TOYOTA CELICA 1987 Service Workshop Manual

EFI SYSTEM - Troubleshooting
OK ‘. .CONTINUED FROM PAGE FI-I 6
m
CHECK COLD START INJECTOR
1. Cold start injector
(See page FI-80) BAD
2. Cold start injector time switch
(See page FL11 5)
OK FI-17
CHECK FUEL PRESSURE
(See page FI-74) BAD p 1. Fuel pump (See page FL73)
2. Fuel filter
3. Fuel pressure regulator (See page FI-84)
OK
CHECK INJECTORS
(See page FI-86) c
-
BAD Injection condition
I OK
..I
’ CHECK EFI ELECTRONIC CIRCUIT
USING VOLT/OHMMETER
(See pages FI-34, 57) BAD 1. Wiring connection
2. Power to ECU
(I) Fusible links
(2) Fuses
(3) EFI main relay
3. Air flow meter
4. Water temp. sensor
5. Air temp. sensor
6. Injection signal circuit
(I 1 Injector wiring
SYMPTOM - ENGINE SOMETIMES STALLS
I
CHECK DIAGNOSIS SYSTEM
Check for output of diagnostic code.
‘I ,. ,dSee page FI-26)
I Normal code
I
CHECK AIR FLOW METER’
Air flow meter
(See pages .Fl-96, 98)
I
OK
CHECK WIRING CONNECTORS AND
RELAYS 1 BAD --
2’ EFI main relay (See page FI 112)
Check for a signal change when the connec- 3. Circuit opening relay (See page FI-113)
tor or relay is slightly tapped or wiggled.

a EFI SYSTEM - Troubleshooting
SYMPTOM - ROUGH IrIiLlNG AND/OR MISSING
iECK DIAGNOSIS SYSTEM
leek for output of diagnostic code.
ee page FI-26)
1 -c Diagnostic code(s) (See pages FI-30, 31, 32)
Malfunction
code(s)
Normal code
HECK FOR VACUUM LEAKS IN’AIR
d-FAKE LINE
I OK’
If* “K AIR FILTER
ELEMENT Element - Clean or replace
I
I 1, Oil filler cap
2. Oil level gauge
3. Hose connections
4. PCV hose
5. EGR system - EGR vaive stays open (EGR)
OK
CHECK IDLE SPEED
STD: 7M-GE w/ TWC 700 rpm
7M-GE w/o TWC 800 rpm
7M-GTE
800 rpm
OK
,
BAD SC system
(1) Wiring connection
(2) ISC valve
(3) ECU
CHECK IGNITION TIMING
1, Short terminals T(MA) or TEI (MS) and
El of the check connector.
2. Check ignition timing.
STD: IO” BTDC @ Idling
w/ short circuited T(MA)
I TEl(MS1 - El NO F Adjust ignition timing. (See page EM-l 7)
i OK
‘.
7
I
CHECK SPARK PLUGS
Plug gap:
7M-GE Converitional Tipped Type
0.8 mm (0.031 in.)
7M-GE Platinum Tipped Type
1.1 mm (0,043 in.)
7M-GTE
0.8 mm (0.031 in.)
NOTE: Check compression pressure and
valve clearance if necessary.
OK CONTINUED ON PAGE FI-19 BAD 1. Spark plugs
2. Compression pressure
Limit: 9.0 kg/cm2 (128 psi, 883
kPa)
at 250 rpm
3. Valve clearance (Cold)
STD: IN 0.15 - 0.25 mm
(0.08 - 0.010 in.)
EX 0.20 - 0.30 mm
(0.008 - 0.012 in.)

