I have been having problems starting my car after its hot and sits for 20 Min's approx, I have to press the gas peddle to get it to start and turn it over lots

what i have done so far is:
  1. changed fuel filter
  2. checked spark while the symptom is happening and with spark plug wire tester and it showed spark
  3. cleaned throttle body tore it apart
  4. cleaned MAF sensor it reads (g/s) 4.92 on obd2 (not sure if that is goo still learning about this)
  5. checked codes with obd2 scanner
  6. codes showed up as
  7. p0455 - p0128 i have a ect just have to change it my reading is 89 de C
  8. changed antifreeze (to prep for winter)


What I get when I hook up my fuel pressure gauge and the car is running is 57-58 psi but when I turn my key off it drops to 0 right away is this normal?

When I turn on the key without starting the car I can hear the pump priming but the gauge reads 0 psi till I turn it over quite a bit then the pressure climbs up to 57 psi and starts right away (again is this normal or is it not priming right? )