Poor cold start/idle

["CHRIS AHOLA" <aholact@songs.sce.com>]

     [snip]
My car has the idle stab. temp wire connected to a 1-wire 
temperature _sender_ which looks like and shows about the 
same resistance as the engine temp sender for the ECU. 
One of these senders is mounted on the upper coolant hose 
flange along with the turbo pump thermo switch and the 
multi-temp sender.  The other is mounted directly on the 
side of the head a bit forward of this flange - near the 
steering pump.  The Bentley seems to suggest that this 
forward mounted sender is the ECU temp source. On the 
other hand, the only coolant flange mounted 1-wire device 
the dealer shows is a sensor, not a switch.
     
     The thermoswitch mounted directly on the side of the head a bit 
     forward of the upper coolant hose flange - near the steering pump 
     controls the idle stabilization system.  To quickly determine if 
     this thermoswitch is bad, disconnect it and reconnect it to the 
     other thermoswitch near the upper coolant hose flange.  Then 
     start your car, if it runs OK you'll know it was a bad 
     thermoswitch.  I've been running my 5KCSTQ for two months with 
     the wire for the idle stabilization thermoswitch clipped to the 
     other thermoswitch on the upper coolant hose flange.  I just 
     haven't had time to replace the bad thermoswitch but everything 
     seems to run OK.
     
     
     [snip]
Questions: is the idle stab. temp input supposed to be a temp 
sender (variable resistance changes with temp) or a thermo 
switch (on/off)?  


     My Bentley calls it a thermoswitch and gives the following 
     spec's:
     
     up to 68 F  = 0 Ohms
     above 104 F = infinity Ohms
     if not, replace thermoswitch.
     
     
TIA
     
DeWitt Harrison              de@aztek.com 
Boulder, CO
88 5kcstq
     
     Good luck and I hope it is as simple as just a switch.
     
     Chris
     '87 5KCSTQ

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Subject: Poor cold start/idle
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