1987 TOYOTA CELICA Service Repair Manual

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Problem
Engine will not star-t/
hard to start
(cranks OK)
Rough idle or stalls
Engine hesitates/
poor acceleration
Muffler explosion
(after fire) all the
time
Engine backfires
Poor fuel economy
Engine overheats
TROUBLESHOOTING
Possible causes
Incorrect ignition timing
Ignition problems
0 Ignition coil
. (7M-GTE)
Igniter
. (7M-GE)
Distributor
(7M-GTE)
Cam position sensor
l High-tension cords
Ignition wiring disconnected
or broken
Spark plugs faulty
Ignition wiring faulty
Incorrect ignition timing
Ignition problems
0 Ignition coil
. I7M-GTE)
Igniter
. (7M-GE)
Distributor
(7M-GTE)
Cam position sensor
0 High-tension cords
Spark plugs faulty
Ignition wiring faulty
Incorrect ignition timing
Incorrect ignition timing
Incorrect ignition timing
Spark plugs faulty
Incorrect ignition timing
Incorrect ignition timing Remedy
Reset timing
lrkpect coil
Inspect igniter
Inspect distributor
Inspect cam position sensor
Inspect high-tension cords
Inspect wiring
Inspect plugs
Inspect wiring
Reset timing
Inspect coil
Inspect igniter
Inspect distributor
Inspect cam position sensor
Inspect high-tension cords
Inspect plugs
Inspect wiring
Reset timing
Reset timing
Reset timing
Inspect plugs
Reset timing
Reset timing =
Page-.. :
-
EM-17
IG-10 or 14
IG-17
IG-11
IG-1%
IG-6 or 13
IG-7
EM-l 7
IG-10 or 11
IG-17
IG-I 1
IG-18
IG-6 or 13
IG-7
EM-l 7
EM-1 7

IQ-4
IGNITION SYSTEM - Ignition System Circuit
IGNlTlON SYSTEM CIRCUIT
7M-GE, Ignition Switch lanitian Cnil
AM2 30A
Fusible Link
MAIN 2.OL
(MA)
~“. _._. _ _..
AM29~2
I “i!l A II
I
(MS)
I
Spark Plug l-1 II
R Igniter
1
7M-GTE
I
Ignition Switch
AM2 30A
Fusible Link
MAIN 2.OL
Battery IG2
To Tachometer
1 f
Cam Position
Sensor
r--1
G2 IGT
NE
IGdA
NO
IGdB f
To Tachome:
n Spark Plug
Igniter
: I=
B
I=
Ignition Coil
It08
ELECTRONIC SPARK ADVANCE (ESA)
The ECU is programmed with data for optimum ignitio
timing under any and all operating conditions. Using dat
provided by sensors which monitor various engine func
tions (rpm,
intake air volume, eng. temperature, etc.) th
microcomputer (ECU) triggers the spark at precisely th
right instant.

IGNITION SYSTEM - On-Vehicle Inspection (7M-GE)
IO-6 *
-. ON-VEHICLE INSPECTION (7M43E)‘;
SPARK TEST --
CHECK THAT SPARK OCCURS
(a) Disconnect high-tension cord from the distributor.
(b) Hold the end about 12.5 mm (0.49 in.) from body of
vehicle.
(G) See if spark occurs while engine is being cranked.
NOTE: To prevent gasoline from being injected from
injectors during this test, crank the engine for no more
than l-2 seconds at a time.
If the spark does not occur, perform the test as follows:
SPARK TEST
1
NO
,‘.
CHECK CONNECTION OF IGNITION COIL, BAD
Connect securely.
IGNITER AND DISTRIBUTOR CONNECTORS c
OK
CHECK RESISTANCE OF HIGH-TENSION
CORDS (See page IG-6) ’ BAD
Replace the cord(s).
OK
CHECK POWER SUPPLY TO IGNITION COIL
1. Ignition switch turn to ON.
2. Check that there is battery voltage at
ignition coil positive I+) terminal. Check wiring between ignition switch to
BAD
switch to ignition coil.
OK
CHECK RESISTANCE OF IGNITION COIL
(See page IG-10) 9
BAD Replace the ignition coil.
*
OK
1 , , 1
CHECK RESISTANCE OF DISTRIBUTOR
SIGNAL GENERATOR (PICK UP .COIL)
Resistance: 140 - 180 sz
OK BAD Replace the distributor.
m
CHECK AIR GAP OF DISTRIBUTOR
Air Gap: Each 0.2 - 0.4 mm
(0.008 - 0.016 in.) BAD
Replace the distributor.
L
OK
CHECK IGt SIGNAL FROM ECU
(See pages FI-51, 70) BAD
Check wiring between ECU and distributor,
only then try another ECU.
OK
t ,
TRY ANOTHER IGNITER
1 i

IGNlTliiN SYSTEM - On-Vehicle Inspection (7M-GE)
It059 ‘6
IG059
INSPECTiON OF HIGH-TENSION CORDS
1. REMOVE HIGH-TENSION CORDS
(a) Disconnect the throttle body.
l Disconnect the air cleaner hose.
l Remove the throttle body bracket.
0 Disconnect the throttle cables or accelerator con-
necting rod.
l Disconnect the PCV hose.
0 Remove the four bolts and pick up the throttle
body.
(b) Carefully remove the high-tension cords by their rub-
ber boots from the spark plugs.
CAUTION: Pulling on or bending the cords ma)
damage the conductor inside.
2. INSPECT HIGH-TENSION CORD RESISTANCE
Using an ohmmeter, measure the resistance without dis-
connecting the cap.
Maximum resistance: 25 kS2 per cord
If resistance exceeds maximum, check the terminals.
If necessary, replace the high-tension cord and/or dis-
tributor cap.
3. INSTALL HIGH-TENSION CORDS
(a) Install high-tension cords.
(b) Install the throttle body.
l Install the throttle body with the four bolts.
l Connect the PCV hose.
0 Connect the throttle cables or accelerator con
netting rod.
l Install the throttle body bracket.
0 Connect the air cleaner hose.

