Page 103 of 192

Injection Timing Control Valve
The injection timing control valve is built into the electronic fuel
injection pump. It controls the timer piston to change the fuel injec-
tion timing.
The timing control valve is a solenoid valve located in the line
between high-pressure chamber and low-pressure chamber. It
changes fuel pressure in the high-pressure chamber.
When current ¯ows through the solenoid (the solenoid turns ON),
the timing control valve opens, advancing fuel injection timing.
When current does not ¯ow through it, the timing control valve
closes, retarding injection timing.
The ECM emits an ON-OFF duty signal. The longer the OFF-
duration, the greater the advance angle. The longer the
ON-duration, the greater the retard angle. This means that chang-
ing the ON-OFF duty ratio makes it possible to achieve an optimal
advance angle and accurately control fuel injection timing.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
ACT INJ TIMG+Engine: After warming up
+Air conditioner switch: ``OFF''
+Shift lever: ``N''
+No-loadIdle þ9.5 to þ12.0É
2,000 rpm þ10.0 to þ15.5É
INJ TIMG C/V+Engine: After warming up, idle the engine. Approx. 50%
ECM TERMINALS AND REFERENCE VALUE
Remarks: Speci®cation data are reference values and are measured between each terminal andV43(ECCS
ground) with a voltmeter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
104
11 0L/WInjection timing control
valveEngine is running.
(Warm-up condition)
Idle speedBATTERY VOLTAGE
(11 - 14V)
SEF729V
Engine is running.(Warm-up condition)
Engine speed is 2,000 rpm.BATTERY VOLTAGE
(11 - 14V)
SEF730V
SEF638S
TROUBLE DIAGNOSIS FOR ``F/INJ TIMG F/B'' (DTC 21)
EC-101
Page 104 of 192

ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble Code
No.Malfunction is detected when ....Check Items
(Possible cause)
21+Injection timing feedback system does not operate
properly. (This system consists essentially of ECM,
injection timing control valve and needle lift sensor.)+Harness or connectors
[Injection timing control valve, needle lift sensor,
crankshaft position sensor (TDC) circuits]
+Injection timing control valve
+Needle lift sensor
+Crankshaft position sensor (TDC)
+Air in fuel line
DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE
Note: If both DTC 21 and 34 or 47 are displayed, perform
TROUBLE DIAGNOSIS FOR DTC 34 or 47. (See EC-126
or EC-144.)
1) Turn ignition switch ``ON'' and select ``DATA MONITOR''
mode with CONSULT.
2) Start engine and warm it up to normal operating tem-
perature.
3) Run engine for 2 seconds at 3,000 rpm. Return engine
speed to idle, then increase to 3,000 rpm under no load.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Start engine and warm it up to normal operating tem-
perature.
2) Run engine for 2 seconds at 3,000 rpm. Return engine
speed to idle, then increase to 3,000 rpm under no load.
3) Turn ignition switch ``OFF'', wait at least 5 seconds and
then turn ``ON''.
4) Perform ``Diagnostic Test Mode II (Self-diagnostic
results)'' with ECM.
Note: If a malfunction occurs intermittently, conduct suitable
driving pattern for 10 minutes. This makes it possible to
determine DTC.
SEF751V
TROUBLE DIAGNOSIS FOR ``F/INJ TIMG F/B'' (DTC 21)
Injection Timing Control Valve (Cont'd)
EC-102
Page 105 of 192
TEC430
TROUBLE DIAGNOSIS FOR ``F/INJ TIMG F/B'' (DTC 21)
Injection Timing Control Valve (Cont'd)
EC-103
Page 106 of 192

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK FOR AIR IN FUEL FILTER.
1. Move priming pump up and down to
purge air from fuel ®lter.
2. Perform ``DIAGNOSTIC TROUBLE
CODE CONFIRMATION PROCE-
DURE''.
NG
cOK
INSPECTION END
CHECK POWER SUPPLY.
1. Turn ignition switch ``OFF''.
2. Disconnect injection timing control valve
harness connector.
3. Turn ignition switch ``ON''.
4. Check harness continuity between ter-
minal
V2and ground with CONSULT or
tester.
Voltage: Battery voltage
OK
cNG
Check the following.
+Harness connectors
M51,F6
+Electronic fuel injection
pump harness connector
F3
+10A fuse
+Harness for open or
short between injection
timing control valve and
fuse
If NG, repair harness or
connectors.
CHECK OUTPUT SIGNAL CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Disconnect ECM harness connector.
3. Check harness continuity between ter-
minal
V1and ECM terminals104,
11 0.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Check the following.
+Electronic fuel injection
pump harness connector
F3
+Harness for open or
short between injection
timing control valve and
ECM
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
CHECK COMPONENT
(Injection timing control valve).
Refer to ``COMPONENT INSPECTION''
on next page.
OK
cNG
Replace injection timing
control valve.
Disconnect and reconnect harness connec-
tors in the circuit. Then retest.
Trouble is not ®xed.
Check ECM pin terminals for damage and
check the connection of ECM harness con-
nector. Reconnect ECM harness connector
and retest.
INSPECTION END
SEF670V
SEF685V
SEF754V
SEF755V
.
.
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``F/INJ TIMG F/B'' (DTC 21)
Injection Timing Control Valve (Cont'd)
EC-104
Page 107 of 192
COMPONENT INSPECTION
Injection timing control valve
1. Reconnect injection timing control valve harness connector.
2. Disconnect electronic fuel injection pump harness connector.
3. Check resistance between terminals
V3andV7.
Resistance: Approximately 11W[at 20ÉC (68ÉF)]
If NG, replace injection timing control valve.
SEF686V
TROUBLE DIAGNOSIS FOR ``F/INJ TIMG F/B'' (DTC 21)
Injection Timing Control Valve (Cont'd)
EC-105
Page 128 of 192

