Engine Controls - System/component Tests Toyota Land Cruiser 70

INTRODUCTION

Note. California and Federal applies to installed emission equipment, which may be verified by underhood emission decal. California emissions may be available in other states. References to California models applies to California emission vehicles.

Before testing separate components or systems, perform procedures in the BASIC TESTING article. Since many computer-controlled and monitored components set a diagnostic trouble code if they malfunction, also perform procedures in the TESTS W/CODES article.

Note. Testing individual components does not isolate shorts or opens. Perform all voltage tests with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate wiring harness shorts or opens.

Note. When testing some systems, tachometer may be required. Tachometer must be connected to proper terminals. For tachometer connections, see IDLE SPEED & MIXTURE in the ADJUSTMENTS article.

Power & Ground Circuits

For testing of power/ground circuits, see procedures in the PIN VOLTAGE CHART S article. See ECM LOCATION table for identifying ECM mounting locations.

ECM LOCATION

Note. (Scheme 10)identifies ECM terminals which are used for performing tests on various components in this article.

Scheme 10

AIRFLOW METER

Note. Airflow meter may be referred to as Volume Airflow (VAF) meter or Mass Airflow (MAF) meter.

1. Turn ignition off. Disconnect electrical connector from airflow meter. Note airflow meter terminal identification. (Scheme 11)
2. Using ohmmeter, measure resistance between specified terminals. See the «AIRFLOW METER RESISTANCE SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. Replace airflow meter if resistance is not within specification.
3. To check airflow meter operation, ensure electrical connector is installed on airflow meter. Connect voltmeter leads to proper terminals on airflow meter with electrical connector installed. (Scheme 12)
4. Turn ignition on. Apply air into airflow meter and note voltage reading. (Scheme 12) While air is being applied, voltage reading should fluctuate. Replace airflow meter if voltage does not fluctuate. Remove voltmeter.

Scheme 11

Scheme 12

AIRFLOW METER RESISTANCE SPECIFICATIONS

CRANKSHAFT POSITION SENSOR

For checking crankshaft position sensor, see CRANKSHAFT POSITION SENSOR under IGNITION CHECKS (DISTRIBUTOR TYPE IGNITION SYSTEM) in the BASIC TESTING article.

EGR GAS TEMPERATURE SENSOR

1. Remove EGR gas temperature sensor from side of EGR valve. Place threaded end of sensor and thermometer in container of oil.
2. Attach ohmmeter to electrical terminals. Heat oil and note resistance at specified temperature. See «EGR GAS TEMPERATURE SENSOR SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. Replace EGR gas temperature sensor if resistance is not within specification.

EGR GAS TEMPERATURE SENSOR SPECIFICATIONS

ENGINE COOLANT TEMPERATURE (ECT) SENSOR

1. Ensure ignition is off. Disconnect electrical connector from ECT sensor. See «ENGINE COOLANT TEMPERATURE (ECT) SENSOR LOCATION»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. To verify wire colors for proper sensor identification, see wiring diagram in the WIRING DIAGRAMS article. NOTE: The ECT may be also identified using appropriate illustration in the «THEORY/OPERATION»(/toyota/land-cruiser/70-1984-2007/remont/theory-operation/#engine-controls-theory-operation) article.
2. Using ohmmeter, check resistance between ECT sensor electrical terminals. Resistance should be within specification at designated temperature. (Scheme 13) Replace ECT sensor if resistance is not within specification.

ENGINE COOLANT TEMPERATURE (ECT) SENSOR LOCATION

Scheme 13

KNOCK SENSOR

1. Knock sensor(s) are located on the cylinder block. (Scheme 14) Remove knock sensor from cylinder block before testing. See the REMOVE/INSTALL/OVERHAUL article.
2. Using ohmmeter, check that no continuity exists between electrical terminal of knock sensor and body of knock sensor. Replace knock sensor if continuity exists.

