this problem is electrical and not mechanical in
> nature, but I don't know where to go from this point. I am hoping that I've
> described some classic symptoms that someone else can immediately diagnose.
> I just know one of you out there knows exactly what I'm up against. Look
> forward to hearing from you...
>
> Gratefully,
>
> Brad Barcom
>
> 1987 Vanagon GL
> 1986 Toyota Truck
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