Mariner Mercury 105/140 JET, Service Manual

Page: 227 / 797

•
Perform low pressure checks (3C-19) before
performing checks on high pressure route.
•
Install fuel pressure gauge (P/N 91-16850A2)
on to manifold pressure port.
•
Place ignition switch in “OFF” position 30 sec-
onds before testing.
•
Place ignition switch in “ON” position and note
pressure within 30 seconds (36 to 39 psi; 248 to
269 kPa).
No or low fuel pressure Pump does not run Fuel pressure above 39 psi (269 kPa)
Perform Final Filter Check
(page 3C-26). Clogged or faulty fuel pressure
regulator remove and replace. Perform Electric Fuel Pump “Pro-
cedure B” Test (page 3C-28).
Final filter OK. Final filter clogged.
Perform Fuel Pressure Regula-
tor Test (page 3C-27). Clean or replace final filter.
Steady stream of fuel (pressure
still below 36 psi). Low or no fuel flow.
Replace fuel regulator.
Perform Electric Fuel Pump Test
(page 3C-28).
Voltage from ECM driver circuit
OK. Low or inconsistent voltage from
ECM driver circuit.
Replace fuel pump. Replace ECM.
Results Results
Results
Results
Results
Results
3C-20 - FUEL SYSTEMS 90-824052R3 JUNE 2002
EFI Fuel Management (High
Pressure Fuel Route)