Scheme 14

PARK/NEUTRAL POSITION (PNP) SWITCH CIRCUIT

If problem exists with park/neutral position switch or circuit, a diagnostic trouble Code P1780 will be stored in the Engine Control Module (ECM). See the TESTS W/CODES article for accessing diagnostic trouble codes.

A/T Models

1. Disconnect electrical connector from park/neutral position switch, mounted on side of transmission or transaxle. Note terminal identification. (Scheme 15)
2. Using ohmmeter, check for continuity at specified terminals with gearshift in proper positions. See the «PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. If proper continuity cannot obtained, adjust switch. Replace switch if proper continuity cannot be obtained.

PARK/NEUTRAL POSITION SWITCH SPECIFICATIONS

Scheme 15

OXYGEN SENSOR FEEDBACK VOLTAGE TEST

Oxygen sensor feedback voltage test is not available. If problem exists with oxygen sensor, diagnostic trouble code will be stored in Engine Control Module (ECM). For trouble code diagnosis, see the TESTS W/CODES article.

Note. Diagnostic trouble Codes 21, 25, 26, 27 and 28 (some models) are oxygen sensor circuit codes. For diagnostic trouble code charts, see the TESTS W/CODES article.

OXYGEN SENSOR APPLICATION

OXYGEN SENSOR HEATER

1. A front oxygen sensor is used on exhaust pipe in front of catalytic converter and a rear oxygen sensor on exhaust pipe behind catalytic converter. Disconnect electrical connector from appropriate oxygen sensor and note oxygen sensor terminals. (Scheme 16)
2. Using ohmmeter, measure resistance between oxygen sensor terminals +B and HT. (Scheme 16) Replace oxygen sensor if resistance is not within specs. See the «OXYGEN SENSOR HEATER RESISTANCE SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table.

OXYGEN SENSOR HEATER RESISTANCE SPECIFICATIONS

Scheme 16

PICK-UP COILS

See PICK-UP COIL AIR GAP and PICK-UP COIL RESISTANCE under IGNITION CHECKS (DISTRIBUTOR TYPE IGNITION SYSTEM) in the BASIC TESTING article.

THROTTLE POSITION SENSOR

1. Turn ignition off. Disconnect electrical connector from Throttle Position Sensor (TPS) on throttle body. Note terminal identification. (Scheme 17) NOTE: Some models require that vacuum be applied to throttle opener before checking TPS. See «TPS RESISTANCE SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table.
2. Insert specified thickness feeler gauge between throttle stop screw and throttle lever and check resistance or continuity. See the «TPS RESISTANCE SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. Replace or adjust TPS if not within specification.

Scheme 17

TPS RESISTANCE SPECIFICATIONS

VEHICLE SPEED SENSOR

1. Vehicle speed sensor is located on transmission/transaxle and contains a 3-wire connector. Connect voltmeter and battery voltage to vehicle speed sensor terminals. (Scheme 18)
2. While rotating vehicle speed sensor shaft, ensure voltage changes from zero to at least 11 volts. Voltage should change 4 times per revolution of the shaft. Replace vehicle speed sensor if voltage does not change as specified.

Scheme 18

FUEL PUMP ELECTRONIC CONTROL UNIT

See FUEL DELIVERY under FUEL SYSTEM.

CIRCUIT OPENING RELAY

1. Ensure ignition is off. Remove circuit opening relay. See «CIRCUIT OPENING RELAY LOCATION»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. NOTE: Circuit opening relay may also be identified using appropriate illustration in the «THEORY/OPERATION»(/toyota/land-cruiser/70-1984-2007/remont/theory-operation/#engine-controls-theory-operation) article or wire color. See wiring diagram in the WIRING DIAGRAMS article. CIRCUIT OPENING RELAY LOCATION Application Relay Location Land Cruiser In Relay Box Behind Driver's Side Kick Panel
2. Using ohmmeter, check continuity between specified terminals. (Scheme 19)
3. Check circuit opening relay operation by applying battery voltage and ground and checking continuity between specified terminals. (Scheme 20) Replace circuit opening relay if defective.