Needle Lift Sensor (NLS)
The needle lift sensor is built into the No. 1 injection nozzle. Its
piezoelectric element senses changes in fuel injection timing
caused by fuel temperature, etc. This change of fuel injection tim-
ing is sent as a pulse signal to the ECM.
ECM TERMINALS AND REFERENCE VALUE
Remarks: Speci®cation data are reference values and are measured between each terminal andV43(ECCS
ground) with a voltmeter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
34 W Needle lift sensorEngine is running.
(Warm-up condition)
Idle speedApproximately 0V
SEF718V
Engine is running.(Warm-up condition)
Engine speed is 2,000 rpm.Approximately 0V
SEF719V
ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble Code
No.Malfunction is detected when ....Check Items
(Possible Cause)
34+An improper signal from the sensor is sent to ECM.+Harness or connectors
(The sensor circuit is open or shorted.)
+Needle lift sensor
+Air in fuel line
+Clogging No. 1 injection nozzle
SEF604S
Terminal
Piezoelectric element
TROUBLE DIAGNOSIS FOR ``NEEDLE LIFT SEN'' (DTC 34)
EC-126
Page 146 of 192

Crankshaft Position Sensor (TDC)
The crankshaft position sensor (TDC) monitors engine speed by
means of signals from the sensing plate (with two protrusions)
installed to the crankshaft pulley. The datum signal output is
detected at ATDC 70É and sent to the ECM. The sensor signal is
used for fuel injection control and fuel injection timing control.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
CKPSzRPM (TDC)+Tachometer: Connect
+Run engine and compare tachometer indication with the CONSULT
value.Almost the same speed as the
CONSULT value.
ECM TERMINALS AND REFERENCE VALUE
Remarks: Speci®cation data are reference values and are measured between each terminal andV43(ECCS
ground) with a voltmeter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
40
44LCrankshaft position sensor
(TDC)Engine is running.
(Warm-up condition)
Idle speedApproximately 0V
SEF720V
Engine is running.(Warm-up condition)
Engine speed is 2,000 rpm.Approximately 0V
SEF721V
47
52B/WCrankshaft position sensor
(TDC) groundEngine is running.(Warm-up condition)
Idle speedApproximately 0V
ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble Code
No.Malfunction is detected when ....Check Items
(Possible Cause)
47+An improper signal from the sensor is detected by
ECM during engine running and cranking.+Harness or connectors
(The sensor circuit is open.)
+Crankshaft position sensor (TDC)
SEF615S
TROUBLE DIAGNOSIS FOR ``CRANK POS SEN (TDC)'' (DTC 47)
EC-144
Page 192 of 192
ADJUSTMENT RESISTOR
Resistance [at 25ÉC (77ÉF)] kW0.2 - 15.0
INJECTION TIMING CONTROL VALVE
Resistance [at 20ÉC (68ÉF)]WApproximately 11
ELECTRIC GOVERNOR
Resistance [at 23ÉC (73ÉF)]W0.68
CRANKSHAFT POSITION SENSOR (TDC)
Resistance [at 25ÉC (77ÉF)] kWApproximately 0.8 - 1.2
GLOW PLUG
Resistance [at 25ÉC (77ÉF)]W0.8
ACCELERATOR POSITION SENSOR
Throttle valve conditionsResistance kW
[at 25ÉC (77ÉF)]
Completely closed Approximately 0.5
Partially open 0.5 - 4
Completely open Approximately 4
FUEL TEMPERATURE SENSOR
Temperature ÉC (ÉF) Resistance kW
þ20 (þ4) 13.67 - 16.37
20 (68) 2.306 - 2.568
60 (140) 0.538 - 0.624
80 (176) 0.289 - 0.344
SERVICE DATA AND SPECIFICATIONS (SDS)
Inspection and Adjustment (Cont'd)
EC-190
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