IGNITION SYSTEM - On-Vehicle Inspection (‘/M-GE)
IG-lf.
~. .
__
1
8 SST I ffio59
IGOt! i2
INSPECTION OF SPARK PLUGS
(Conventional Tipped Type Spark Plug)
1. REMOVE SPARK PLUGS
(a) Remove the high-tension cords.
(See page. IG-6)
2.
3.
I
lGOl48
4.
5. (b) Using SST, remove the spark plug.
SST 0915~5-16100
CLEAN SPARK PLUGS
Using a spark plug cleaner or wire brush, clean the spark
plug.
VISUALLY INSPECT SPARK PLUGS
Check the spark plug for electrode wear, threads damage
and insulator damage.
If abnormal, replace the plugs.
Recommended spark plugs:
ND Q20R- U
NGK BCPRGEY
ADJUST ELECTRODE GAP
Carefully bend the outer electrode to obtain the correct
electrode gap.
Correct electrode gap: 0.8 mm (0.031 in.)
INSTALL SPARK PLUGS
(a) Using SST, install and torque the spark plug.
SST 09155-l 6100
Torque : 180 kg-cm (13 ft-lb, 18 Nmrn)
I..

IO-8 IGNITION’SYSTEM - On-Vehicle Inspection (7M-GE)
(Platinum tipped Type Spark Plug)
CAUTION:
l Never use a wire brush for cleaning.
l Never attempt to adjust gap on used plug.
l Spark plugs should be replaced every 80,000 miles
(100,000 km).
Megger
IGOlr 17
1. INSPECT ELECTRODE
(a) If using a megger (insulation resistance meter):
0 Remove the high-tension cords. (See page G-6)
0 Measure the insulation resistance.
Correct insulation resistance: 10 MQ or more
If less than 10 MAI , proceed to step 2.
I . IG01481
IG059
0 Visually inspect the spark plugs.
If the electrode is dry ,.... Okay
If the electrode is wet ..,.. Proceed to step 3
2, REMOVE SPARK PLUGS
(a) Remove the high-tension cords. (See page IS-61
Ib) Using SST, remove the spark plug.
SST 09155-l 6100

IGNITION SYSTEM
- On-Vehicle Inspection (7M-GE)
,“lG-9
16031
0.8 mm (7M-GTE)
1 .I
mm (7M-GE)
VISUALLY INSPECT SPARK PLUGS
Check the spark plug for thread or insulator damage.
If abnormal, replace the plug.
Recommended spark plugs:
7M-GE’ ND
PQ16R ’
NGK BCPR5EPll
7M-GTE ND
PQ20R-P6
NGK BCPRGEP-N8
INSPECT ELECTRODE GAP
Maximum electrode gap:
7M-GE
1.3 mm (0.051 in.)
7M-GTE 1.0 mm (0.039 in.)
If the gap is greater than maximum, replace the plug.
Correct electrode gap of new plug:
7M-GE
1.1 mm (0.043 in.)
7M-GTE 0.8 mm (0.031 in.)
If adjusting the gap of a new plug, bend only the base of
5. CLEAN SPARK PLUGS
6. the ground electrode, do not touch the tip.
If the electrode has traces of wet carbon, allow it to dry
and then clean with a spark plug cleaner.
Air pressure: Below 6 kg/cm2 (85 psi, 588 kPa)
Duration : 20 seconds or less
NOTE: If there are traces of oil, remove it with gasoline
before using the spark plug cleaner.
INSTALL SPARK PLUGS
(a) Using SST, install and torque the spark plug.
SST 09155-l 6100
Torque : 180 kg-cm (13 ft-lb, 18 N*m)
(b) Install the high-tension cords.

16-10 IGNITION SYSTEM - On-Vehicle Inspection (‘IM-GE)
I MA
MS
n
MS
39
i4
-3
INSPECTION OF IGNITION COIL
1. DlSCOtiNECT HIGH-TENSION CORD
(See page IO-61
‘2. INSPECT PRIMARY COIL RESISTANCE
Using an ohmmeter, measure the resistance between the
positive (+I and negative (-1 terminals.
Primary coil resistance (cold): .,
MA 0.24 - 0.30 (n
MS 0.41 - 0.50 rzZ
If the resistance is not as specified, replace the ignition
coil.
3. INSPECT SECONDARY COIL RESISTANCE
Using an ohmmeter, measure the resistance between the
positive (+I terminal and high-tension terminal.
Secondary coil resistance (cold):
MA 9.2- 12.4kfi
MS 10.2 - 13.8 ka
If the resistance is not as specified, replace the ignition
coil.
4. RECONNECT HIGH-TENSION CORD
(See page IG-61
INSPECTION OF IGNITER
(See procedure IG-5)