Injector Load Test; Fuel Rail Assembly Leakage Test - Mercury 150 EFI Service Manual

FUEL INJECTION

Injector Load Test

An injector load test can be performed using the Digital Diagnostic Terminal (DDT). An au-
dible click will be heard each time an injector is activated. This test will verify that each in-
jector is operating mechanically, not that each injector is allowing the proper amount of fuel
to enter each cylinder. Refer to DDT Reference Manual 90-881204–1 for test procedures.

Fuel Rail Assembly Leakage Test

Purpose: This test will determine if the supply tube or injector o-rings are leaking or if an injector is stuck open.
1. Remove 4 screws securing throttle plate assembly to air plenum and remove assem-
bly.
a -
2. Put ignition key switch in "ON" position. Electric fuel pump should run for approximately
2 seconds.
3. While pump is running, observe fuel rail.
Results: If leakage is observed, refer to Fuel Rail Removal. Replace o-rings and/or injectors as required.
Page 3B-30
a
Screws
OFF
b
a
b -
ON
START
58898
Throttle Plate Assembly
90-883728 JULY 2001