Download ELECTRONIC FUEL INJECTION

ELECTRONIC FUEL
INJECTION
DIAGNOSIS AND REPAIR
TOPICS WE ARE GOING TO COVER
GENERAL UNDERSTANDING OF TYPICAL FUEL
INJECTION SYSTEMS AND COMPONENTS USED ON
TODAYS VEHICLES.
TROUBLESHOOTING E.F.I.(ELECTRONIC FUEL
INJECTION) SYSTEMS.
STUDY SEVERAL E.F.I. WIRING SCHEMATICS.
TOOLS USED IN DIAGNOSING FUEL INJECTION
RELATED PROBLEMS
COMPONENTS OF A FUEL INJECTED
SYSTEM
COMPONENTS OF THE FUEL SYSTEM THAT
HAVE ACTUAL MECHANICAL CONNECTION
WITH FUEL
FUEL PUMP AND STRAINER
FUEL FILTER
FUEL LINES
FUEL INJECTORS
FUEL PRESSURE REGULATOR
FUEL PUMP AND STRAINER
A FUEL PUMP IS A
STEPPER MOTOR THAT
PUMPS FUEL TO THE
VEHICLES ENGINE.
SOME FUEL
PRESSURES CAN
EXCEED 65 P.S.I.
FUEL PUMPS ARE
ACTIVATED
ELECTRONICALLY.
FUEL PUMP AND STRAINER
COMMON TO BE
PLACED IN FUEL TANK
COOLED BY THE FUEL
IN THE FUEL TANK
NO MAINTENANCE
REQUIRED
ALL PUMPS HAVE A
CHECK BALL INSIDE TO
MAINTAIN FUEL
PRESSURE WHILE
VEHICLE IS OFF.
FUEL PUMP AND STRAINER
A NORMAL OPERATING
FUEL PUMP WILL MAKE
A SLIGHT WHINNING
NOISE.
FUEL PUMP CAN BE
HEARD BY REMOVING
THE FUEL TANK FILLER
CAP
EXCESSIVE WHINNING
CAN BE A SIGN OF
FUTURE PUMP
FAILURE
FUEL PUMP AND STRAINER
THE IGNITION ON
SIGNAL FROM THE
IGNITION SWITCH WILL
PRIME THE FUEL
PUMP, THIS WILL
ALLOW THE FUEL
SYSTEM TO ACHIEVE
ENOUGH FUEL
PRESSURE FOR A
QUICK ENGINE START
FUEL PUMP AND STRAINER
THE STRAINER IS A
FILTER THAT CLIPS TO
THE BOTTOM OF THE
FUEL PUMP
FILTERS ALL FOREIGN
MATERIAL COLLECTED
AT THE BOTTOM OF
THE FUEL TANK FROM
ENTERING FUEL
SYSTEM
QUIZ
WHERE IS THE FUEL PUMP USUALLY LOCATED?
HOW IS THE FUEL PUMP ACTIVATED?
WHAT COOLS THE FUEL PUMP?
WHAT PURPOSE DOES THE STRAINER SERVE?
WHAT IS A QUICK WAY TO DETERMINE IF THE FUEL
PUMP IS WORKING?
HOW DOES THE FUEL SYSTEM STAY UNDER
PRESSURE WHEN THE VEHICLE IS TURNED OFF?
FUEL FILTER
FILTERS CONTAMINANTS (DIRT AND RUST) IN FUEL
SYSTEM AS FUEL TRAVELS TO THE ENGINE
CONNECTED IN THE FUEL SUPPLY LINE
ALL FUEL FILTERS HAVE AN INLET AND AN OUTLET
ALL FUEL FILTERS NEED TO BE INSTALLED
CORRECTLY, IF INSTALLED BACKWARDS VEHICLE
WILL NOT RUN PROPERLY
FUEL FILTER
REPLACEMENT OF A FUEL FILTER IS PART OF
REGULAR MAINTENANCE ON A VEHICLE
FUEL FILTER
IF A FUEL FILTER IS NOT REPLACED REGULARLY
(DEPENDING ON MANUFACTURER RECOMMENDED
REPLACEMENT INTERVAL) IT COULD BECOME
CLOGGED AND CAUSE RESTRICTION IN FUEL
FLOW
FUEL FILTER
FUEL LINES
FUEL LINES ARE STEEL, RUBBER AND PLASTIC
NYLON
MAKE CERTAIN THE REPLACEMENT LINE IS RATED
TO HANDLE THE PRESSURES OF THE SYSTEM
FUEL LINES
ALWAYS USE PRECAUTION WHEN ROUTING FUEL
LINES, KEEP THEM AWAY FROM EXHAUST SYSTEM
QUIZ
IN WHICH LINE IS THE FUEL FILTER SITUATED IN?
