Thanks for the info. Frankly, I wasn't sure which way the system flowed. With your explanation, it makes sense to me now. BTW, thanks for your response a couple of days ago to my coolant leak problem. It was a heater hose leak. I just couldn't see it because it was located on the bottom side of the hose.
That's it -- the idle control valve. Thanks for your detailed explanation.
'92 Mercedes 190E/2.3 (247K miles/my daily driver)
'93 Volvo 940 Turbo Wagon (263K miles/a family truckster with spunk)
'99 Kawasaki Concours
'85 Jeep CJ-7 w/ Fisher plow (226K miles)'93 Volvo 940 Turbo Wagon
'53 Willys-Overland Pickup
'85 Honda 750F Interceptor
'93 Nissan Quest
'89 Toyota Camry Wagon
'89 Dodge Raider
'81 Honda CB 750F Super Sport
'88 Toyota Celica
'95 Toyota Tacoma
'74 Honda CB 550F