Scheme 19

Scheme 20

EFI MAIN RELAY

1. Ensure ignition is off. Remove EFI main relay. See «EFI MAIN RELAY LOCATION»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. NOTE: The EFI main relay may also be identified using appropriate illustration in the «THEORY/OPERATION»(/toyota/land-cruiser/70-1984-2007/remont/theory-operation/#engine-controls-theory-operation) article or wire color. See wiring diagram in the WIRING DIAGRAMS article. EFI MAIN RELAY LOCATION Application Location Land Cruiser Fuse/Relay Box Near Driver's Side Front Corner Of Engine Compartment
2. Using ohmmeter, check continuity between specified terminals. (Scheme 21)
3. Check EFI main relay operation by applying battery voltage and ground and checking continuity between specified terminals. (Scheme 22) Replace EFI main relay if defective.

Scheme 21

Scheme 22

FUEL PUMP RELAY

1. Ensure ignition is off. Remove fuel pump relay. See «FUEL PUMP RELAY LOCATION»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. NOTE: Fuel pump relay may be identified using appropriate illustration in the «THEORY/OPERATION»(/toyota/land-cruiser/70-1984-2007/remont/theory-operation/#engine-controls-theory-operation) article or wire color. See wiring diagram in the WIRING DIAGRAMS article. FUEL PUMP RELAY LOCATION Application Location Land Cruiser Driver's Side Of Engine Compartment On Fender, Near Fenderwell & Contains Black 4-Wire Connector
2. Using ohmmeter, check continuity between specified terminals. (Scheme 23)
3. Check fuel pump relay operation by applying battery voltage and ground and checking continuity between specified terminals. (Scheme 24) Replace fuel pump relay if defective.

Scheme 23

Scheme 24

See CIRCUIT OPENING RELAY under RELAYS.

See EFI MAIN RELAY under RELAYS.

Fuel Pump Pressure

For fuel pump pressure testing, see FUEL PRESSURE in the BASIC TESTING article.

Fuel Pump Resistance & Operation

1. Disconnect electrical connector for fuel pump. See «FUEL PUMP ELECTRICAL CONNECTOR LOCATION»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. FUEL PUMP ELECTRICAL CONNECTOR LOCATION Application Connector Location Land Cruiser Under Cover, Below Second Seat
2. To check fuel pump resistance, using ohmmeter, measure fuel pump resistance between specified terminals on connector or fuel pump. (Scheme 25) Replace fuel pump if resistance is not within specification. See «FUEL PUMP RESISTANCE»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) Ohms @ 68°F (20°C) table. FUEL PUMP RESISTANCE - Ohms @ 68°F (20°C) Application Ohms Land Cruiser.2-3.0 CAUTION: When checking fuel pump operation, DO NOT apply battery voltage to fuel pump for more than 10 seconds or fuel pump may be damaged. When checking fuel pump operation, keep fuel pump away from battery as far as possible.
3. To check fuel pump operation, apply battery voltage and ground on specified terminals on connector or fuel pump. (Scheme 25) DO NOT apply battery voltage to fuel pump for more than 10 seconds. Keep fuel pump away from battery as far as possible. Replace fuel pump if fuel pump fails to operate.

Scheme 25

See FUEL PUMP RELAY under RELAYS.

Fuel Pump Resistor

1. Ensure ignition is off. Disconnect fuel pump resistor electrical connector. See «FUEL PUMP RESISTOR LOCATION»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. (Scheme 26)
2. Using ohmmeter, measure resistance between fuel pump resistor electrical terminals. Replace fuel pump resistor if resistance is not within specification. See «FUEL PUMP RESISTOR SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table.

