Also if the pressure is below the normal is that due to the bad fuel pump.

 

41-47psi at idle with the vacuum hose to the regulator removed. A clogged fuel filter could cause lower pressure.

 

The fuel pressure should be around 41-47psi when engine is not running with the key in the on position, and the pressure should drop 3-10psi when the engine is running.

Low fuel pressure could be due to the fuel pump, clogged fuel filter, or clogged injector.