© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Publisher The Goodheart-Willcox Co., Inc. Tinley Park, Illinois by Russell Krick

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Diesel injection maintenance  Diesel injection diagnosis  Diesel injection service

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Refer to manufacturer’s service manual for periodic maintenance  Change fuel filters periodically  Some filters may be drained to bleed off water

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Inlet Connection Screen Check if problems point to injection system

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Locating Fuel Leakage Pressure is high enough to make spray puncture your skin!

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Visual Inspection Check hoses, lines, filters, and linkages

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Cleanliness  Use clean, lint-free shop rags  Use compressed air to blow dirt from fittings before disassembly  Always cap a fitting that is disconnected

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Check for:  abnormal exhaust smoke  excessive knock  engine miss  “no start” condition  lack of power  poor fuel economy

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Abnormal Exhaust Smoke A small amount during start-up, cold operation, or acceleration is normal

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Black Smoke  Rich air-fuel mixture allows carbon (ash) to blow out of the exhaust system  Causes:  injection pump  timing  air cleaner  injectors  fuel  engine condition

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only White Smoke  Occurs during cold starts  Condensed fuel particles  Causes:  glow plugs  low compression  thermostat stuck open  bad injector spray pattern  late injection timing  injection pump

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Blue Smoke  Oil consumption  Causes:  worn piston rings  scored cylinder walls  leaking valve stem seals

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Smoke Meter Testing device that measures amount of smoke in diesel exhaust

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Smoke Meter  Measures amount of light that can shine through an exhaust sample  If the exhaust smoke blocks too much light, it fails to meet specifications

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Excessive Knock  All diesels produce a knocking sound  Fuel ignites spontaneously and burns rapidly  Ignition lag is the time span between injection and ignition  If lag is too long, too much fuel will ignite at once

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Causes of Excessive Knock  Low operating temperature  Early injection timing  Low compression  Fuel contamination  Oil consumption

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Engine Miss  One or more cylinders not firing  Causes:  faulty injectors  clogged fuel filters  incorrect injection timing  low compression  leaks  faulty injection pump

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only No Start  Causes:  inoperative glow plugs  restricted air or fuel flow  bad fuel shutoff solenoid  contaminated fuel  faulty injection pump

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Lack of Power  Causes:  throttle cable adjustment  governor setting  fuel filters  air filter  compression

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Poor Fuel Economy  Causes:  fuel leak  clogged air filter  incorrect injection timing  leaking injectors

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Scanning Diesel Problems  Connect a scan tool to OBD II systems  Check:  injection pump solenoids  electric feed pumps  fuel tank pressure  water sensors

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Cylinder Balance Test  Disable one injector at a time  Loosen injection line to disable injector  Engine speed should drop and the engine should idle roughly—if not, the cylinder is not firing

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Wear safety glasses and leather gloves Cylinder Balance Test

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Compression Test  Use a diesel compression gauge with a 600 psi (4134 kPa) range  Install in the injector or glow plug hole  Disconnect the fuel shutoff solenoid or disable the fuel system  Crank the engine and note the highest reading on the gauge  Compare to specifications  Typically psi ( kPa)

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Glow Plug Resistance-Balance  Unplug the wires to all the glow plugs  Measure the resistance of each glow plug and record your readings  Run the engine to operating temperature  Shut off the engine  Recheck the glow plug resistances  If a cylinder is not firing, the resistance of its glow plug will not increase as much as the resistance of the other glow plugs

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Pyrometer Balance Test  Pyrometer measures temperatures accurately  Probe temperature at each exhaust port  Each reading should be similar  A cool reading indicates that the cylinder is not firing

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Injection-Pressure Test  Uses special valves and a high- pressure gauge  Connect the tester between the pump and the injectors  Identifies:  opening pressure  nozzle leakage  injection line pressure balance  pump condition

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Injection-Pressure Tester Checks injection system operation while the system is still on engine

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Injector nozzle service  Glow plug service  Injection pump service

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Injector Nozzle Service  A bad injector usually causes the engine to miss  reduces engine power and causes knocking  nozzles can wear, become clogged, or be damaged

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Injector Substitution  Easy way to verify an injector problem  Install a known good injector for one being tested  If the cylinder fires, the old injector is faulty  If the engine still misses with the new injector, other problems exist

