Jack, I found this interesting reference to carb icing. Sound just like what I've observed other than i didn't feel the inlet under the carb last nite to see if it was very cool.
"Someone wrote to say that his '73 Super with a 1600cc engine runs just fine around town, fine getting on the highway, fine on the highway, but as soon as I slow down, i.e., get off the interstate, engage the clutch, she stalls out on me. I usually pop the clutch and get her running again. Most of the time though, she won't even idle after I get off the highway. It usually takes a few minutes for her to be back to normal. I've tried adjusting the carburetor (Solex 34PICT), and adjusting the timing (009 distributor), to no avail. Am I just not adjusting it correctly? Rob responded - Sounds like manifold icing. Even in warm weather, if the riser tubes that heat the manifold are blocked, you'll get ice in the inlet, due to venturi effect (the mixture is forced into a smaller tube, it moves faster and cools the inlet). You really need to take off you muffler, and try to clean out the riser tubes. Easy to check: when it acts like it wants to stall, feel the inlet under the carb. If its frosty, or really cold, you have blocked risers. (This is only really relevant to the Bug that has run on the highway for a while.) Also, check to make sure the heat risers are hot to the touch (careful - the right one may be VERY hot). If they are not, you may have an aftermarket muffler or header with heat riser flanges that are not drilled through into the header/muffler pipe. See our discussion of this situation above." We'll see. Mike In Christ and Christ alone, MIKE MOREHOUSE "Therefore, if anyone is in Christ, he is a new creation; old things have passed away; behold, all things have become new." 2nd Corinthians 5:17 --- On Fri, 1/23/09, Jack Dinan <[email protected]> wrote: > From: Jack Dinan <[email protected]> > Subject: Re: [vintagvw] Dies at Idle Problem Comes Again > To: [email protected], "Air-Cooled Volkswagen Discussion List" > <[email protected]> > Date: Friday, January 23, 2009, 6:35 AM > Mike: Don't overlook the possibility of icing caused by > strange weather conditions and a heat riser tube that is > clogged with carbon. > jack _______________________________________________ vintagvw site list [email protected] http://lists.sjsu.edu/mailman/listinfo/vintagvw