HOW COULD A FUEL FILTER BE INSTALLED
INCORRECTLY, AND WHAT WOULD HAPPEN TO THE
VEHICLE?
WHAT THREE MATERIALS ARE USED IN FUEL LINE
FABRICATION?
WHAT PRECAUTIONS SHOULD BE USED WHEN
ROUTING FUEL LINES DURING REPLACEMENT?
FUEL INJECTORS
FUEL INJECTOR IS AN ELECTRONICALLY CONTROLLED VALVE
IT IS SUPPLIED WITH PRESSURIZED FUEL FROM YOUR FUEL
PUMP
IT OPENS AND CLOSES MANY TIMES PER SECOND
FUEL INJECTORS
WHEN THE INJECTOR IS
ENERGIZED, AN
ELECTROMAGNET MOVES A
PLUNGER THAT OPENS THE
VALVE THIS ALLOWS THE
PRESSURIZED FUEL TO
SQUIRT OUT THROUGH A
TINY NOZZLE.
FUEL INJECTORS
SOME VEHICLE HAVE ONE OR TWO INJECTORS
THAT FEED THE ENTIRE SYSTEM, AND OTHERS
HAVE AN INJECTOR FOR EACH CYLINDER
THE AMOUNT OF FUEL SUPPLIED TO THE ENGINE
IS DETERMINED BY THE AMOUNT OF TIME THE
INJECTOR IS OPEN (injector on time)
FUEL INJECTORS
T.B.I = THROTTLE BODY INJECTION HAS ONE OR
TWO INJECTORS
M.P.I = MULTI PORT INJECTION HAS AN INJECTOR
FOR EACH CYLINDER, THE INJECTORS ARE
MOUNTED ON A FUEL RAIL.
FUEL INJECTORS
FUEL INJECTORS ARE MOUNTED DIRECTLY IN THE
INTAKE MANIFOLD SO THAT THE FUEL SPRAYS
DIRECTLY AT THE INTAKE VALVES
FUEL INJECTORS
CARBON CAN CAUSE INJECTORS TO
BECOME CLOGGED AND CAUSE ENGINE
MISFIRES
FUEL INJECTORS
INJECTOR PURGING CLEANS AWAY CARBON FROM
INJECTOR PINTLE AND RESTORES ORIGINAL
INJECTOR SPRAY PATTERN WHICH RETURNS
ORIGINAL ENGINE PERFORMANCE
FUEL INJECTORS
FUEL INJECTORS CAN BE TESTED WITH A NOID
LIGHT, AN OHMETER, OR WITH A SCOPE
INJECTORS MAKE A TICKING SOUND EVERYTIME
THEY ARE OPENED AND CLOSED
FUEL PRESSURE REGULATOR
FUEL PRESSURE REGULATOR KEEPS A
PREDETERMINED AMOUNT OF PRESSURE IN FUEL
RAIL AND RETURNS THE REMAINING FUEL TO THE
FUEL TANK
FUEL PRESSURE REGULATOR
PRESSURE IS CONTROLED FROM
DIAPHRAGM THAT IS EXPOSED TO
MANIFOLD VACCUM
QUIZ
WHAT CAUSES THE INJECTOR TO OPEN?
WHAT HAPPENS WHEN THE INJECTOR OPENS?
WHAT SUBSTANCE IS RESPONSIBLE FOR
CLOGGING INJECTORS?
WHAT DOES THE TERM T.B.I. MEAN AND HOW MANY
INJECTORS DOES IT HAVE?
WHAT DOES THE TERM M.P.I MEAN AND HOW MANY
INJECTORS DOES IT HAVE?
WHERE IS THE INJECTOR LOCATED?
WHAT IS THE PURPOSE OF THE FUEL PRESSURE
REGULATOR?
COMPONENTS OF A FUEL INJECTED
SYSTEM
ELECTRICAL COMPONENTS OF A FUEL SYSTEM
IGNITION SWITCH
FUEL PUMP RELAY
WIRING AND CONNECTORS
INERTIA SWITCH ( SOME FORD VEHICLES )
IGNITION SWITCH
THE IGNITION SWITCH IS LOCATED IN THE
STEERING COLUMN AND IS SWITCHED ON BY
TURNING THE KEY
IT IS USUALLY CONNECTED TO THE BACK OF THE
KEY CYLINDER
IGNITION SWITCH
THE IGNITION SWITCH GIVES SIGNAL TO THE VEHICLES
COMPUTER INFORMING IT OF WHAT DEMAND IS BEING
MADE.
