Fuel Pump Capacity Test
- Remove cap from the pressure test port in fuel rail. See Figure . Connect a 0-60 psi (0-4.22 kg/cm2 ) fuel pressure gauge to pressure fitting on fuel rail. Start and run engine at idle. Note fuel pressure.
- Pressure should be roughly 31 psi (2.18 kg/cm2 ) with vacuum hose connected to fuel pressure regulator and 39 psi (2.74 kg/cm2 ) with vacuum hose disconnected. If fuel pressure is incorrect, check fuel supply and return lines/hoses for kinks or restrictions.
- Check fuel pump flow rate (capacity). A good fuel pump will deliver at least 2.11 pints (1 liter) of fuel per minute with the hose section of fuel return line pinched off. If fuel pump capacity is incorrect, inspect fuel supply system for a plugged filter or plugged fuel pump inlet filter.