Low Idle

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

     Hi Folks,
     
     My '87 5KCSTQ has had a problem for sometime now that my 
     independent mechanic can't fix.  When I start the car cold it 
     usually idles at 200 rpm instead of the normal 800 rpm.  
     Sometimes it starts and idles properly but the first time I come 
     to a stop, the idle drops back down to 200 rpm.  
     
     To get the idle back to 800 rpm I have to stop and start the car 
     6 or 7 times.  Then something magical happens and it idles OK.  I 
     replaced the idle stabilization valve but that did not help.  The 
     problem seems to be that the idle stabilization valve is not 
     getting any power.  When the low idle problem occurs the idle 
     stabilization valve is not buzzing or vibrating like it should 
     be. 
     
     My mechanic said it may be the computer but did not have a spare 
     computer to try since they run about $1,200.  Does anyone know 
     what sends power to the idle stabilization valve or have any 
     suggestions.
     
     Thanks,
     Chris