sounds like fuel starvation to me too....how long does it rev up for before it farts and dies....???

it doesnt sound like crank sensor to me as my understnding is that generally (but not always i guess) you dont get fire up wwhen one goes bad....

when it starts can you hold it running by giving it a few revs? wondering if it could be the Idle Motor sticking....

first off i would do the obvious (new air filter, change the plugs, any leads, cahnge the fuel filter, clean out the throtle body, run a load of injector cleaner through it, check the engine earths, full and replace al lthe fuses to ensure good contacts, pul lthe relays and replace them for the same reason, clan the batttery terminals) see if it makes any difference...

btw does the gas level in the tank have an effect ?
also when it happens....try opening the gas tank filler, then putting it back....

in all likelyhood all the above will make NO difference, but its good maintenance and cheap DIY stuff to start with - my philospohy is eleiminate the easy cheap stuff first before spending money on the expensive stuff!