1999 Mercruiser HI-Performance GM 377 EFI Engine Service Manual
- Home
- Stern drives
- Mercury
- 1999 Mercruiser HI Performance GM 377 EFI Engine Service Manual
Original Service Manual Number 7
MERCRUISER HI-PERFORMANCE GM 377 EFI ENGINE 377 CID (6.2L)
Publication Number: 90-840500
This is high quality service manual with high quality diagrams.
Manual is fully searchable and deeply indexed for easy access to information.
To find information in PDF file please use "Ctrl+F" or "Command+F" for Mac and enter keywords you need to find in a manual.
File will be available for download in minutes!
"1999 Mercruiser HI-Performance GM 377 EFI Engine Service Manual" manual can be saved to any computer hard drive, flash storage, burned to a CD or DVD ROM or any other digital media.This Manual PDF file is:
- + Printable: Yes
- + Viewable on: MS Windows, Mac, Android, iOS, Linux
- + Requires: Adobe Acrobat/Preview
Once manual is downloaded any number of pages could be printed or it could be printed in whole.
Manual could be opened in Adobe Acrobat on any mobile device (like iPad, iPhone or Android device etc.) any computer capable of viewing a PDF files including IBM compatible computers running Windows, Linux (or any other flavor of UNIX). Apple Computers have native support for PDF files.
Write a Review
Full list of manual chapters:
MERCRUISER HI- PERFORMANCE GM 377 EFI ENGINE
Notice
Notice to Users of This Manual
Cleanliness and Care of Product
Service Manual Outline
Table of Contents
Section 1a General Information
Section 1b Maintenance
Section 1c Troubleshooting
Section 2a MCM 377 BRAVO
Section 3a CID/6.2L Engine
Section 4a Starting System
Section 4b Ignition System
Section 4c Charging System
Section 4d Instrumentation
Section 4e Wiring Diagrams
Section 5a Fuel Injection System Operation
Section 5b Fuel Injection Delivery System
Section 5c Fuel Injection System Assembly
Section 5d Fuel Injection System Troubleshooting
Section 5e Diagnostics
Section 6a Cooling System
Section 7a, 7b, and 7c Exhaust System
IMPORTANT INFORMATION
Table of Contents
Introduction
How to Use This Manual
Page Numbering
How to Read a Parts Manual
Power Steering Pump Assembly
Directional References
Engine Rotation
Engine Serial Number Locations
Propeller Information
Water Testing New Engines
Boat and Engine Performance
Boat Bottom
Marine Fouling
Weight Distribution
Water in Boat
Elevation and Climate
IMPORTANT INFORMATION
Table of Contents
Tools
Lubricants / Sealants / Adhesives
Fluid Capacities
Engine
Sterndrive
Power Steering Fluid
Maintenance Schedules
Maintenance Intervals
Maintenance Charts
Engine and Tune-Up Specifications
Break-In Period
After Break-In Period
End of First Season Checkup
Specifications
Fuel Recommendations
Test For Alcohol Content In Gasoline
Crankcase Oil
Overfilled Crankcase Oil
Checking Engine Oil Level / Filling
Changing Oil and Filter
Changing Water Separating Fuel Filter
Power Steering System
Checking Fluid Level
Engine Cold
Filling and Bleeding
Flushing Cooling System
Lubrication
Throttle Cable
Shift Cable
Engine Coupler/U-Joint Shaft Splines
Cleaning Flame Arrestor
Serpentine Drive Belt
Replacing and/or Adjusting Tension
Inspection
Ignition Timing
IMPORTANT INFORMATION
Table of Contents
Used Spark Plug Analysis
Normal Condition
Chipped Insulator
Wet Fouling (Oil Deposits)