FUEL PUMP RESISTOR LOCATION

FUEL PUMP RESISTOR SPECIFICATIONS

Scheme 26

Fuel Injectors

1. Ensure ignition is off. Disconnect electrical connector at fuel injector. Using ohmmeter, measure resistance between fuel injector electrical terminals. Replace fuel injector if resistance is not within specification. See «FUEL INJECTOR RESISTANCE SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table.
2. To check fuel injector spray pattern and volume, remove fuel injector. See the REMOVE/INSTALL/OVERHAUL article. Disconnect fuel hose from fuel filter outlet. Use Delivery Hose (09268-41045) to install fuel injector between fuel filter and fuel pressure regulator. (Scheme 27)and (Scheme 28).
3. Place fuel injector into a clean graduated container. Place vinyl tube on end of fuel injector to prevent fuel spillage. NOTE: Scan tester is used to operate the fuel pump or by applying battery voltage to electric fuel pump.
4. Use scan tester to operate the fuel pump or apply battery voltage to electric fuel pump to pressurize the fuel system. See FUEL PRESSURE in the «BASIC TESTING»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-basic-testing) article.
5. Connect fuel injector tester to fuel injector for 15 seconds. Use Fuel Injector Tester (09842-30070).
6. Measure fuel injector volume and check spray pattern. Test each fuel injector 2-3 times. Replace fuel injector if volume is not as specified. See the «FUEL INJECTOR VOLUME SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. NOTE: Ensure difference between fuel injector volume on all fuel injectors is within specification. See FUEL INJECTOR VOLUME SPECIFICATIONS table.
7. Disconnect fuel injector tester. Ensure fuel leakage from end of fuel injector is one drop or less in specified time. See the «FUEL INJECTOR LEAKAGE SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. Replace fuel injector if leakage exceeds specified amount.

FUEL INJECTOR RESISTANCE SPECIFICATIONS

FUEL INJECTOR VOLUME SPECIFICATIONS

FUEL INJECTOR LEAKAGE SPECIFICATIONS

Scheme 27

Scheme 28

Note. Fuel pressure control system may also be referred to as fuel pressure-up system.

Fuel Pressure Control System

1. Fuel pressure control system uses a fuel pressure control Vacuum Switching Valve (VSV). Fuel pressure control VSV is supplied voltage through EFI main relay.
2. The Engine Control Module (ECM) will activate VSV by controlling ground circuit for approximately 90-180 seconds when restarting engine at normal operating temperature. Locate and remove fuel pressure control VSV. See «FUEL PRESSURE CONTROL VSV LOCATION»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. NOTE: Fuel pressure control VSV may also be identified using appropriate illustration in the «THEORY/OPERATION»(/toyota/land-cruiser/70-1984-2007/remont/theory-operation/#engine-controls-theory-operation) article or wire color. See wiring diagram in WIRING DIAGRAMS article. FUEL PRESSURE CONTROL VSV LOCATION Application Location Land Cruiser Front Lower Side Of Intake Manifold, Near Dipstick
3. Using ohmmeter, check resistance and for continuity between fuel pressure control VSV electrical terminals. Replace fuel pressure control VSV if no continuity exists or resistance is not within specification. See «FUEL PRESSURE CONTROL VSV RESISTANCE SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table.
4. Ensure no continuity exists between each electrical terminal and fuel pressure control VSV body. Replace fuel pressure control VSV if continuity exists between electrical connector and fuel pressure control VSV body.
5. Check fuel pressure control VSV operation by applying air pressure to designated area and checking air passage, and then applying battery voltage and ground and retesting. (Scheme 29) Replace fuel pressure control VSV if defective.

