Mariner Mercury 105/140 JET, Service Manual

Page: 234 / 797

90-824052R3 JUNE 2002 FUEL SYSTEMS - 3C-27
Pressure Regulator Test
Purpose: This test will determine if a weak, plugged
or open pressure regulator is causing
inadequate fuel pressure in the system.
NOTE: Induction manifold cover shown removed for
illustrative purposes only.
Procedure: STEP 1: Connect pressure gauge to
EFI test port.
51796
STEP 2: Turn ignition key switch to “ON” position
and check fuel pressure reading on
gauge. If pressure reading is below 36 psi
(248 kPa) go to step 3 following.
OFF
ON
START
STEP 3: Remove fuel pressure regulator, but do
not disconnect any hoses from regulator.
STEP 4: Put discharge end of regulator in clean
container.
STEP 5: Turn ignition key switch to “ON” position.
OFF
ON
START
STEP 6: Check for fuel flow out of regulator.
Results: If steady stream of fuel exits regulator
into container and pressure is below 36 psi
(248 kPa) replace pressure regulator.
If low or no fuel exits regulator into container and
pressure is below 36 psi (248 kPa) perform electric
fuel pump “pressure” test.
If low or no fuel flow exits regulator into container and
pressure is above 39 psi (269 kPa) replace regulator.