Cold Fouling
Overheating
High Speed Glazing
Scavenger Deposits
Pre-Ignition Damage
Reversed Coil Polarity
Splashed Deposits
Mechanical Damage
Poor Boat Performance And/Or Poor Maneuverability
Improper Full Throttle Engine RPM
RPM Too High
RPM Too Low
Basic Checks
Fuel System Rich
Fuel System Lean
Miscellaneous
Engine Will Not Crank Over
Charging System Inoperative
Noisy Alternator
Instrumentation Malfunction
Radio Noise
Poor Fuel Economy
Engine Runs Poorly at Idle
Engine Runs Poorly At High RPM
Engine Acceleration Is Poor
Troubleshooting with Vacuum Gauge
Engine Noise
Important Information
Valve Cover Area
Cylinder Area
Camshaft Area
Crankshaft Area
Miscellaneous
Oil Pressure
Low Oil Pressure
High Oil Pressure
Excessive Oil Consumption
Water In Engine
Important Information
Water on Top of Pistons
Water in Crankcase Oil
Engine Overheats (Mechanical)
Engine Overheats (Cooling System)
Insufficient Water Flow from Belt Driven Seawater Pickup Pump
Power Steering
Poor, Erratic, or No Assist
Noisy Pump
Fluid Leaks
Troubleshooting Silent Choice Exhaust Silencer System
Compressor Will Not Run - Testing Mode Switch
Compressor Will Not Run - Testing Air Pump
Air pump Runs - System Inoperative
THIS PAGE IS INTENTIONALLY BLANK
REMOVAL AND INSTALLATION
Table of Contents
Torque Specifications
Tools
Lubricants / Sealants / Adhesives
Preparation
Removal
Installation
Alignment
ENGINE
Table of Contents
Tightening Torques and Lubes
Lubricants / Sealants / Adhesives
Tools
Special Tools
Specifications
General Specifications
Engine Specifications
General Information
Repair Procedures
Engine Identification
Engine Rotation
Description
Crankshaft
Piston and Connecting Rods
Camshaft and Drive
Cylinder Head
Valve Train
Intake Manifold
Lubrication System
Bearing Failures
Piston Failures
Pre-Ignition
Detonation
Engine Mounts
Rocker Arm Cover
Removal
Installation
Intake Manifold
Removal
Cleaning and Inspection
Installation
Rocker Arm / Push Rod
Removal
Cleaning and Inspection
Installation
Valve Adjustment
Hydraulic Valve Lifters
Locating Noisy Lifters
Removal
Cleaning and Inspection
Installation
Valve Stem Oil Seal / Valve Spring
Removal - Head Installed
Valve Assembly (Exploded View)
Installation - Head Installed
Cylinder Head
Removal
Cleaning and Inspection
Installation
Cylinder Head and Valve Conditioning
Disassembly
Cleaning and Inspection
Valve Springs - Checking Tension
Rocker Arm Stud Replacement
Valve Seat Repair
Valve Grinding
Reassembly
Crankcase Oil Dipstick Specifications
Oil Pan
Removal
Cleaning and Inspection
Installation
Oil Pump
Exploded View
Removal
Disassembly
Cleaning and Inspection
Reassembly
Installation
Torsional Damper
Removal
Installation
Crankcase Front Cover and Oil Seal
Removal
Installation
Flywheel
Removal
Cleaning and Inspection
Installation
Rear Main Oil Seal
Removal
Cleaning and Inspection
Installation
Rear Main Oil Seal Retainer
Removal
Cleaning and Inspection
Installation
Main Bearings
Inspection
Checking Clearances
Replacement
Connecting Rod Bearings
Inspection and Replacement
Connecting Rod / Piston Assembly
Removal
Disassembly
Cleaning and Inspection
Reassembly
Installation
Crankshaft
Removal
Cleaning and Inspection
Installation
Timing Chain and Sprockets
Removal
Cleaning and Inspection
Crankshaft Sprocket
Removal
Installation
Checking Timing Chain Deflection
Camshaft
