High Fuel Pressure

Hi:

When you say it slowly drops, how long do you mean? If it is within a few seconds, that's an issue.

As far as possible causes, you could have a fuel injector leaking, or a fuel leak in the fuel line, and the fuel pump has a one-way valve that can allow fuel to feedback to the tank.

Let me know as much as you can. For example, does it run? If it does, do you see any dark gray or black smoke from the exhaust? If the check engine light is staying on while the engine runs, have you scanned for diagnostic trouble codes?

Also, fuel pressure should be between 41 and 47 with the key on and the engine off. It almost sounds like something is plugged after the fuel pressure regulator. See pic below. After the fuel reaches the fuel rail, unused fuel is returned to the fuel tank by a separate pipe. The return is attached to the fuel pressure regulator. That is where I am suspecting a possible issue. Something is blocking the return.

Let me know.

Joe

See pic below