Re: Urq Suddenly fast idle speed it's cold outside

["Wiggins, Rodney L" <rwiggins@clev.frb.org>]

     my 83 did this last winter. Very annoying. Vaccum leak almost 
     definately. Mine turned out to be in the mystery valve( it was 
     sticking open when warm, it was vacuum actuated to send exta meetered 
     air past the throttle)  which noone seemed to be able to 
     identify(early attempt at a bypass valve perhaps), and no it wasn't 
     the auxilary air valve. (long story) I removed the valve and the car 
     was fine. Anyway, there are several hoses coming off of a tee at the 
     back of ther intake manifold. you should be able to systematically 
     pinch off each of these (engine running, high idle) and find out where 
     your problem is. This is an excellent oportunity to findout where each 
     of those hoses go and what their purpose and condition are. If this 
     fails try spraing carb-cleaner around suspected bad connections. When 
     the leaking vacuum pulls in the carb cleaner the idle will drop. You 
     will have found your leak. This really does not sound like a mixture 
     problem. 
     Hope this helps,
     Rod Wiggins
     
     
______________________________ Reply Separator _________________________________
Subject: Urq Suddenly fast idle speed it's cold outside
Author:  R1chT@aol.com at SMTP01
Date:    1/5/96 10:04 AM
     
     
After driving home last night, my idle speed is now about 2000 rpm after 
warmup to 190 F as measured in coolant reservoir,  duty cycle measures 68 to 
75 % on fluke DMM note this may be inverted from the way it's measured on 
other meters. so it could be 25 to 32 % I forget which way is richer. Haven't 
tried to change idle mix, I don't have my 3mm allen wrench (was stolen). My 
thought is possible  ice on the airsensor. What about a vacuum leak? or other 
possibilities. Currently about 0F outside. This is your puzzle for the day. 
Thanks for your comments. 
     
-Rich 
Concord NH
'83 TQC