High idle problem on 87 5kcstq (2500-2800 rpm)

[Bill Rowe]

Could be the throttle switch

-----Original Message-----
From: quattro-admin at audifans.com [mailto:quattro-admin at audifans.com] On
Behalf Of blarson at zeiss.com
Sent: Wednesday, November 21, 2001 3:51 PM
To: quattro at audifans.com
Subject: High idle problem on 87 5kcstq (2500-2800 rpm)



I have been experiencing a very high idle on my 1987 5kcstq lately.  The
idle
occasionally is normal, but usually is up around 2500-2800 rpm.  I have
swapped
out the idle air bypass valve on the intake manifold with a known good
one, and
the temperature senders on the coolant neck both measure the correct
resistance,
and have no corrosion on them.  If the idle air bypass valve is
unplugged, the
idle drops to normal.
Has anyone else had this problem with another component other than these
two?  I
searched the archives, and these seemed like the most likely culprits.
Your
help is greatly appreciated.
Thanks,
Brian