Measuring Lobe Lift
Removal
Inspection
Installation
Camshaft Bearings
Removal
Cleaning and Inspection
Installation
Cylinder Block
Cleaning and Inspection
Oil Filter By-Pass Valve and Adaptor Assembly
Removal
Cleaning and Inspection
Installation
ELECTRICAL SYSTEMS
Table of Contents
Identification
Delco PG260F1 Permanent Magnet Gear Reduction Starter
Replacement Parts Warning
General Precautions
Typical Starting System Components
Positive Current Flow
Battery
Battery Cable Recommendations
Maintenance
Testing
Storage
Charging Guide
How Temperature Affects Battery Power
Standard Starter Slave Solenoid
Identification
Testing / Replacement
Testing
Starter Motor Voltage
Voltage Drop In Starting System
Delco PG260F1 Starter
Specifications
Starter Specifications
Torque Specifications
Lubricants / Sealants / Adhesives
Description
Exploded View - PG260F1 Starter
Motor
Removal
Disassembly
Cleaning and Inspection
Reassembly
Checking Pinion Clearance
Installation
ELECTRICAL SYSTEMS
Table of Contents
Ignition Control System Components
Replacement Parts Warning
General Precautions
EFI System Maintenance Precautions
Torque Specifications
Tools
Lubricants / Sealants / Adhesives
Ignition System Specifications
Distributor
Coil
Spark Plugs
Firing Order
Timing
Spark Plugs
Removal
Inspection
Replacing
Spark Plug Wires
Inspection
Replacing
GM EST Distributor
Removal
Disassembly
Cleaning and Inspection
Testing Pickup Coil
Reassembly
Installation
ELECTRICAL SYSTEM
Table of Contents
General Precautions
Electrical System Precautions
Replacement Parts Warning
Multiple Engine Battery Precautions
Recommendations
Identification
Mando 65 Amp Alternator
Specifications
Tools
Lubricants / Sealants / Adhesives
Exploded View
Torque Specifications
Description
Alternator Repair
Removal
Testing
Charging System
Charging System Resistance
Circuitry
Disassembly
Cleaning and Inspection
Reassembly
Pulley Installation
Installation
Battery Isolator Diagram
ELECTRICAL SYSTEM
Table of Contents
Tools
Lubricants / Sealants / Adhesives
Identification
Description
Lighting Options
Gauges
Circuits
Oil, Fuel and Temperature
Battery Gauge
Cruiselog Meter
Vacuum Gauge
Speedometer
Tachometer
Gauge Replacement
Senders
Oil Pressure
Engine Coolant Temperature Sender (ECT)
Switches
Ignition Key Switch
Lanyard Stop Switches
Start/Stop Switch
Audio Warning System
Buzzer
Oil Pressure Switch
Sterndrive Gear Lube Monitor Switch
ELECTRICAL SYSTEMS
Table of Contents
Starting and Charging Harness
EFI and Ignition System
Starting and Charging System
FUEL SYSTEMS
Table of Contents
Special Tools
Service Precautions
General Information
Electrostatic Discharge Damage
Diagnostic Information
Wiring Harness Service
Wiring Connector Service
Abbreviations
ECM Self-Diagnostics
Diagnostic Code Tool With Malfunction Indicator Lamp
Intermittent Malfunction Indicator Lamp
Reading Codes
Scan Tools
EFI Diagnostic Circuit Check
Scan Tool Use With Intermittents
Non-Scan Diagnosis of Driveability Concerns (With No Codes Set)
Electronic Control Module (ECM) and Sensors
General Description
Computers and Voltage Signals
Analog Signals
Digital Signals
Engine Control Module (ECM)
Speed Density System
ECM Input and Sensor Descriptions
Spark Management
High Energy Ignition with Ignition Control (IC)
Modes Of Operation
Base Ignition Timing
Results of Incorrect Operation
