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Tue Nov 16, 2004 4:11 pm

I have a bone stock 1600 in my '73 Super. My problem is this: After the choke opens and the idle steps down, the motor won't stay running unless I give it gas. The idle just falls away and the motor dies (when coming to a stop, for instance). It will do this for the first 10 miles of running, long after I start getting heat in the car. Its right around or above 32 degrees when I leave for work. The car sits in a detached garage overnight however. The day warms up to around 50 but gets pretty cold by the time I head back home. Oddly enough, the car doesn't do it on the evening ride home. Any ideas? My thoughts lead me to believe the mixture is just cold enough in the morning to be falling out of atomization. I've always driven carb'd cars but the Beetle is the first with such long intake runners/tubes. Are my heater tubes carboned up? Any thoughts on the matter would help. Thanks.

Tue Nov 16, 2004 4:22 pm

Check for carb/manifold icing...if the preheat tube is clogged up, then it won't warm up properly.

Tue Nov 16, 2004 4:34 pm

What exactly does that mean? Look for what appears to be ice on the manifold and carb housings?

Wed Nov 17, 2004 6:00 am

Heater tubes arent made for 32 degree weather as much as 0 degree weather. The first thing i would do would be to give it a nice tune up if u havent in a while and try this:
Adjust your choke
Or this is common as well: On your carb (34 pict3?) look at the left side, there will be a smaller screw in a tube looking thing right below a much larger screw. This should never be tight its an adjustment screw. Try unscrewing this a quarter of a turn and see if this helps at all. This will richen up your mixture a little bit and give your engine more gas in the morning. If this works you should probably adjust your carberator sometime soon.

Wed Nov 17, 2004 6:48 am

Cobey wrote: What exactly does that mean? Look for what appears to be ice on the manifold and carb housings?
mostly I've seen it on the manifold right underneath the carb - a thin film of ice, maybe 1/16" to 1/8" thick. Looks like the layer of ice on the inside of a freezer...
That's where my old bus would always ice up in cold weather - especially cold, wet weather...

Wed Nov 17, 2004 8:57 am

With the engine running see if the heat riser pipes are pretty warm. I think it actually gets warmer on the drivers side first than the pass side for some reason. If you let it idle for about 5 minutes in your driveway, you can feel them warm right up. You really want those to work right.

Something to rule out if they are working.

Wed Nov 17, 2004 7:40 pm

I have tried several approaches to my morning routine. If I hop in and drive away, it does it for sure. If I let let it warm up for 5 minutes, it still does it. Today I tried letting her warm up for 10 or so minutes. It still did it, but the problem went away in half the time. I'll try feeling the heater tubes tomorrow to see if I getting heat up to the intake.

Wed Nov 17, 2004 7:45 pm

u try adjusting ur carb yet and makin it a tiny bit richer? Its very easy to do and make sure ur choke is at the top tooth when the car is totally cold

Thu Nov 18, 2004 4:03 pm

Well I checked out my heater tubes this morning. After exactly 7 minutes of warm up in the driveway, the right side of the tube was warm (but could still be touched) and the left was pretty much cold. Does this mean they're blocked? Also, Led Zep (best band ever btw), are you referring to the idle mixture screw? The left side of my carb only seems to have an idle speed screw.

Thu Nov 18, 2004 5:42 pm

what style carb do you have (model rather). And if only one heater tube being clogged up should make much if any of an empact in 30 degree weather, In fact some people take them off in NC wich i disagree with, they do help in the warm up process. You have to think these cars were designed in germany. It can get reallly cold in Europe. Another thing you might want to look into (although i think the carb should do it) is if you have vents/thermostat. A lot of people thought that these were useless and took their vents off their fan shround (A PO took mine off. If i start having troubles in January im going to get a "right" fan shroud. Just look under the passenger side of ur engine under the push rod tubes and see if there is an accordian shaped or a mexican thermometer (aircooled.net has a picture of both i believe). If you have this then you should have vents, If not than you most likeley do not have vents either.