ravemind

I have a 94 extended cab 4x4 22re. It starts fine when I first start it, but after I drive it 5-10 miles and turn it off sometimes it will not start it drags like the battery is dead. after it sets for about 30 minutes or so it will start just fine. I have replaced battery, battery cables, starter, fuel filter, spark plugs, and changed the oil. it has not helped at all. Nobody seem to know whats causing the problem. Any help would be greatly appreciated. Cold Start valve?
Thanks