FUEL PRESSURE CONTROL VSV RESISTANCE SPECIFICATIONS

Scheme 29

Fuel Cut System

1. When checking fuel cut system, engine RPM must be monitored.
2. Scan tester is connected to data link connector No. 3 for monitoring engine RPM. For connecting of scan tester, see appropriate application under IDLE SPEED & MIXTURE in the «ADJUSTMENTS»(/toyota/land-cruiser/70-1984-2007/remont/adjustments/#engine-controls-adjustments) article. CAUTION: Some tachometers may not be compatible with ignition system. Consult tachometer manufacturer before connecting tachometer to system. To avoid possible damage to ignitor and/or coil, DO NOT allow tachometer terminal to become grounded.
3. Start and warm engine to normal operating temperature. Ensure all accessories are off. Gradually increase engine RPM to maintain at least specified engine speed. See «FUEL CUT SYSTEM TESTING SPECIFICATION»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. FUEL CUT SYSTEM TESTING SPECIFICATION Application Engine RPM Land Cruiser 3500
4. Using stethoscope, check for fuel injector operating sound. Ensure when throttle lever is released, fuel injector stops operating momentarily (fuel cut RPM) and then resumes operating (fuel return RPM).
5. Ensure fuel cut RPM (if available) and fuel return RPM are within specification. See «FUEL CUT SYSTEM SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. Shut engine off. Remove test equipment.

FUEL CUT SYSTEM SPECIFICATIONS (1)

IDLE AIR CONTROL (IAC) VALVE

1. Listen for clicking sound at IAC valve immediately after engine is shut off. NOTE: IAC valve is located on throttle body.
2. If no clicking sound is heard, check IAC valve resistance and operation. To check IAC valve resistance, ensure ignition is off. Disconnect electrical connector from IAC valve. Note IAC valve terminals. (Scheme 30)
3. Using ohmmeter, measure resistance between specified terminals. See «IAC VALVE RESISTANCE SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. Replace IAC valve if resistance is not within specification. IAC VALVE RESISTANCE SPECIFICATIONS Terminals Ohms B1 To S1 Or S3 10-30 B2 To S2 Or S4 10-30
4. To check IAC valve operation, remove IAC valve. Note IAC valve terminal identification. (Scheme 30)
5. Apply battery voltage to terminals B1 and B2. (Scheme 30) Repeatedly ground terminals in sequence and ensure IAC valve closes and opens. See «IAC VALVE GROUNDING SEQUENCE»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. (Scheme 31)and (Scheme 32). Replace IAC valve if defective. IAC VALVE GROUNDING SEQUENCE Application Terminal Grounding Sequence To Close IAC Valve S1-S2-S3-S4-S1 To Open IAC Valve S4-S3-S2-S1-S4
6. If IAC valve resistance is correct and operates correctly, check wiring between Engine Control Module (ECM) and IAC valve. See wiring diagram in the WIRING DIAGRAMS article.
7. ECM is located above glove box.

Scheme 30

Scheme 31

Scheme 32

IGNITION SYSTEM

Note. For basic ignition checks, see the BASIC TESTING article.

See KNOCK SENSOR under ENGINE SENSORS & SWITCHES.

EXHAUST GAS RECIRCULATION (EGR) SYSTEM TEST

Note. EGR systems contain different components depending on application. (Scheme 34) When testing EGR system and components, use proper illustration to determine component location.

Note. When performing EGR system test, it will be necessary to monitor engine RPM by using tachometer or scan tester depending on model application. For tachometer or scan tester connections, see IDLE SPEED & MIXTURE in the ADJUSTMENTS article.

1. Ensure EGR vacuum modulator filter(s) are clean and in good condition. Clean filter(s) with compressed air (if necessary). NOTE: EGR vacuum modulator filter(s) must be installed with coarse side facing upward, away from EGR vacuum modulator.
2. Using "T" connector, install vacuum gauge in line with vacuum hose on top of EGR valve. Start engine. Ensure engine runs idles smoothly to ensure proper seating of EGR valve. NOTE: The EGR system components can be checked with engine coolant temperature less than minimum temperature and engine at specified engine RPM.
3. Operate engine with engine coolant temp. less than minimum temperature and at specified RPM. See the «EGR TESTING SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. No vacuum reading should be obtained.
4. Warm engine to normal operating temperature. Operate engine at specified engine RPM again. See «EGR TESTING SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. Ensure a low vacuum reading is now obtained.
5. Disconnect vacuum hose from port "R" of EGR vacuum modulator. (Scheme 33)
6. Using additional hose, connect port "R" of EGR vacuum modulator directly to intake manifold. High vacuum reading should be obtained at specified engine RPM. See «EGR TESTING SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. NOTE: Engine should misfire due to large amounts of exhaust gas being injected into intake manifold.
7. Remove vacuum hose and reconnect original vacuum hose to EGR vacuum modulator.
8. To check EGR valve operation, remove and plug hose at EGR valve. Using vacuum pump, apply vacuum directly to EGR valve with engine idling. Engine should run rough or stall. If EGR system does not operate as described, each individual component should be tested.