DEMANDS THAT ARE MADE TO THE COMPUTER FROM THE
IGNITON SWITCH ARE:
KEY ON,ENGINE OFF( VOLTAGE TO MOST OF THE VEHICLES ELECTRICAL
SYSTEMS
START ( CRANKING ) ACTIVATES STARTER
KEY OFF ( SWITCH IS OPEN AND CUTS OFF POWER TO MOST ELECTRICAL
SYSTEMS
ACCESSORY (POWER TO LIMITED COMPONENTS)
IGNITION SWITCH
THERE IS ALWAYS BATTERIE POWER CONNECTED
TO ONE SIDE OF THE IGNITION SWITCH
WHEN THE IGNITION KEY IS TURNED BY THE
VEHICLES DRIVER THE VOLTAGE SIGNAL TRAVELS
THROUGH THE SWITCH TO THE CORRESPONDING
CIRCUIT, DEPENDING ON THE DEMAND FROM THE
SWITCH.
BY PROBING THE IGNITION SWITCHS CIRCUITS A
TEST LIGHT CAN BE USED TO TEST THE
PERFORMANCE OF THE IGNITION SWITCH
IGNITION SWITCH
COMMON PROBLEMS THAT CAN OCCUR FROM A
DEFECTIVE IGNITION SWITCH
* VEHICLE NO START OR CRANK CONDITION
* NO POWER IN VEHICLE
* MAJOR DRIVEABILITY PROBLEMS
* FIRE DAMAGE
IGNITION SWITCH
QUIZ
WHAT DOES THE IGNITON SWITCH DO?
WHERE IS THE IGNITION SWITCH TYPICALLY
LOCATED?
WHAT ARE SOME COMMON PROBLEMS THAT CAN
OCCUR FROM A MALFUNCTIONING IGNITION
SWITCH?
HOW DO YOU TEST AN IGNITION SWITCH?
WHAT VOLTAGE SHOULD YOU SEE AT THE SUPPLY
SIDE OF THE IGNITION SWITCH?
WHAT DEMANDS DO THE IGNITION SWITCH MAKE?
FUEL PUMP RELAY
A RELAY IS EQUIVALENT TO A SWITCH.
WHEN GROUNDED, A RELAY CHANGES THE
CIRCUIT FROM TO OPEN TO CLOSED
RELAYS ARE COMMONLY FOUND ON WIPER
MOTOR CIRCUITS, FAN CIRCUITS, FUEL PUMP
CIRCUITS.
FUEL PUMP RELAY
THE IGNITION SWITCH SENDS A SIGNAL THAT
ACTIVATES THE FUEL PUMP RELAY
TYPICALLY THE PCM ( POWERTRAIN CONTROL
MODULE) RECIEVES THE IGNITION SIGNAL TO
EITHER POWER OR GROUND THE FUEL PUMP
RELAY WHICH WILL COMPLETE THE FUEL PUMP
RELAY CIRCUIT
FUEL PUMP RELAY
FUEL PUMP RELAY IS ON THE SUPPLY SIDE OF THE
ELECTRICAL CIRCUIT OF THE FUEL PUMP
THEY ARE LOCATED IN A VARIETY OF LOCATIONS
DEPENDING ON THE MAKE AND MODEL OF
VEHICLE
SEVERAL COMMON LOCATIONS ARE
* UNDER THE HOOD ON THE FIRE WALL
* IN THE FUSE PANEL ( UNDER HOOD OR DASH)
* IN THE POWER DISTRIBUTION CENTRE
FUEL PUMP RELAY
THE OIL PRESSURE SWITCH IS USED FOR START UP
IN CASE OF FUEL PUMP RELAY FAILURE (GM)
FUEL PUMP RELAY
WHEN THE KEY IS FIRST TURNED ON, THE
IGNITION SWITCH SENDS A SIGNAL TO THE PCM.
THE PCM WILL SIGNAL THE RELAY TO ALLOW
CURRENT FLOW TO THE FUEL PUMP FOR 3
SECONDS.
THE 3 SECOND PUMP PRIME IS TO ASSIST ON
START UP
THE PRIMING WILL BRING FUEL PRESSURE UP TO
SPEC.
