Date:         Sat, 24 Sep 2005 18:29:36 -0400
Reply-To:     rkoller@HELIX.NIH.GOV
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Rick Koller <rkoller@HELIX.NIH.GOV>
Subject:      Stumble/stall/high idle '91 carat
Content-Type: text/plain;charset=iso-8859-1

Greetings All,
    I have been struggling with diagnosing a high idle/stumble/stalling
problem all day today..
Situation: '91 carat automatic, the idle is stuck at about 1300-1500 rpms 
no change from cold to hot engine.
recent plugs, cap, rotor. Van was running normally. Then suddenly lack of
power, along with stumbling/stalling and high idle when not moving. Van
can be driven but at a gradual pace, any heavy gas pedal application
results in above symptons.
What have I done:
I have spare working fuel injection components and in the attempt to fix
the van quickly, I switched potential trouble parts
temp sensor II (new),
idle control module ( tried several that I have including one off my other
working van)
idle control valve ( again several )
throttle position switch, ( cleaned and adjusted the backup that I know
works )
switched ECU's
switched AFM's
unplugged O2 sensor when the van engine was cold or warm no difference in
the idle
checked Hall sensor voltage and it was right at specs ( 5 volts )
Checked timing and it was in specs 40 degrees BFTDC @ 3000 rpms
Van starts right up when cold, had some trouble initially restarting it
when it was hot but this seems to have stopped.
Any ideas out there? Bad ground somewhere perhaps, don't seem to hear any
vacuum leaks, have pulled off varios vacuum lines. The one from the fuel
pressur regulator had some effect of raising rpms.
Thanks
Rick Koller