My T100 has also had some problems starting during the past 6-7 months. When it is warm out and the truck has sat for a few hours in the afternoon sun it takes a lot longer while cranking to start.

I had two ideas about what is causing this. One, the fuel pump is not strong enough to build the pressure required for starting (something that happens to some toyotas per my instructor). Two, the fuel pressure regulator is faulty. My understanding of the pressure regulator is that it bleeds off pressure when the pressure is too high. I did not think that it maintained a minimum pressure.