First, it�s not the tranny. I won�t go into why, trust me.
Second, The next time it happens pay attention to exactly under what conditions and what it feels like. Typically a spark related stall is just like turning off the key, no stumbles and such. A fuel related stall is more gradual more like a loss of engine power, the engine may kick or stumble on it�s way out. Next, see if it starts right back up or it takes a few minutes. If it starts right up it could be a bad electrical connection, if it takes some time, it could be fuel starvation (clogged filter, or week pump).
One more thing, Cell phones laptops CB radios car stereos and things like that can generate RFI and cause stalling. Did you add any aftermarket electronics lately?
jeff
