Electronic Fuel Injection (Efl) System; Introduction; Using The Test Procedures; Efi System Tests - Mercury 150 EFI Service Manual

FUEL INJECTION

Electronic Fuel Injection (EFl) System

Introduction

The troubleshooting information provided here consists of preliminary checks (checks to
be followed before proceeding with EFI tests), diagrams (fuel flow and electrical wiring),
component description (from diagrams), flow charts (low pressure fuel delivery, high pres-
sure fuel delivery, fuel delivery vs. electrical delivery), problem diagnosis, and a series of
test and check procedures that will help isolate problems associated with the fuel injection
system. Each test/check (listed) can be completed without major fuel system disassembly.

Using the Test Procedures

Read the entire test before beginning to perform outlined procedures. Study the RESULTS
material prior to testing. This will help in determining that each test is providing desired
results.

EFI System Tests

EFI Electrical System and ECM Check
Fuel Gauge Connection/Pressure Test
Vapor Separator Fuel Delivery Test
Vapor Separator Float Test
Water Separating Filter Flow Test
Pulse Fuel Pump Delivery Test
Final Filter Check
Fuel Pressure Regulator Test
Electric Fuel Pump Test
Injector Electrical Test
Injector Fuel Delivery Test
Injector Operating Test
Induction Manifold Leak Check
Sensor Tests

Safety Precautions

Always use approved safety glasses or goggles when working on pressurized fuel
systems.
Motor fuels are extremely flammable. Do not show open sparks or flames when
working near fuel systems.
To avoid potential fire hazards, use extreme caution when connecting and discon-
necting fuel line connections and test adaptors. Do not allow fuel to spill on hot
engine parts or on live electrical connections.
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CAUTION
DANGER
WARNING
90-883728 JULY 2001