Depends what you mean by "shutting off". If the ignition timing is severely retarded, the engine will run too slow and with too little power. That could lead to stalling when you approach a stop sign but it would not cause stalling while you were driving at a steady speed. If you have an intermittent electrical problem, typically that will cause sudden stalling regardless what speed you're driving at. That could be caused by the ignition module, ignition coil, or the pickup coil. Either way, you would have no spark right after it stalled. Check for spark right after it stalls. If it is there, don't crank it any more. Pop the air cleaner off, look down the air horn, and work the throttle by hand. Watch for two nice strong sprays of fuel. If you get none or just a few little dribbles, the carburetor is running out of gas. The symptom will be stalling with a little surging or sputtering before hand, not the sudden stall that electrical problems usually cause.
I'm more concerned with the high idle speed indicating a vacuum leak. I misread your first post and was thinking you replaced the carburetor. That's why I suggested the base plate gasket. Instead, look for a vacuum hose that is disconnected or cracked. One large one goes to the power brake booster. Try pinching off those hoses to see if the engine speed comes down.
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Monday, April 18th, 2011 AT 10:07 PM