THIS ALLOWS FOR PROPER FUEL SPRAY FROM
THE INJECTORS ON CRANKING TO ENSURE
SHORTER CRANKING AND FASTER STARTING
FUEL PUMP RELAY
THE FUEL PUMP RELAY ALLOWS CURRENT FLOW
ON CRANKING SIGNAL FROM THE IGNITION
SWITCH
BY PROBING THE FUEL PUMP RELAYS PRONGS
WITH A TEST LIGHT YOU CAN DIAGNOSE VOLTAGE
SIGNALS AT THE RELAY
FUEL PUMP RELAY
IT IS TYPICAL TO HAVE VOLTAGE ON TWO OF THE WIRES IN
THE RELAY CIRCUIT.
HOOKING UP A TEST LIGHT TO THE FUEL PUMP RELAY AND
MANUALLY GROUNDING THE RELAY YOU WILL DIAGNOSE
THE OPERATION OF THE FUEL PUMP RELAY
FUEL PUMP RELAY
WHEN A RELAY IS GROUNDED IT WILL MAKE A
SINGLE TICKING NOISE
WHEN TURNING THE KEY ON, YOU CAN HEAR THE
FUEL PUMP COME ON FOR SEVERAL SECONDS
QUIZ
WHAT IS A RELAY?
WHAT NOISE WILL A PROPERLY FUNCTIONING
RELAY MAKE?
WHAT IS THE BEST WAY TO TEST A RELAY?
WHAT FUNCTION DOES THE RELAY SERVE?
WHERE WOULD YOU USUALLY FIND A RELAY?
WHAT IS A TYPICAL VOLTAGE FOUND AT THE
SUPPLY SIDE OF THE RELAY?
WHAT TOOLS CAN BE USED TO TEST A RELAY?
WIRING AND CONNECTORS
WHEN REPAIRING WIRING ALWAYS USE PROPER
TECHNIQUE
* ALWAYS USE SOLDER
* CONNECT THE WIRES IN PROPER FASHION
* ALWAYS USE HEAT SHRINK
WIRING AND CONNECTORS
IT IS CRUCIAL TO USE SOLDER ON ALL REPAIRS TO
ELIMINATE ANY CHANCE THAT CORROSION
DEVELOPS
CORROSION COULD DEVELOP OVER ANY PERIOD
OF TIME AND CREATE MAJOR VEHICLE PROBLEMS
CORROSION WILL CREAT A VOLTAGE DROP WHICH
WOULD RESULT IN LOWER VOLTAGE AVAILABLE IN
THE FUEL CONTROL CIRCUIT
THE LOWER VOLTAGE COULD RESULT IN
DRIVEABILITY PROBLEMS OR NO START
CONDITIONS
WIRING AND CONNECTORS
FUEL CONTROL WIRING CIRCUIT IS TYPICALLY
CONNECTED WITH THE FUEL GAUGE WIRING
CIRCUIT.
THE FUEL CONTROL WIRING CIRCUIT IS LOCATED
THROUGH OUT THE ENTIRE VEHICLE.
THE FUEL CONTROL CIRCUIT TRAVELS FROM THE
BATTERIE, UNDER THE HOOD, INTO THE
PASSENGER COMPARTMENT AND INTO THE FUEL
TANK
INERTIA SWITCH
IT IS A SWITCH USED ON FORD VEHICLES
IT IS A SAFETY FUEL CUT OFF SWITCH THAT
OPENS THE FUEL CONTROL CIRCUIT TO SHUT OFF
FUEL SUPPLY FROM THE FUEL TANK DURING AN
ACCIDENT
INERTIA SWITCH
VIBRATIONS CAUSE THE SWITCH TO OPEN
THE INERTIA SWITCH CAN CAUSE TRICKY DIAGNOSIS TO
TECHNICIANS THAT DO NOT PERFORM THE PROPER
DIAGNOIS PROCEDURES
EXCESSIVE STEREO VOLUME CAN CREAT VIBRATRIONS THAT
WILL TRIGGER THE INERTIA SWITCH WHICH WILL STALL THE
VEHICLE
QUIZ
WHAT COMPANY INVENTED AND USES THE INERTIA
SWITCH