Scheme 33

EGR TESTING SPECIFICATIONS

Scheme 34

EGR VACUUM MODULATOR

Note. When testing EGR vacuum modulator, it will be necessary to monitor engine RPM by using tachometer or scan tester depending on model application. For tachometer or scan tester connections, see IDLE SPEED & MIXTURE in the ADJUSTMENTS article.

1. Mark vacuum hose locations and disconnect vacuum hoses from EGR vacuum modulator. Block ports "P" and "R" on EGR vacuum modulator. (Scheme 33) NOTE: Ports "P" and "R" are the double ports on side of EGR vacuum modulator. Port "Q" is single port on side of EGR vacuum modulator.
2. Apply air pressure to port "Q". (Scheme 33) Air should pass freely through air filter side of EGR vacuum modulator.
3. Start and operate engine at specified RPM. See «EGR VACUUM MODULATOR TESTING SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. Repeat test procedures in steps 1) and 2). Strong resistance of airflow should be felt. Replace EGR vacuum modulator if resistance is not felt. Reconnect vacuum hoses to proper locations.

EGR VACUUM MODULATOR TESTING SPECIFICATIONS

EGR VACUUM SWITCHING VALVE (VSV)

Note. When testing EGR VSV, use proper illustration to determine component location. (Scheme 34)

1. Disconnect electrical connector from EGR VSV, located below air intake chamber. Using ohmmeter, check resistance between EGR VSV electrical terminals.
2. Replace EGR VSV if resistance is not within specification. See «EGR VSV RESISTANCE SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. Ensure no continuity exists between each electrical terminal and EGR VSV body. Replace EGR VSV if continuity exists between any electrical terminal and VSV body.
3. Apply air pressure to port "G" without battery connected. (Scheme 35) Air pressure should flow through port "E". Connect battery voltage and ground to EGR VSV electrical terminals. (Scheme 35) Apply air pressure to port "G". Air pressure should not flow from port "E". Replace EGR VSV if defective.

EGR VSV RESISTANCE SPECIFICATIONS

Scheme 35

FUEL EVAPORATION SYSTEM

Note. Fuel evaporation systems contain different components depending on application. (Scheme 34) When testing fuel evaporation system components, use proper illustration to determine component location.

EVAP Thermal Vacuum Valve

1. Drain cooling system. Remove EVAP TVV located in coolant passage on cylinder head. (Scheme 34)
2. Use cool water to cool threaded end of EVAP TVV to less than 113°F (45°C). Apply air pressure to lower port on EVAP TVV. Ensure EVAP TVV is closed and air passes out air filter, located on top of EVAP TVV.
3. Heat water to greater than 147°F (64°C). Apply air pressure to lower port on EVAP TVV. Ensure EVAP TVV is open and air passes through upper port and not through air filter. Replace EVAP TVV if defective. Apply thread sealant to threads of EVAP TVV and reinstall. Fill cooling system.