EFI SYSTEM - Troubleshooting
FI-19
CONTINUED FROM PAGE Fl-18 ._
t
CHECK COLD START INJECTOR *
(See page FI-80) BAD 1. Cold start injector
2. Cold start injector time switch
(See page FL11 5)
CHECK FUEL PRES$URE
(See page FL74) BAD c 1. Fuel pump (See page FI-73)
2. Fuel filter
.3. Fuel pressure regulator (See page FI-84)
I
I 1 c 4
/OK
I
CHECK INJECTORS
(See page FI-86) 8AD * Injection condition
I OK
L 1
ZHECK EFI ELECTRONIC CIRCUIT
USING VOLT/OHMMETER
(See pages FL34, 57) c
BAD 1. Wiring connection
2. Power to ECU
\‘l’, F;t;e links
(3) EFI main relay
3. Air flow meter
4. Water temp. sensor
5. Air temp. sensor
6. Throttle position sensor
7. Injection signal circuit
(1) injector wiring

.20 EFI SYSTEM - Troubleshooting __
SYMPTOM - HIGH ENGINE IDLE SPEED (NO DROP)
:HECK ACCELERA
OK
CHECK POWER STEERING !DLE+JP
SYSTEM
OK .
‘:
j..l.
CHECK DIAGNOSIS SYSTEM
Check for output of diagnostic code.
(See page FI-26) ‘:.
_T I Linkage - Stuck
I
9
BAD * Air valve
I
r
* Diagnostic code(s) (See pages FI-30, 31, 32)
Malfunction
..
code!s)
Normal code
.
CHECK ISC SYSTEM
BAD
I
OK
71
(Air con Throttle posrtron sensor - ECU)
1 CHECK THROTTLE POSITION SENSOR
t-x- Throttle body
OK
CHECK FUEL PRESSURE
(See page FI-74) 7
BAD w Fuel pressure regulator - High pressure
OK
CHECK COLD START INJECTOR
~ .ee page FI-80) BAD w Cold start injector - Leakage
CHECK INJECTORS (See page FI-86)
I Injectors - Leakage, Injection quality
I OK
CHECK EFI ELECTRONIC CIRCUIT USING
VOLT/OHMMETER
(See pages FI-34, 57) BAD - 1. Wiring connection
2. Power to ECU
(1) Fusible links
(2) Fuses
(3) EFI main relay
3. Air flow meter
4. Water temp. sensor
5. Air temp. sensor
6. Injection signal circuit
(1) Injector wiring
(2) Resistor
(3) ECU

EFI SYSTEM - Troubleshooting
FI-21
-.
SYMPTOM - ENGINE BACKFtRES-Lean Fuel Mixture
CHECK DIAGNOSIS SYSTEM
Check for output of diagnostic code
(See page FI-26) Malfunction --) Diagnostic code(s) (See pages FI-30, 31, 32)
.code 1s) j
,
Normal code
CHECK FOR VACUUM LEAKS IN AIR
INTAKE LINE
1. Short terminals T(MA) or TEl (MS) and BAD -
NO 1. Oil filler cap
2. Oil dipstick
3. Hose connections
4. PCV hose
Adjust ignition timing. (See page EM-1 7)
1. Cold start injector
2. Cold start injector time switch
(See page FI-115)
CHECK FUEL PRESSURE
(See page FI-74)
I
I
BAD 1. Fuel pump (See page‘ FI-73)
2. Fuel filter
3. Fuel pressure regulator (See page Fl-84)
I
’ “,HECK INJib
‘I- See page FI-86)’ - Injectors - Clogged
BAD
. ., .l
I OK
CHECK Eii ELECTRONIC ClR&lT
USING VOLT/OHMMETER
(See pages FI-34, 57)
4
BAD 1. Wiring connection
2. Power to ECU
(1) Fusible links
(2) Fuses
(3) EFI main relay
3. Air flow meter
4. Water temp. sensor
5. Air temp. sensor
6. Throttle position sensor
7. Injection signal circuit
(1) Injector wiring
Ii, zesstor
(4) Fuel cut signal
8. Oxygen sensor