WHAT IS THE PURPOSE OF THE INERTIA SWITCH
WHAT TRIGGERS THE INERTIA SWITCH
WHAT SHOULD BE DONE ON ALL WIRING REPAIRS
WHERE IS THE WIRING FOR THE FUEL CONTROL
CIRCUIT
WHAT SYSTEM CIRCUIT RUNS ALONG SIDE WITH
THE FUEL CONTROL CIRCUIT
DIAGNOSTIC TOOLS
DIAGNOSING TODAYS FUEL INJECTED VEHICLES
NEEDS TO BE PERFORMED BY A TRAINED
TECHNICIAN WITH EXPERIENCE USING A WIDE
VARIETY OF DIFFERENT DIAGNOSTIC TOOLS
DURING DIAGNOSIS IT IS COMMON TO USE MORE
THAN ONE TOOL AT A TIME
INFORMATION IS CRITICAL TO ASSIST THE
TECHNICIAN ON A PROPER DIAGNOSTIC
PROCEDURE
DIAGNOSTIC TOOLS
SEVERAL TOOLS THAT ARE USED TO PERFORM A
PROPER DIAGNOSTIC ARE
* TEST LIGHT
* SCAN TOOL
* ELECTRONIC LAB SCOPE (D.S.O)
* FUEL PRESSURE TESTER
* DVOM MULTI METER
* NOID LIGHT AND LOGIC PROBES
* AUTOMOTIVE STETHOSCOPE
DIAGNOSTIC TOOLS
TEST LIGHT HOOKS UP TO AN ELECTRICAL CIRCUIT
TO CHECK FOR POWER OR CONTINUITY
DIAGNOSTIC TOOLS
TEST LIGHTS CAN BE USED TO CHECK SIGNAL,
SUPPLY AND GROUNDS
TEST LIGHTS ARE QUICK AND EASY TO USE
DIAGNOSTIC TOOLS
SCAN TOOL COMMUNICATES WITH THE VEHICLES
COMPUTER
SCAN TOOLS PERFORM MANY DIFFERENT
NECESSARY FUNCTIONS
DIAGNOSTIC TOOLS
SCAN TOOLS CAN BE PLUGGED INTO THE
VEHICLE, HOWEVER SOME NEWER MODELS ARE
WIRELESS
ALL FUEL INJECTED VEHICLES HAVE A DATA LINK
CONNECTOR (D.L.C) THIS IS WHERE THE SCAN
TOOL PLUGS INTO THE VEHICLE.
ALL VEHICLES MADE AFTER 1993 HAVE THE D.L.C
LOCATED UNDER THE DASH ON THE DRIVER SIDE.
DIAGNOSTIC TOOLS
SEVERAL FUNCTIONS THE SCAN TOOL PERFORMS
* CODE RETRIEVAL
* READ VEHICLE DATASTREAM
* PERFORM RECORD AND PLAYBACK OF
DATASTREAM
*REFLASH COMPUTERS AND MODULES
*IDLE RELEARN AND COMPUTER RELEARN
*STORE VEHICLE SPECS AND TSB
INFORMATION
DIAGNOSTIC TOOLS
A SCAN TOOL CAN RETRIEVE DIAGNOSTIC CODES
STORED IN THE VEHICLES COMPUTER
FUEL INJECTION PROBLEMS WILL TURN ON THE
S.E.S. LIGHT TO WARN THE DRIVER OF A PROBLEM
A SCAN TOOL CAN ERASE DIAGNOSTIC CODES TO
TURN OFF THE S.E.S.(SERVICE ENGINE SOON
LIGHT) IN THE VEHICLES DASH
DIAGNOSTIC TOOLS
A SCAN TOOL WILL DISPLAY ACTUAL LIVE
DATASTREAM
THE TECHNICIAN USES THIS INFORMATION TO
DIAGNOSE POTENTIAL PROBLEMS
DIAGNOSTIC TOOLS
LAB SCOPES ARE CALLED D.S.O ( DIGITAL
STORAGE OSCILLOSCOPE)
D.S.O ARE A TOOLS USED TO VISUALLY SEE THE
VOLTAGE IN REAL TIME
D.S.O CAN DISPLAY BOTH VOLTAGES AND
FREQUENCIES AS WAVEFORMS
DIAGNOSTIC TOOLS
SCOPES ARE VERY EFFECTIVE AT FINDING
GLITCHES IN SENSORS.
