Fuel pumps on Toyota are all go or all no, no inbetween. Sounds like you are having a problem with the fuel rail bleeding off pressure. Since it does start and run fine after initial startup I would start looking for areas where air can enter the system and allow the fuel to bleed off. Most likely culprits being the pulsation dampner and pressure regulator. Either can be worn out and would allow air to slowly seep in. Also if any fuel system work was done just prior to the problem beginning, the threads may not have had any sealer applied to them...again creating a slow air leak. Interesting too because air will get in, but even under pressure, fuel wont spray out.

~Darin <img src="/forums/images/graemlins/baby.gif" alt="" />