Under the hood there are 3 coils, mark the 2 plug wires on one of them so YOU know exactly where they go on that coil. Now the next time it stalls those same 2 wires can be removed to see if fire jumps between the 2 plug wire terminals that the wires were removed from! This will eliminate the ignition system altogether!!! However there is a catch, it really takes two people to pull this off, one cranking the engine and one watching for fire. If it has ignition fire all that is left is a fuel system problem!! Which could possibly be the maf sensor. Another test: with engine @ operating temp and at idle, tap the maf sensor with a screwdriver handle, if the engine responds AT ALL, the sensor is most likely failing!!! If this doesn't help, take it to the shop for a scan test and repair.
The crank sensors is a typical problem for that. I would start there. You could check for spark when it wont start and if it has spark that eliminates the crank sensor. I have had a few that it ended up being the temperature sensor. When it wouldn't start we unplugged the temp sensor and then it would start. Most of the time that is on cold starts, but I have had a few that were when it was warmed up.
If it has spark the only thing left is a fuel related problem. Forget about 'anything' to do with ignition system!!!. Crank sensor, ignition module, ignition switch, shorted ignition wiring harness etc....... That is the only way to approach this one. It just narrows it down so much more quickly than unpluging multiple componets.
Sounds like the perfect approach thank you!
Oh I agree 100% with the other answers make no mistake about it, we each have our own way of testing and with all of this info you should hit it pretty close!! One way or the other. The object here is car repair only! What ever it takes! Every "tech" here could fix most any one of the problems posted IF we had the vehicles! However, we can only guess at it together on the net! Sure we are going to disagree, so do most other PROFESSIONALS! By golly.