The fuel rail is SUPPOSED to retain pressure. If it bleeds off too quickly you'll have issues with warm starts: low pressure and possibly fuel vapor locking up the rail. Culprits: FPR and FPD.
If you have a 7M-GE the FC switch inside the AFM may be failing as well. If this is the case the fuel pump may lose power when the throttle plate is close to closed and not completely closed.
Protip: The FC circuit on the 7M can be wired to a momentary switch *TEMPORARILY* as a fuel primer switch. Just put the key to the ON position and press the button for a count of 5 or so to bring the system's pressure up.
@rr0621: Have you checked for diagnostic codes? Cleaned the ISCV? Is the TPS working and properly calibrated? If you don't know how to check these please try searching the forum for these specific items I think they're more likely to be the source of your problem.
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