1986 TOYOTA SUPRA fuel pressure
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TROUBLESHOOTING
HINT: Before troubleshooting the turbocharger, first check the engine itself. (Valve clearance, engine com-
pression, ignition timing etc.)
Check intake air system, and repair or replace parts
as necessary. (See page
EG±144)
1. TURBOCHARGING PRESSURE TOO
LOW
2. RESTRICTED INTAKE SYSTEM
6. ERRATIC TURBOCHARGER
OPERATION
3. LEAK IN INTAKE AIR SYSTEM
4. RESTRICTED EXHAUST SYSTEM
5. LEAK IN EXHAUST SYSTEM
INSUFFICIENT ACCELERATION, LACK OF POWER OR EXCESSIVE FUEL
CONSUMPTION
(Possible Cause) Check Procedure and Correction Method)
Check turbocharging pressure. (See page EG±144)
Turbocharging pressure:
61±75 kPa
(062±0.76 kgf/cm
2,
8.8±10.8 psi)
If the pressure is below specifications, begin
diagnosis from item 2.
Check intake air system, and repair or replace parts
as necessary. (See page
EG±144)
Check intake air system, and repair or replace parts
as necessary. (See page
EG±144)
Check intake air system, and repair or replace parts
as necessary. (See page
EG±144)
Check rotation of turbine shaft. If it does not
turn or turns with a heavy drag, replace the
turbocharger assembly.
Check axial and radial play of turbine shaft.
(See page EG±158)
Maximum axial play : 0.110 mm (0.0045 in.)
Maximum radial play : 0.162 mm (0.0064 in.)
If the play is greater than maximum, replace
the turbocharger assembly. EG±142
± ENGINETURBOCHARGER SYSTEM (2JZ±GTE)
Page 34 of 878
Trouble Area
Malfunction
Indicator
Lamp*
1
Memory*2
See page
Trouble Area
Normal
Mode
Test
Mode
Memory
See page
Open or short in heater circuit of main heated oxygen
sensor
Main heated oxygen sensor heater
ECM
ON
N.A.
Main heated oxygen sensor circuit
Mi h td
ON
ON
EG±525
Main heated oxygen sensor
ON
ON
Main heated oxygen sensor
Open or short in engine coolant temp. sensor circuit
Engine coolant temp. sensor
ECM
ON
ON
EG±530
Open or short in intake air temp. sensor circuit
Intake air temp. sensor
ECM
ON
ON
EG±532
Open or short in Main heated oxygen sensor circuit
Oen or short in Main heated oxygen sensor circuit
Main heated oxygen sensor
Main heated oxygen sensor
Ignition system
gy
ECM
Open or short in injector circuit
Oen or short in injector circuit
Fuel linepressure (injector leak blockage) ON ON EG 534
Fuel line pressure (injector leak, blockage)
Mechanical system malfunction (skipping teeth ofONONEG±534 Mechanical system malfunction (skipping teeth of
timing belt)
timing belt)
Ignition system
Ignition system
Compression pressure (foreign object caught in valve)
Compression pressure (foreign object caught in valve)
M i fl t (i itk)
Mass air flow meter (air intake)
ECM
ECM
*1, 2: See page EG±502
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTINGEG±497
Page 35 of 878
DTC
No.