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Injector Removal  Never remove a component with the engine running—high-pressure fuel is a hazard!  Disconnect the battery for safety  Don’t bend or kink high-pressure injection lines during removal  Press-fit injectors may require a special tool for removal

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Note the position of all parts Injector Removal

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Impact Puller May be needed to remove press-fit injectors

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Injector Pop Tester Checks injector nozzle operation while the nozzle is out of the engine

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Injector Pop Testing Pump the handle while observing spray pattern, opening pressure, and leakage

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Opening Pressure  Note pressure reading when the nozzle opens  Compare to specifications  Typical opening pressure: 1700–2200 psi (12,000–15,000 kPa)  If opening pressure is not within specifications, rebuild or replace the injector

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Spray Patterns

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Injector Leakage  Maintain pressure about 300 psi (2000 kPa) below opening pressure  At this pressure, the nozzle should not leak or drip for 10 seconds

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Rebuilding Injectors  Disassemble  Clean  Inspect  Replace bad parts  injector shims may be used to increase opening pressure

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Rebuilding Injectors Inspect each part closely for carbon buildup, wear, or damage

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Diesel Injector Tool Kit Contains a soft brush, gauges, and other devices for injector rebuilding

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Organizing Tray Handy when servicing injectors

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Installing Injectors  Coat threads with antiseize compound  Use a new heat shield or seal  Screw into head by hand  Torque to specification  Reconnect injection line without bending it  Check for leaks (carefully) after starting

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Installing Injectors or Glow Plugs

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Glow Plug Service  Use a test light to check for voltage to the glow plugs during cycling  An inductive ammeter may be used to check current  low current may be caused by open glow plugs or supply circuit

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Glow Plug Resistance Test Check glow plug with an ohmmeter. Compare resistance to specifications.

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Glow Plug Replacement  Warning! Glow plugs may be hot!  Disconnect leads  Use a deep-well socket for removal  Coat glow plug threads with antiseize compound before installation  Screw into head by hand  Torque to specification

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Injection Pump Service  Most service is done by specialty shops with special tools and test stands  External gasket, seal, and solenoid repairs may be made in a general shop

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Injection Pump Test Stand Used to check injection pump operation

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only External Pump Repairs Leaks and faulty solenoids may be fixed without pump teardown

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Pump Removal  Set engine No. 1 piston at TDC  Observe pump timing marks  Disconnect battery  Remove injection lines, linkages, wires, and fasteners  Cap all lines  Remove pump

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Pump Removal Note the parts that must be disconnected before removal

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Parts Transfer This vacuum regulator valve must be reused on a new or rebuilt pump

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Installation  Align timing marks as you install pump  Torque fasteners and lines to specifications  Reconnect battery  Air bleeding may be necessary  The pump will be timed using various methods

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Adjustments  Injection pump timing  Cable/linkage adjustment  Curb idle speed  Cold idle speed  Maximum speed

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Injection Pump Timing Rotate the pump against the direction of rotation to advance timing; rotate the pump with the direction of rotation to retard timing

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Dial Indicator A dial indicator may be used to adjust timing on some vehicles

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Luminosity Meter Technician using a luminosity meter to detect combustion timing for adjustment

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Fuel Pressure Detector and Scope Transducer detects injection pulse

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Fuel Pressure Detector and Scope Low idle 1700 rpm, injection occurs sooner

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Cable/Linkage Adjustments

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Vacuum Valve Adjustment Carburetor angle gauge may be used to adjust the vacuum valve on this particular injection pump

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only External Adjustments

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Curb Idle Speed  Start engine and run to operating temperature  Connect a diesel tachometer  Adjust to specifications using the curb idle speed adjusting screw

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Diesel Tachometer Senses crankshaft damper position

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Cold Idle Speed  Usually performed on a hot engine  Connect a jumper wire from a battery feed to fast idle solenoid to raise engine speed  Raise engine speed to release solenoid plunger  Adjust to specifications, usually by turning solenoid plunger

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Cold Idle Speed Solenoid

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Maximum Speed  Limits highest attainable engine rpm  Position tachometer so that it can be read from driver’s seat  With the transmission in neutral or park and the brakes on, slowly press the accelerator to the floor  If maximum speed is not within specifications, turn adjusting screw on the injection pump

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Maximum Speed Adjustment

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Computerized Diesel Injection Service  Similar to other computer-controlled systems  Use self-diagnostics and scan tools  Use digital meters to check wiring, sensors and actuators