Mariner Mercury 105/140 JET, Service Manual

Page: 315 / 797

3D-42 - FUEL SYSTEMS 90-824052R3 JUNE 2002
Condition Possible Source Action
Engine Surges Between 4000
And 5000 RPM – Intermittant Switch Box Failure.
– Final Filter Clogging.
– T.P.S. – Improper Adjustment.
– Detonation Control (Model 200
Only).
– Injector Connector Problem.
– Vapor Separator Flooding Over.
– Injector Filter Clogged.
Refer to Section 2A Electrical and
Ignition for tests.
Perform Final Filter Check (page
3D-29).
Refer to Section 2A Electrical and
Ignition for T.P.S. adjustment.
Perform Detonation Test (page
3D-38).
Perform Injector Fuel Delivery
Test (page 3D-34).
Check for fuel coming out of vapor
separator vent hose.
Refer to Injector Fuel Delivery
Test (page 3D-34).
Engine Idles Ok But Stumbles At
Off Idle Speeds – Improper EFI Setup.
– Failed Switch Box.
– Failed Or Disconnected EFI
Sensors.
– Fuel Delivery Problem.
– Manifold Fuel Leak.
– R.F.I.* Problem.
– Stator (High Speed Winding).
– Induction Manifold Air Leak.
Refer to Section 2A Electrical and
Ignition for proper EFI set up pro-
cedures.
Refer to Section 2A Electrical and
Ignition Tests.
Perform EFI sensor tests (pages
3D-35 thru 3D-40).
Follow Low/High Pressure Fuel
Route Flow Charts and Fuel Rail
Electrical/Fuel Determination Flow
Chart (pages 3D-23 thru 3D-25).
Perform Induction Manifold Leak
Check (page 3D-36).
Install BUZ8H Spark Plugs.
Refer to Section 2A Electrical and
Ignition for tests.
Check manifold cover gasket,
manifold to reed block housing
gasket and reed block housing to
crankcase gasket.
Engine Idles Rough (May Lean
Sneeze) – Acceleration Ok; Full
Throttle Ok – Improper EFI Setup.
– MAP Sensor Failure.
Refer to Section 2A Electrical and
Ignition for proper EFI set up pro-
cedures.
Refer to Electronic Fuel Injection
Tester Manual 91-11001A2.