Fuel Metering System
General Description
Cool Fuel Systems
Modes of Operation
FUEL SYSTEM
Table of Contents
Specification
Torque Specifications
Tools
Lubricants / Sealants / Adhesives
Replacement Parts Warning
Precautions
Fuel Supply Connections
Fuel Delivery System
Recommendations
Cool Fuel System Exploded View
Fuel System Flow Diagram
Water Separating Fuel Filter
Water Separating Fuel Filter Replacement
Cool Fuel System Repair
Removal
Disassembly
Reassembly
Installation
Vacuum And Vent Hose Routing
FUEL SYSTEM
Table of Contents
Service Precautions
Torque Specifications
Exploded Views
Plenum, Throttle Body And Flame Arrestor
Intake Manifold And Fuel Rails
Fuel Pressure Relief Procedure
Throttle Body Components
Flame Arrestor
Throttle Body
Plenum
Fuel Rails
Fuel Injectors
Manifold Absolute Sensor (MAP)
Throttle Position Sensor (TP)
Idle Air Control Valve (IAC)
Knock Sensor
Fuel Pump Relay
System Relay
Engine Control Module (ECM)
Engine Coolant Temperature Sensor (ECT)
FUEL SYSTEMS
Table of Contents
Scan Tool Normal Specifications ( Idle / Warm Engine / Closed Throttle / Neutral)
Important Preliminary Checks
Before Starting
Visual / Physical Check
Intermittents
Hard Start Symptom
Surges and/or Chuggles Symptom
Lack of Power, Sluggish or Spongy Symptom
Detonation / Spark Knock Symptom
Hesitation, Sag, Stumble Symptom
Cuts Out, Misses Symptom
Rough, Unstable, or Incorrect Idle, Stalling Symptom
Poor Fuel Economy Symptom
Dieseling, Run-On Symptom
Backfire Symptom
FUEL SYSTEMS
Table of Contents
Special Tools
Diagnostic Circuit Check
Scan Tool Normal Specifications (Idle/Warm Engine/Closed Throttle/Neutral)
Diagnostic Trouble Codes
ECM Connector and EFI Symptoms Charts
J-1 Circuits
J-2 Circuits
Wiring System Diagrams
Wiring System Diagram With GM EST Distributor
Injector Balance Test
Test Procedure
Test Example
General Diagnostic Tests
On-Board Diagnostic (OBD) System Check
Chart A-1 (1 of 2): No Malfunction Indicator Light (MIL) or No Data Link Connector ( DLC) Data
Chart A-1 (2 of 2): No Malfunction Indicator Light (MIL) or No Data Link Connector ( DLC) Data
Chart A-2 (1 of 2): MIL ON Steady - Will Not Flash DTC 12
Chart A-2 (2 of 2): MIL ON Steady - Will Not Flash DTC 12
Chart A-3 (1 of 2): Engine Cranks But Will Not Run
Chart A-3 (2 of 2): Engine Cranks But Will Not Run
Chart A-4 (1 of 2): Fuel System Diagnosis
Chart A-4 (2 of 2): Fuel System Diagnosis
Chart A-5 (1 of 2): Fuel System Electrical Test
Chart A-5 (2 of 2): Fuel System Electrical Test
Chart A-6 (1 of 2): EFI System/Ignition Relay Check
Chart A-6 (2 of 2): EFI System/Ignition Relay Check
Chart A-7 (1 of 5): Ignition System Check
Chart A-7 (2 of 5): Ignition System Check
Chart A-7 (3 of 5): Ignition System Check
Chart A-7 (4 of 5): Ignition System Check
Chart A-7 (5 of 5): Ignition System Check
Chart A-8 (1 of 2): Idle Air Control (IAC) Functional Test
Chart A-8 (2 of 2): Idle Air Control (IAC) Functional Test
Discrete Input Circuit Check - Non-Scan Only (1 of 5)
Discrete Input Circuit Check(2 of 5)
Discrete Input Circuit Check (3 of 5)
Discrete Input Circuit Check (4 of 5)
Discrete Input Circuit Check (5 of 5)
Clearing Trouble Codes
Clearing Codes Using CodeMate Tester
Clearing Codes Using Scan Tool
Diagnostic Testing
Code 14 (1 of 3): Engine Coolant Temperature (ECT) Sensor Circuit (Low Temperature Indicated)
