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Per the Mercruiser No. 17 GM 5.0L/5.7L V8 Marine Engines—Throttle Body Injection Fuel System Diagnosis: "Ignition ON, pump pressure should be 28-32 PSI (234-207 kPa). This pressure is controlled by spring pressure within the regulator assembly." I bought the TBI pressure kit and did the test myself. It is spot on spec.