Ii-22 EFI SYSiiM - Troubleshooting
SYMPTOM - MUFFLER EXPLOSION (AFTER FIRE)
-Rich Fuel Mixture-Misfire
CHECK DIAGNOSIS SYSTEM
Check for output of diagnostic code
(See page FI-26) pm Diagnostic code(s) (See pages Fl-30, 31, 32)
Malfunction
code(s)
4
c
Normal code
CHECK IGNITION TIMING
1. Short terminals TiMA) or TEl (MS) and
El of the check connector.
2. Check ignition timing.
STD: IO” BTDC @ Idling
w/ short circuited TfMA) or
C TEl(MS) - El I
OK NO
BAD
I-
Adjust ignition timing. (See page EM- 17)
I
1. Cold start injector
2. Cold start injector time switch
(See page FI- 115)
1
CHECK INJECTORS
BAD injector - Leakage
I
I OK
CHECK SPARK PLUGS
Plug gap:
7M-GE Conventional .Tipped Type
0.8 mm (0.031 in.)
7M-GE Platinum Tipped Type
1.1 mm (0.043 in.)
7M-GTE
0.8 mm (OiO31 in.)
NOTE: Check compression pressure and
valve clearance if necessary.
OK
CHECK EFI ELECTRONIC CIRCUIT USING
VOLT/OHMMETER
(See pages Fl-34, 57) NO
BAD - 1. Spark plugs
2. Compression pressure
Limit: 9.0 kg/cm2 (128 psi, 883
kPa)
at 250 rpm
3. Valve clearance (Cold)
STD: IN 0.15 - 0.25 mm
(0.06 - 0.010 in.)
EX 0.20 - 0.30 mm
(0.006 - 0.012 in.)
i
1. Throttle position sensor
2. Injection signal circuit
(I) Injector wiring
(2) Resistor
(3) ECU
3. Oxygen sensor

EFI SYSTEM - Troubleshooting
FI-23
SYMPTOM - ENGINE HESITATES AND/OR POOR ACCELERATION
CHECK CLUTCH AND BRAKE .
BAD
I
I 1
1 OK
CHECK FOR VACUUM LEAKS IN AIR
INTAKE LINE
I OK BAD
I-
1. Clutch - Slips
2. Brakes - Drag
1. Oil filler cap
2. Oil level gauge
3. Hose connections :
4. PCV hose
5. EGR system - EGR valve stays open (EGR)
4
CHECK AIR FILTER ELEMENT
BAD Element - Clean or replace
I
,,: -. OK
7
. . 1 i , 1
CHECK DIAGNOSIS SYSTEM
Check for output of diagnostic code.
(See page FI-26) Malfunction
I-- code Diagnostic code(s) (See pages FI-30, 31, 32)
I
I I I J
1 Normal code
CHECK IGNITION SPARK
7M-GE (See page IO-61
7M-GTE (See page 16-12) .
BAD
I
I OK
CHECK IGNITION TIMING
1. Short terminals T(MA1 or TEl (MS) and
El of the check connector.
2. Check ignition timing.
‘i, STD: 10” BTDC @ Idling
I short circuited TiMA) or
I
I OK
CHECK FUEL PRESSURE
(See page Fl-74) 1. High-tension cords
2. Distributor (7M-GE) or cam position
sensor (7M-GTE)
3. Ignition coil
4. Igniter
NO Adjust. ignition timing. (See page EM- 17)
I
I
BAD
I
1. Fuel pump (See page Fl-73)
2. Fuel Filter
3. Fuel pressure regulator (See page Fl-84)
1
OK
CHECK INJECTORS
(See page FI-86) BAD c Injection condition
OK CONTINUED ON PAGE FI-24

. .
FI-24 EFI SYSTEM - Troubleshooting
,)
OK CONTINUED FROM PAGE FL23
1
CHECK SPARK PLUGS
Plug gap:
7M-GE Conventional Tipped Type
03 mm (0.031 ,in.) .~
7M-GE Platinum Tipped Type
1.1 mm (0.043 in.)
7M-GTE
0.8 mm (0.031 in.)
NOTE: Check compression prossure and
valve clearance if necessary.
.
. r L
BAD
1
;HECK EFI ELECTRONIC’CIRCUIT
-;-;ilNG VOLT/OHMMETER
_
(See-pages FI-34;‘57) Y
.
1. Spark plugs
2. Compression pressure
Limit: 9.0 kg/cm2 (128 psi, 883
kPa)
at 250 rpm
3. Valve clearance (Cold)
STD: IN 0.15 - 0.25 m&
(0.06 -‘.O.OlO in.)
EX 0.20 - 0.30 mti
(0.008 - 0.012 in.1
c
BAD 1. Wiring connection
2. Power to ECU
(I) Fusible links
(2) Fuses
(3) EFI main relay
3. Air flow meter.
4. Water temp. sensor
5. Air temp. sensor
6. Throttle position sensor
7. Injection signal circuit
(I) Injector wiring
(2) Resistor
(3) ECU ’

