97' nissan pick-up started dying while driving air bag light came on then hesitating finally died thought it was battery . changed battery worked fine for two days then same thing . took alternator off took it to get checked alternator passed check reinstalled alternator jumped and drove one day seemed ok then same thing started again.cleaned and checked all electrical connections, tightened alt. belt. still happening.

This is just a suggestion that may fit the symptoms. It sounds like you are not getting fuel at times which could mean that your fuel pump is supplying fuel, but your in line fuel filter is getting clogged and not letting fuel pass to the injectors. The fuel that has mandated alcohol in it is highly hydroscopic and picks up a lot of water that ends up in your tank and mixes with the rust that it causes on the steel tank. That gunk is sucked up by the pump and under pressure blocks your fuel filter after a while, and is so impacted that it cuts off the fuel flow stalling the engine. If you let it sit for a while, then the impacted debris settles down in the bottom half of the filter allowing the fuel to flow, but under pressure it builds up at the exit port again. It could be as simple as changing the fuel filter.