Number of
MIL BlinksCircuitDiagnostic Trouble Code Detecting Condition
(a) Engine speed: Below 950 rpm
(b) Engine coolant temp.: 80°C (176°F) or more
(2 trip dectection logic)*3
Engine speed varies by more than 20 rpm over the preceding
crank angle period during a period of 25 sec. or more
under conditions (a) and (b):
(1) Open or short in heater circuit of sub heated oxygen sensor
for 0.5 sec. or more
(2) Main heated oxygen sensor signal is 0.45 V or more and
sub heated oxygen sensor signal is 0.45 V or less under
conditions (a) ~ (c):
(2 trip dectection logic)*3
(a) Engine coolant temp.: 80°C (176°F) or more
(b) Engine speed: 1,5000 rpm or more
(c) Accel. pedal: Fully depressed for 2 sec. or more
Open or short in mass air flow meter circuit for 3 sec. or more
with engine speed less than 3,000 rpm
Open or short in turbo pressure sensor circuit for 0.5 sec. or
more
Open or short in BARO sensor circuit for 0.5 sec. or more
Sub Heated
Oxygen Sensor
Signal
Air±Fuel
Ratio Rich
Malfunction
Mass Air Flow
Meter Circuit
Turbo Pressure
Malfunction
Turbo Pressure
Sensor Circuit
Barometric
Pressure
Sensor Circuit
(c) Engine speed: 2,4000 rpm or more
(a) Mainfold absolute pressure: 200 kPa (2.0 kgf/cm2,
29 psi) or more
(b) Thottle valve opening angle: 20° or more
All conditions below are detected continuously for 2 sec. or more:
*3: See page EG±503. EG±498
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING
Page 36 of 878
Trouble Area
Malfunction
Indicator
Lamp*
1
Memory*2
See page
Trouble Area
Normal
Mode
Test
Mode
Memory
See page
Open or short in injector circuit
Fuel line pressure (injector leak, blockage)
Mechanical system malfunction (skipping teeth of
timing belt)
Ignition system
Compression pressure (foreign object caught in valve)
Mass air flow meter (air intake)
ECM
ON
ON
EG±534
Open or short in heater circuit of sub heated oxygen
sensor.
Sub heated oxygen sensor
ECM
ON
N.A.
Open or short in sub heated oxygen sensor circuit
Sub heated oxygen sensor
ECM
ON
ON
EG±540
Open or short in mass air flow meter circuit
Mass air flow meter
ECM
ON
N.A.
EG±544
Actuator (for waste gate valve)
Short in VSV for waste gate valve circuit
ECM
ON
N.A.
EG±546
Open or short in turbo pressure sensor circuit
Turbo pressure sensor
ECM
ON
ON
EG±549
ECM
ON
ON
EG±549
*1, 2: See page EG±502.
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTINGEG±499
Page 41 of 878
FAIL±SAFE CHART
If any of the following codes is detected, the ECM enters fail±safe mode.
DTC No. Fail±Safe Operation Fail±Safe Deactivation Conditions
14
Fuel cut
6 IGF signals detected in 6 consecutive
ignitions
16 Torque control prohibited Returned to normal condition
22
THW is fixed at 80°C (176°F)
Returned to normal condition
24 THA is fixed at 20°C (68°F) Returned to normal condition
31
Volume of air flowing is measured by turbo pressure
Sensor to determine injection volume and ignition
Timing
Returned to normal condition
34
Fuel cut
Returned to normal condition
Turbo
Turbo
Pressure Fuel cut Returned to normal condition
35 Sensor
35
BARO
Sensor
Atmospheric pressure is fixed at
101.3 kPa (760 mmHg, 29.92 inVHg)
Returned to normal condition
41
VTA1 is fixed at closed throttle position
The following must each be repeated at
least 2 times consecutively:
0.1 V VTA1 0.95 V
IDL: ON
47
VTA2 is fixed at wide open throttle
Position
The following must be repeated at least 2
times consecutively
0.1 V VTA2 0.95 V
52 Max. timing retardation IG switch OFF
53 Max. timing retardation Returned to normal condition
55 Max. timing retardation IG switch OFF
Back±Up Function
If there is trouble with the program in the ECM and the ignition signals (IGT) are not output from the microcomput-
er, the ECM controls fuel injection and ignition timing at predetermined levels as a back±up function to make
it possible to continue to operate the vehicle.
Furthermore, the injection duration is calculated from the starting signal (STA) and the throttle position signal
(IDL). Also, the ignition timing is fixed at the initial ignition timing, 10
°BTDC, without relation to the engine speed.
HINT: If the engine is controlled by the back±up function, the malfunction indicator lamp lights up to warn the
driver of the malfunction but the diagnostic trouble code is not output. EG±504
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING
Page 45 of 878
(See page
IG±26)
Check fuel pressure.
Proceed to page EG±264 and continue to
troubleshoot.
(1) Be sure that there is enough fuel in the tank.
(2) Turn ignition switch ON.
(3) Using SST, connect terminals FP and +B of
data link connector 1.
