A few years ago I had a simular problem. I would start the engine and when I would start going it would stop. It done it about three times. To me it was like if somebody was shutting the ignition switch off. So I took the ignition switch off and noticed that the back side of the switch was kind of expanded out and was not making good contact. I got a piece of wire and wrapped it around the switch and tightened it up to bring the back cover into place and apparently that was the problem, because I have never had that happen again. And I was going to replace the switch, but since it has not given anymore problems I just left it as is. It has been now at least five years with no problems. So like they say, if it is not giving problems, leave it alone.