Code 14 (2 of 3): Engine Coolant Temperature (ECT) Sensor Circuit
Code 14 (3 of 3): Engine Coolant Temperature (ECT) Sensor Circuit
Code 15 (1 of 2): Engine Coolant Temperature (ECT) Sensor Circuit (High Temperature Indicated)
Code 15 (2 of 2): Engine Coolant Temperature (ECT) Sensor Circuit
Code 21 (1 of 3): Throttle Position (TP) Sensor Circuit (Signal Voltage High)
Code 21 (2 of 3): Throttle Position (TP) Sensor Circuit
Code 21 (3 of 3): Throttle Position (TP) Sensor Circuit
Code 22 (1 of 3): Throttle Position (TP) Sensor Circuit (Signal Voltage Low)
Code 22 (2 of 3): Throttle Position (TP) Sensor Circuit
Code 22 (3 of 3): Throttle Position (TP) Sensor Circuit
Code 33 (1 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Signal Voltage High)
Code 33 (2 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit
Code 33 (3 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit
Code 34 (1 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit (Signal Voltage Low)
Code 34 (2 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit
Code 34 (3 of 3): Manifold Absolute Pressure (MAP) Sensor Circuit
Code 41 (1 of 2): Ignition Control (IC) Circuit (Open IC Circuit)
Code 41 (2 of 2): Ignition Control (IC) Circuit
Code 42 (1 of 3): Ignition Control (IC) Circuit (Grounded IC Circuit Open or Grounded Bypass)
Code 42 (2 of 2): Ignition Control (IC) Circuit
Code 51 (1 of 1): Calibration Memory Failure
COOLING SYSTEM
Table of Contents
Torque Specifications
Tools
Special Tools
Lubricants / Sealants / Adhesives
Specifications
Cooling System Capacity
Thermostat
Seawater Inlet Recommendations
Transom Mounted or Thru-Hull Seawater Pickups and Hose
Seacock (Seawater Inlet Valve)
Sea Strainer
Seawater Pickups
Thru-Hull Mounted
Transom Mounted
Quicksilver Sea Strainer
Removal
Cleaning and Inspection
Installation
Seawater Pickup Pump
Output Test
Disassembly
Reassembly
Seawater Pump Bearing Housing
Disassembly
Cleaning and Inspection
Reassembly
Water Circulating Pump
Removal
Cleaning and Inspection
Installation
Drive Belt Tension Adjustment
Flushing Seawater Cooling System
Thermostat
Removal
Testing
Installation
Water Flow Diagram
EXHAUST SYSTEM
Table of Contents
Exhaust System Requirements
Exhaust Elbow Risers
Thru-Transom Exhaust
Exhaust Hose Connection
Exhaust Tube Requirements
EXHAUST SYSTEM
Table of Contents
Torque Specifications
Lubricants / Sealants / Adhesives
Disassembly
Cleaning and Inspection
Installation
EXHAUST SYSTEM
Table of Contents
Torque Specifications
Lubricants / Sealants / Adhesives
Bullhorn Exhaust
Component Replacement
Shutter Replacement
Thru-Transom Exhaust
Shutter Replacement
Component Replacement
Below Swim Platform Exhaust Pipe
Silent Choice Exhaust System
Exhaust Tube Installation
Air Tube Routing
Maintenance
Exhaust Muffler Kit
Cleaning and Inspection
Installation
Maintenance
POWER STEERING SYSTEM
Table of Contents
Torque Specifications
Tools
Special Tools
Lubricants / Sealants / Adhesives
Precautions
Serpentine Belt Routing
Serpentine Belt Adjustment
Removal
Installation
Power Steering Pump and Components (Exploded View)
Power Steering Pump
Pump Pulley Replacement
Pump Assembly
Removal
Installation
Hydraulic Hoses and Fluid Cooler
High Pressure Hose (Pump-to-Control Valve)
Low Pressure Hose (Cooler-to-Pump)
Low Pressure Hose (Control Valve-to-Cooler)
