The Z22SE has an electric pump but it's not a high pressure one, but the Z22YH which has direct injection does have a high pressure pump which have caused issues.
The fuel pump is located immersed in the petrol tank along with a fuel filter located under the car just in front of the rear LHS wheel.
There is a fuel pressure regulator located on the RHS end of the fuel rail which keeps pressure constant @ 3.0-3.5 bar.
To test for fuel pressure at the fuel rail, remove the engine cover, then locate the valve assembly which can be found on the top of the rail (it looks similar to a tyre valve). Unscrew the cap from the valve and hold a cloth over the valve, then depressurise the system by pressing the centre of the valve with a suitable screwdriver. Be aware that fuel will squirt at reasonable pressure and may spray over the engine bay.
Can you give more details of the issues you are experiencing?