GLITCHES CANNOT BE FOUND BY USING A SCAN
TOOL OR A DVOM
DIAGNOSTIC TOOLS
A TECHNICIAN NEEDS PROPER TRAINING TO USE
THE LABSCOPE TO ITS FULL POTENTIAL
THERE IS A LOT OF INFORMATION THAT CAN BE
DISPLAYED ON A LABSCOPE AND IF INTERPRETED
PROPERLY, THE TECHNICIAN CAN DIAGNOSE
MANY PROBLEMS
DIAGNOSTIC TOOLS
SOME D.S.O’S HAVE A LIBRARY OF KNOWN GOOD
WAVEFORMS FOR COMPARISON DURING
DIAGNOSIS
SOME D.S.O’S HAVE A DATABASE OF ELECTRICAL
WIRING SCHEMATICS AND TEST PROCEDURES
DIAGNOSTIC TOOLS
MOST SCOPES HAVE DUAL TRACE OR MULTIPLE
TRACE CAPABILITIES TO ALLOW THE TECHNICIAN
TO VIEW MORE THAN ONE WAVEFORM AT A TIME
DIAGNOSTIC TOOLS
A FUEL PRESSURE TESTER IS A GAUGE THAT
READS THE FUEL PRESSURE
A FUEL PRESSURE TESTER KIT CONTAINS A
VARIETY OF HOSES AND CONNECTORS, THE
HOSES AND CONNECTORS USED ARE DEPENDANT
ON THE SYSTEM BEING TESTED
DIAGNOSTIC TOOLS
MOST VEHICLES FUEL SYSTEMS HAVE A FUEL
PRESSURE TEST PORT.
THE TEST PORT IS A SCHRADER VALVE
DIAGNOSTIC TOOLS
THE FUEL PRESSURE TESTER CONNECTS TO THE
TEST PORT ( SCHRADER VALVE ) AND THE
PRESSURE WILL BE INDICATED ON THE GAUGE
YOU CAN TEST KEY ON ENGINE OFF PRESSURE
AND KEY ON ENGINE RUNNING PRESSURE
DIAGNOSTIC TOOLS
SOME FUEL SYSTEMS DO NOT HAVE A FUEL
PRESSURE TEST PORT
HOSES ARE USED TO CONNECT THE PRESSURE
TESTER INTO THE SYSTEM
THESE SYSTEM TAKE MORE TIME AND WORK TO
TEST FUEL PRESSURE
DIAGNOSTIC TOOLS
ELECTRICAL DIAGNOSTICS IS A MAJOR PART OF
DIAGNOSING FUEL INJECTION AUTOMOTIVE
PROBLEMS
A DIGITAL VOLT OHMMETER (DVOM) MULTI METER
MEASURES ELECTRICAL VALUES
DIAGNOSTIC TOOLS
ELECTRICAL VALUES THAT ARE TYPICALLY
MEASURED WITH AN AUTOMOTIVE DVOM ARE
* VOLTAGE
* AMPERAGE
* RESISTANCE
*FREQUENCY
DIAGNOSTIC TOOLS
SEVERAL VALUES MEASURED WITH THE DVOM
ARE:
SUPPLY VOLTAGE
VOLTAGE DROP
BATTERY VOLTAGE
TOTAL RESISTANCE
CIRCUIT RESISTANCE
UNWANTED RESISTANCE
CURRENT
CURRENT DRAW
DIAGNOSTIC TOOLS
OTHER VALUES THAT CAN BE MEASURED BY A
DVOM OTHER THAN A ELECTRICAL VALUES
* TEMPERATURE
* RPM
DIAGNOSTIC TOOLS
NOID LIGHTS AND LOGIC PROBES ARE TYPICALLY
USED TO CHECK FOR INJECTOR PULSES
A NOID LIGHT PLUGS INTO THE WIRING HARNESS
IN PLACE OF A FUEL INJECTOR
EVERYTIME THE E.C.M. PULSES THE INJECTOR
THE NOID LIGHT WILL FLASH.
DIAGNOSTIC TOOLS
LOGIC PROBES CAN ALSO BE USED TO CHECK
FOR INJECTOR PULSE
LOGIC PROBES REAL VALUE IS IT CAN DETECT
ELECTRONIC PULSES
LOGIC PROBES CAN CHECK FOR TWO THINGS,
HIGH VOLTAGE AND LOW VOLTAGE
DIAGNOSTIC TOOLS
LOGIC PROBES ARE SAFE TO USE ON MODULES
AND SENSORS BECAUSE IT HAS AN INTERNAL
HIGH RESISTANCE
DIAGNOSTIC TOOLS
AUTOMOTIVE STETHOSCOPES ARE USED TO
ISOLATE NOISES
STETHOSCOPES CAN BE USED TO LISTEN FOR
INJECTOR PULSES AND FUEL PUMP OPERATION