Crank but no Start. ( 2000 F150 4.6L )

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2000 Ford F150 XL 4.6 Trittan V8 137,000 miles Only way the truck starts, when the ignition is turned to the on position for a minimum of 30 sec. After this is done complete the starting cycle, the truck will start with no issues. If you attempt to start it without waiting a minimum 30 seconds, it just cranks but won't start. I have replace the following parts , PVC valve, fuel pump , fuel filter, TP sensor, crank position sensor, cam position sensor, fuel pressure regulator. I Ohm'd out the fuel injectors they checked out good. The only noticeable sign is low fuel pressure. It's steady at 27psi. should be between 35 - 45 psi. Fuel pressure does holds for more then five min. A white mist smoke, along with a lot condensation coming out tail pipe. When the truck is running is runs perfect. There's two OBD codes P0151 , P0161 , Someone Please help.

How long has your 2000 Ford F-150 had this problem?

Three months