Date: Thu, 20 Jul 2000 09:04:45 EDT
Reply-To: JKrevnov@aol.com
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Rico Sapolich <JKrevnov@aol.com>
Subject: Re: Call to TOUGH Nut Crackers was- Digifant Idle & brief power
loss
Content-Type: text/plain; charset="ISO-8859-1"
In a message dated 7/19/00 6:42:03 PM, Doss88Wkndr@aol.com writes:
<< I have noticed my idle speed wavering between 1k & 2k, but it's just
annoying
- I really didn't think it was a problem ... but, just yesterday, while
driving on the highway about 50mph, I noticed a brief power loss. - not
enough to stall me - I just kept driving, and it went away, and ran fine for
about 3 hours after that. Today, sort of the same thing. It just lasts for 5
seconds or so, and there seems to be no way of predicting when it might
happen. I have a spare ECU, and thought I'd plug it in and see what happens.
Will a Digitool save the day, and make it fairly obvious what's happening, or
am I going to have to take it to a pro?
Brian Doss >>
Brian,
At this time I have no answers, just an anecdote which may indicate that we
have something in common.
I have been fussing around with the idle stabilizer control circuitry since
my idle stabilizer controller came up lame (high idle symptom). I replaced
it with a used one which cured my ills for about a month before the high idle
returned. I have since replaced the output transistor and 56 load resistor
in one of the defective controllers. This seems to have reined in the idle
... most of the time. I have not been able to get it to Idle as smoothly as
when I run it with the outputs from the Hall sender and O2 sensor
disconnected. I am running a Bus Depot O2 sensor with the necessarily
spliced lead. It may be coincidental but, rainy weather seems to provoke the
high idle.
I realize the foregoing may seem pointless but, history is paramount in
troubleshooting and I want you to know where I have been. Anyway, while
cruising at highway speed recently, I jammed the throttle to the floor in
order to prepare for a long grade. The engine died for a moment as if the
ignition had been switched off. The tach dropped to zero immediately. As
quickly as it happened, the engine caught fire again and the tach jumped back
to 4K. I was able to replicate this action at will by jamming down the
throttle. It ran normally when smoothly taking the throttle to the floor. I
reasoned that some errant bit of wiring was opening or going to ground when
the torque reaction of the engine shifted it on its mounts. When I pulled
over to check, I found the wiring in the forward left corner of the engine
bay to be rather loosely dressed. None of it was obviously shorted or
strained. Still, with the engine running off idle, I grabbed a hank of it
and tugged on it every which way I could. I only was able to cause the
engine to falter a little, but nothing like what I experienced at speed. I
dressed the wiring and went down the road with no more of the problem to
date. When I got home, I checked everything possible without finding any
detectable defects. I'll let you know when I find something conclusive.
As far as taking it to a pro: if you endure the rigors of troubleshooting
this yourself, YOU will be the pro.
Rich
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