Date:         Wed, 6 Nov 2002 21:52:47 EST
Reply-To:     Rogerspace2@AOL.COM
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Roger Reynolds <Rogerspace2@AOL.COM>
Subject:      ISV questions (updates and clarifications)
Content-Type: text/plain; charset="US-ASCII"

Hi all,

I have been trying to track down a high idle situation for some time now and
still have had no luck.

The problem is a high idle (around 2000) that starts a couple of minutes
after start up.  If I disconnect the ISV connector, even briefly, while the
engine is running at high idle, the idle will drop down to 900 RPMs and stay
there for as long as the engine is
running.  If I restart with the ISV connected, the idle returns to 2000.  The
idle will kick up to 2400 when I turn on the AC and return to 2000 when I
turn it off.  I have also noticed that the engine will often stall soon after
it is started (it idles lowish (800-900) right after start up).

Update:  The idle was not kicking up when I turned the steering wheel all the
way to one side so I jumpered the wires leading to the power steering
pressure switch and the RPMs did kick up from 2000 to 2400 so I'll replace
the power steering switch.  That could be why it has been stalling in the
mornings (as I'm backing up and turning) before the high idle starts.

According to Bentley, the ISV should "vibrate and hum" when the ignition is
switched on.  My valve will vibrate and hum for about three seconds after the
switch is turned on (without starting engine) then stop.  I have noticed that
when the engine stalls and I'm at the engine compartment, I can hear the ISV
hum for a few seconds then stop.  When the engine is running at 2000 RPMs, I
can't tell if the ISV is humming or not because of all of the engine noise.

Bentley says the resistance across the ISV should be: continuity, mine is 4.5
ohms.  Is this good enough?

I have performed all of the tests, that Bentley lists, at the ECU connector
and everything is within specs given.  Have replaced: the idle stabilizer
control unit, temp II sensor, spark plugs, plug wires, and O2 sensor.  I have
also: cleaned the AFM, measured AFM resistance values, looked for vacuum
leaks, cleaned the grounds to the
left inside the engine compartment, adjusted the idle setting, and checked
the throttle position switch.

Update: When I pull the yellow  idle stabilizer control valve connector (that
is located sort of above the thermostat housing) apart the idle drops to
around 1000 RPMs.  The thing that doesn't make sense to me though is that I
can't get a current value at all (0 mA) when I connect my DMM in series
between the terminals of this connector.  I was expecting to get 420 mA.
But, when the DMM is connected to the two terminals, the RPMs surge back up
to 2000.  If I switch over to read voltage between the two terminals of the
connector, I get around 7vdc.
Looking at the Bently manual again though, I think it is saying that I have
to first remove the crankcase breather hose.  I'll try that and see what
happens.

Any advice would be greatly appreciated.

Roger