SST 09843±18020
Check that there is pressure in the hose from the fuel
filter.
If there is fuel pressure, you will hear the sound of fuel
flowing.
Never make a mistake with the terminal con-
nection position as this will cause a malfunc-
tion.
Check for spark.
Proceed to page IG±21 and continue to trou-
bleshoot.
Proceed to matrix chart of problem symptoms
on page EG±514.
(1) Remove ignition coil (See page IG±26)
(2) Remove spark plug.
(3) Install the spark plug to the ignition coil, and connect
the ignition coil connector.
(4) Ground the spark plug.
Check if spark occurs while engine is being cranked.
To prevent excess fuel being injected from the injectors
during this test, don't crank the engine for more than 1
Ð 2 seconds at a time.
EG±508± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING
Page 51 of 878
Suspect area
See page
Symptom
Engine does not crank
No initial combustion
No complete combustion
Engine cranks normally
Cold engine
Hot engine
Incorrect first idle
High engine idle speed
Low engine idle speed
Rough idling
Hunting
Hesitation/Poor acceleration
Muffler explosion (after fire)
Surging
Soon after starting
After accelerator pedal depressed
After accelerator pedal released
During A/C operation
When shifting N to D
Does not
start
Difficult to
start
Poor Idling
Engine Stall
Poor
Driveability
Back up power source circuitECM power source circuitPark/neutral position switch circuitSwitch condition signal circuitEGR systemStarter signal circuitMass air flow meter circuitInjector circuitIAC valve circuitFuel pump control circuitA/C signal circuit (Compressor circuit)Turbo control circuitVSV circuit for fuel Pressure ControlCompressionSpark plugIgnition signal circuit (Spark test)Starter and Starter relayIgnition coilEngine control module (ECM)Theft deterrent ECUA/T faulty
EG±544EG±559EG±564EG±571EG±574EG±576EG±581EG±583EG±586EG±568EG±595EG±589AC±62ST±3
,
12
IG±21IG±23IG±22EG±9AT2±101BE±123IN±35
MATRIX CHART OF PROBLEM SYMPTOMS
When the malfunction code is not confirmed in the diagnostic trouble code check and the problem still can not
be confirmed in the basic inspection, proceed to this matrix chart and troubleshoot according to the numbered
order given below. EG±514
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING
Page 71 of 878
DTC 25 26 Air±Fuel Ratio Lean Rich Malfunction
CIRCUIT DESCRIPTION
See EG±525 for the circuit description.
DTC No. Diagnostic Trouble Code Detecting Condition Trouble Area
(1) Main heated oxygen sensor voltage is
0.45 V or less (lean) for 90 sec. under
conditions (a) and (b):
(2 trip detection logic)*
2
(a) Engine coolant temp.: 70°C (158°F)
or more
(b) Engine speed: 1,500 rpm or more
Open or short in main heated oxygen
sensor circuit
Main heated oxygen sensor
Ignition system
ECM
25
(2) Engine speed varies by more than 20 rpm
over the preceding crank angle period
during a period of 25 sec. or more under
conditions (a) and (b):
(2 trip detection logic).*
(a) Engine speed: Below 950 rpm
(b) Engine coolant temp.: 80°C
(176°F) or
more
Open and short in injector circuit
Fuel line pressure (injector leak, blockage)
Mechanical system malfunction
(skipping teeth of timing belt)
Ignition system
Compression pressure (foreign object
caught in valve)
Mass air flow meter (air intake)
ECM
26
Engine speed varies by more than 20 rpm over
The preceding crank angle period during a
Period of 25 sec. or more under conditions (a)
And (b):
(2 trip detection logic).*
(a) Engine speed: Below 950 rpm
(b) Engine coolant temp.: 80°C
(176°F) or
more
Open and short in injector circuit
Fuel line pressure (injector leak, blockage)
Mechanical system malfunction
(skipping teeth of timing belt)
Ignition system
Compression pressure (foreign object
caught in valve)
Mass air flow meter (air intake)
ECM
*: See page EG±503. EG±534
± ENGINE2JZ±GTE ENGINE TROUBLESHOOTING