my s10 tahoe?

The ignition module or the coil itself (I'm guessing because you gave no year or engine size) could be at fault. The last time I encountered this problem, it was the coil.

It could be the ignition module but if it starts right back up and runs good,I would say the fuel pump relay is bad. When you turn the key on, the relay is on as long as the engine is cranking or running AND the ECM is recieving distributor reference pulses. If there are no reference pulses from the dist. module, the ECM will turn the relay off after 2 seconds. The oil pressure switch will keep the pump running after it gets normal oil pressure. If the relay is bad and overheats before you have enough oil pressure for the oil pressure switch to take over, the engine will stall. If you then crank it again untill the oil pressure is high enough, the engine will run again. The oil pressure switch is a back up for the pump, when everything is working right, you can start the engine and remove the pump relay and the engine will still run. It will also start without the relay but you have to crank it longer ( until it has oil pressure) This doesn't eliminate the ECM or Dist. module. You still have to have a reference from the module on circuit 430( the purple and white wire from the distributor) to the ECM and the ECM has to be good.

Make sure you don't have some sort of alarm module. A lot of those cut off the engine after a few seconds of running. Some people don't even know they have them.

the oil pressure switch, the relay comes on when the key is in the start position and charges the fuel system, but when the truck starts and the key is released the oil pressure switch keeps the relay on, if the op switch is bad then it will die in a few seconds.

what year is it? It could be the module but most times either they are good or they are bad. Does it start back up when it dies?

Please give more information and perhaps I can help.