jordan
i have a 71 ghia convertable.  It starts and idles fine. when you start driving and applie the brakes to stop the engine will stall. if you are sitting still and apply the brakes the engine will not stall. this only happens when you are moving and apply the brakes. if you coast to a stop the engine will not stall.

    Im stumped by this problem please help.
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MY72BUG
Are you running an all stock engine, presumably a 1600 with a PICT carb?  If it is coming down from a higher RPM, as you are driving,  I might suspect that the electromagnetic idle shut off on the carburetor is not working after the throttle plate closes completely.  If you are just sitting still and the throttle plate manages to hang up a bit, it could keep running.  It sounds like carburetor related problems.  When was the last time the carb was rebuilt?
I'd rather have a partial bottle in front of me than a partial frontal lobotomy.
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olspeed
It could be the start of a cool or cold weather problem also. My Ghia doesn't see the roads after the first snow,but my bug is a different story. Does it run good at first and then the problem start to come on after a while or is this problem there all the time. If it's there all the time it is most likely the carb. If it comes on after driving for a while and you live in a cool climate I think you will find the problem is no carb heat.
Olspeed
66 Ghia 76 std Beetle
It's not a car it's a VolksWagon
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jordan

the engine is stock. the carburator has not been rebuilt in manny years. I did notice that there is a small solinoid at the base of the carburator. Should i disconnect it and see if the problem goes away. Also the distributor has a vacumme port on each side of the diaphram ,the inside port is disconected do you know if its supposed to go to ported vac or manifold vac. thank you for your help. 

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olspeed
On the solenoid that is on the carb. To check it leave the engine stoped but the key should be on, unplug the wire and then plug it back on. You should hear a click from the solenoid when it is working, if it makes no noise at all it is junk. On the dizzy the outside port is connected you say... it should be connected to a port that is right by the adjusting screws on the carb( sorry I don't have pictures) the one on the back should go to a port that is almost on the front of the carb,right by what looks to be a small softplug. And you should have both hooked up to be sure it is running right. Also you will have to adjust the carb,is it a pict 3 ? If it is we can walk you through the basics on that also.
Olspeed
66 Ghia 76 std Beetle
It's not a car it's a VolksWagon
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Wayne
Olspeed really knows his VWs!
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68autobug
jordan wrote:

the engine is stock. the carburetor has not been rebuilt in many years. I did notice that there is a small solinoid at the base of the carburator. Should i disconnect it and see if the problem goes away. Also the distributor has a vacumme port on each side of the diaphram ,the inside port is disconnected do you know if its supposed to go to ported vac or manifold vac. thank you for your help. 



Hi,
If You disconnect the  solenoid, You should not be able to start Your car as the fuel will be switched off.  You should also have an automatic choke on the RHS of Your carburetor..  If working correctly, this will choke the engine by cutting the flow of air when the engine is cold.  normally this shouldn't have anything to do with the stopping of Your engine when You stop..
Check all the wires in the engine bay to make sure they are all OK.
The problem is a strange one, as all beetles I have driven that stopped  when You stopped the car.. braked..  they did that at every intersection, and a good tuneup always fixed that problem.
As olspeed says, if that wire going to the fuel cutoff solenoid is loose or nearly broken off etc... it could cause that problem. also check the high tension lead going to the coil.. I did read of a case in the UK.. that the High tension [spark] lead from the coil to the center of the distributor cap was shorting out on something. Every time it was moved when being checked, it was OK again for a while.. but when that happened the engine stopped and stayed stopped.. until the wire was moved.
I take it Your engine will start again once its stopped???
You could replace all the ignition parts and maybe the carburetor and You could still have the problem... You can get many problems with vacuum ports and hoses and depending on what vacuum is at the port at that time, as the vacuum varies with the speed of the engine.
I believe the two ports You mentioned should be connected to a two vacuum can distributor - with Retard and advance cans.  and this may be the cause of Your rather UNIQUE problem...

best of luck

Lee in Australia

Lee Noonan
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68AutoBug - helping keep air cooled Volkswagens alive in Australia & around the World -

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ainokea
I was thinking Lee may be onto something when mentioning the vacuum can on the distributor. If the advance diaphram is faulty and the retard is not, when coming to a stop the retard unit could possibly be stalling the engine by pulling the rpm's lower than the carburetor can handle. check the can with a vacuum pump. If the pump holds vacuum, the diaphram is ok, if no, one problem solved. Last time I changed one of those dual vacuum cans the price was higher than an 09 distributor. That could be a consideration, an 09.
Ainokea 
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kd4zha
This is an old thread started years ago, but I don't see my answer to the problem.  I had the identical same problem on my '72 Ghia, and tried everything.  I couldn't figure it out, and I'm an ASE master mechanic and FAA licensed aircraft mechanic, and have been working on VW's since 1964 (that's all just so you know anybody can miss the obvious).  What it turned out to be is so rediculous I'm embarrased to say. 

The carburetor was loose!  I don't know how I missed it.  The rear mounting stud had stripped out of the carb's housing (but was still in place), and the front mounting nut was loose.  Sitting still, the carb would sit squarely on the gasket and seal properly (during all of my troubleshooting), but when BRAKING, only when braking, it would rock forward a fraction of an inch and break the seal, stalling the engine.

I felt so stupid!  Hope this solves somebody else's problems.
No matter where you go... there you are!
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Wayne
Funny how it can be something so simple...
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