Mariner Mercury 105/140 JET, Service Manual

Page: 304 / 797

90-824052R3 JUNE 2002 FUEL SYSTEMS - 3D-31
Pressure Regulator Test
Purpose: This test will determine if a weak, plugged
or open pressure regulator is causing
inadequate fuel pressure in the system.
1. Connect pressure gauge to EFI test port.
55180
a
a - Test Port
2. Turn ignition key switch to “ON” position and
check fuel pressure reading on gauge. If
pressure reading is below 34 psi (234 kPa) go to
step 3 following.
OFF
ON
START
3. Remove fuel pressure regulator, but do not
disconnect any hoses from regulator.
4. Put discharge end of regulator in clean container.
5. Turn ignition key switch to “ON” position.
OFF
ON
START
6. Check for fuel flow out of regulator.
Results: If steady stream of fuel exits regulator into
container and pressure is below 34 psi (234
kPa), replace pressure regulator.
If low or no fuel exits regulator into container and
pressure is below 34 psi (234 kPa), perform voltage
checks on electric fuel pump, following.
If low or no fuel flow exits regulator into container and
pressure is above 36 psi (248 kPa), replace
regulator.