What steps are used to measure rail or fuel pressure?

• A. Connect a fuel pressure gauge to a service port on the rail, engine off, then compare to spec.
• B. Connect a fuel pressure gauge to a service port on the rail, key on or start the engine as specified, compare to spec, and observe for pressure drop or fluctuation.
• C. Remove the rail and measure with a voltmeter.
• D. Use a thermometer to measure rail temperature and estimate pressure.

Answer: (B)