EFI SYSTEM - Diagnosis System
. .
DIAGNOSIS SYSTEM
__ --
FL25
(MA)
The ECU contains a built-in self-diagnosis system by which
troubles with the engine signal network are detected and a
“CHECK ENGINE” warning light on the instrument panel
flashes,
By analyzing various signals as shown in the later table (See
pages Fl-30, 31) the Electronic Control Unit (ECU) detects
system malfunctions which are related to the various operating
parameter sensors or to the actuator. The ECU stores the
failure until the diagnosis system is cleared by removing the EFI
fuse with the ignition switch off.
A “CHECK ENGINE” warning light on the instrument panel
informs the driver that a malfunction has been detected.
The light goes out automatically when the malfunction has
been cleared.
The diagnostic code can be read by the number of the blinks of
the “CHECK ENGINE” warning light when T and El are short-
circuit.
(MS)
The ECU contains a built-in self-diagnosis system by which
troubles with the engine signal network are detected and a
“CHECK ENGINE” warning light on the instrument panel
flashes.
By analyzing various signals as shown in the later table (See
page FI-32) the Electronic Control Unit (ECU) detects system
malfunctions which are related to the various operating
parameter sensors or to the actuator. The ECU stores the
failure until the diagnosis system is cleared by removing the EFI
fuse with the ignition switch off.
In the ECU, a test mode function has been added to the func-
tions of the self-diagnosis system of the previous diagnosis
mode (normal mode) for the purpose of detecting malfunctions
such as poor contact which are difficult to detect in the normal
mode. This function fills up the self-diagnosis system. The test
mode can be implemented by the technician to follow the pro-
cedures of appropriate check terminal connection and opera-
tion described in later (See page FI-28).
In the normal mode, the self-diagnosis system monitors 14
items, indicated by the codes except for code No. 51 as shown
in FI-32. A “CHECK ENGINE” warning light on the instrument
panel informs the driver that a malfunction has been detected.
The light goes out automatically when the malfunction has
been cleared.
The diagnostic code can be read by the number of the blinks of
the “CHECK ENGINE” warning light when TEl and El are
short-circuited.

FI-26 EFI SYSTEM - Diagnosis System
-.
i
“CHECK ENGINE” Warning Light In the test mode, seven items, indicated by code
24, 41, 42, 43, and 5 1, as shown in FI-32 are m
malfunction is detected in any one of the systems
code Nos. 13, 22, 24, and 41 the ECU lights the “CHECK
ENGINE” warning light to warm the technician that the mal-
function has been detected. In this case, TE2 and El terminals
on the check connector should be connected as shown later
(See page FI-28)
In the test mode, for all seven conditions shown above in code
Nos. 13 - 51, even if the malfunction is corrected, the mal-
function is stored in the ECU memory while the ignition switch
remains on. Also, when a malfunction occurs for-the four con-
ditions from code Nos. 13 - 41, the “CHECK ENGINE” warning
light remains on. However, once the ignition switch is turned to
OFF, the ECU erases all of the malfunctions in the memory. The
diagnostic mode (normal or test) and the output of the “CHECK
ENGINE” warning light can be selected by the TEl , TE2 and El
terminal connections on the check connector, as shown in the
later.
“CHECK ENGINE” WARNING LIGHT CHECK
1. The “CHECK ENGINE” warning light will come on when
the ignitiorqw:@ch is placed at ON and the engine is not
running. -y.
2. When the engine is started, the “CHECK ENGINE” warning
light should go out.
If the light remains on, the diagnosis system has detected
a malfunction or abnormality in the system.
OUTPUT OF DIAGNOSIS CODES
(MA)
To obtain an output of diagnostic codes, proceed as follows:
1. Initial conditions ,’
(a)’ Battery voltage about 11 volts
(b) Throttle valve fully closed (throttle position sensor
IDL points closed)
(cl Transmission in neutral position
(d) Accessory switches OFF
2. Turn the ignition switch to ON. Do not start the engine.