why my 3000gt 1993 vr 4 sparks plug wires sparks but the other two will sparks later after a few minutes . What could be wrong with it?

yes well this is a typical problem...your ignition is having trouble finding GROUND because the ground is buggered up with corrosion...from repeated starts of your 300 or more Amps requirement of the startermotor...again and again...until a layer of "semiconductor" corrosion will grow...not only does this not allow full steady voltage through at the smaller requirements such as ignition, Control, and fuel systems...so what we must do is undo the end of the Black battery cable (not the clamp end, the other end) what connects to the fender/chassis/ground and undo that bolt...break out the coarse wirebrush and brush the lug and territory where that lug bolts to~ this will assure a needed Ground circuit....which 'till now has to "bake unto itself" with potential energy...need ground....lots of it and SOLID connection....are we on the same page here?~

...also a five year old battery will issue diminished performance...don't risk a disappointment of bein' stranded...get a NEW battery...okay?~

Are the two that are not sparking on the same coil? If so one bad plug or plug wire will not allow either to fire. Also could be bad coil or computer. But I would check the plugs and wires first. One way to test is get two spare plugs and wires and attach they to that coil and lay them on the metal of the valve cover. Start car and watch for them to fire. You should have a sparking light show if coil and computer is good. If that's what you see and when you plug the old ones back up and get no fire again replace the plugs and wires. Remember to use platinum tip plugs only.