Charcoal Canister

1. Disconnect hoses from charcoal canister. Check for clogged filter and/or stuck check valve by applying low air pressure to port "A". (Scheme 36) Ensure air flows freely from other ports on charcoal canister.
2. Apply low air pressure to port "B" while holding port "C" closed. (Scheme 36) Ensure air flows freely from port "A". Replace charcoal canister if defective.
3. To clean charcoal canister filter, apply 43 psi (3 kg/cm 2 ) air pressure to port "A" while holding port "B" closed. Ensure no activated carbon comes out of charcoal canister. DO NOT attempt to wash out charcoal canister.

Scheme 36

EVAP Check Valve

1. Remove EVAP check valve from vacuum hose to EVAP Vacuum Control Valve (VCV). The EVAP VCV is located on bracket, below air intake chamber, near engine oil dipstick. (Scheme 34)
2. Apply air pressure to Orange colored side of EVAP check valve. Air should pass through EVAP check valve. Apply air pressure to Black colored side of EVAP check valve. Air should not pass through EVAP check valve. Replace EVAP check valve if defective.

EVAP Vacuum Control Valve

1. Warm engine to normal operating temperature. With engine idling, ensure no suction exists on union pipe at EVAP Vacuum Control Valve (VCV). (Scheme 37)
2. Gradually increase engine to 3000 RPM. Ensure suction now exists on union pipe. If suction does not exist, remove EVAP VCV. Using vacuum pump, apply 2.8 in. Hg of vacuum to port "S" on EVAP VCV. (Scheme 37)
3. Apply air pressure to port "Y". Ensure air flows from port "Z". Remove vacuum pump. Apply air pressure to port "Y". Ensure air does not flow from port "Z". Replace EVAP VCV if defective and recheck operation. If EVAP VCV is okay, check EVAP Vacuum Switching Valve (VSV).

Scheme 37

POSITIVE CRANKCASE VENTILATION (PCV)

1. Remove PCV valve. Attach hose to PCV valve. Blow air from cylinder head side of PCV valve. Ensure air passes easily through PCV valve.
2. Blow air from intake manifold side of PCV valve. Ensure air passes through PCV valve with some restriction. Replace PCV valve if valve does not function as described.

DASHPOT CONTROL SYSTEM

1. Warm engine to normal operating temperature. Ensure idle speed is correct. See IDLE SPEED & MIXTURE in the «ADJUSTMENTS»(/toyota/land-cruiser/70-1984-2007/remont/adjustments/#engine-controls-adjustments) article.
2. With engine idling, open throttle valve on valve body until throttle lever separates from end of dashpot. Gradually release throttle valve and note dashpot setting RPM when throttle lever contacts dashpot.
3. Dashpot setting RPM should be 1900-2500 RPM. If dashpot setting RPM is incorrect, shut engine off. Loosen lock nut and rotate stopper bolt. (Scheme 38)
4. Repeat step 2) until proper adjustment is obtained. Tighten lock nut. To check throttle body Vacuum Transmitting Valve (VTV) operation, operate engine at 3500 RPM. Release throttle. Ensure engine returns to idle in a few seconds.

Scheme 38

THROTTLE OPENER

1. Warm engine to normal operating temperature. Ensure idle speed is correct. See IDLE SPEED & MIXTURE in the «ADJUSTMENTS»(/toyota/land-cruiser/70-1984-2007/remont/adjustments/#engine-controls-adjustments) article.
2. Disconnect/plug vacuum hose at throttle opener, located on side of throttle body. Start engine and note engine speed. Engine speed should be within specs. See «THROTTLE OPENER SPECIFICATIONS»(/toyota/land-cruiser/70-1984-2007/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table.
3. If engine speed is not within specification, replace throttle body. Shut engine off. Reinstall vacuum hose on throttle opener. Start engine and ensure engine returns to proper idle speed.

THROTTLE OPENER SPECIFICATIONS

See also:
• BASIC TESTING
• TESTS W/CODES
• ADJUSTMENTS
• THEORY/OPERATION
• ECM LOCATION
• CIRCUIT OPENING RELAY
• EFI MAIN RELAY
• FUEL PUMP RELAY
• KNOCK SENSOR