Although I love driving my 86 GMC 1/2 ton up here in the beautiful Pacific Northwest, I must admit that from about mid November until about mid April, the mornings can be a little frustrating until the engine has completely warmed up. I'm convinced the problem is "Carburetor Icing" as my symptoms are exactly as decribed in this link and have focused my attention on the intake air heating. systemhttp://www.chevron.com/prodserv/fuels/bulletin/motorgas/gallery.asp?img=46 I've checked the vacum motor located in the air cleaner snorkel to make sure the flap works when vacum is applied, and even replaced the temp sensor (which controls the vacum to the motor) to no avail. However, when I start the engine cold and unplug the vacum hose (from the sensor to the vacum motor) there does not seem to be any vacum\suction coming from the sensor as it should. The temp sensor has two outlets with one hose connected to the vacum motor and the other hose connected to another part in the air cleaner housing called a "ported vacum switch" which I haven't yet replaced. Thanks in advance for any suggestions! Cheers
