fuel pressure TOYOTA CELICA 1987 Service Repair Manual

FI-1
i’.. ;
-EFI SYSTEM
i
‘x
. .
Page
SYSTEM DESCRIPTION
....................... Fl-i.&.
PRECAUTIONS
;;:“, F,-, ;a”“- .............................. . ....
INSPECTION PRECAUTIONS
FI-7 . ....................
TROUBLESHOOTING
.......................... FI-12
DIAGNOSIS SYSTEM
.................... .
.... FI-25
TROUBLESHOOTING WITH
VOLT/OHMMETER (MA)
.................... FI-34
m
.:
TROUBLESHOOTING WITH
VOLT/OHMMETER (MS)
.................... FI-57
FUEL SYSTEM
................................ FI-73,
Fuel Pump ..................................
FI-73
Cold Start Injector ...........................
Fl-80
Pressure Regulator
.......................... FI’i84 ..
Injectors
.............................. ..i ..
FI-86
AIR INDUCTION SYSTEM
..................... FI-96
Air Flow Meter (7M-GE)
..................... FI-96
Air Flow Meter (7M-GTE)
................... FI-98
Throttle Body
.............................. FI-102
Idle Speed Control (ISC) Valve
............... FI-108
ELECTRONIC CONTROL SYSTEM .............. FI-110
Location of Electronic Control Parts .......... FI-110
l EFI Main Relay
............................. Fl-112
. Circuit Opening Relay ....................... FI-113
Solenoid Resistor
........................... Fl-114
Cold Start Injector Time Switch ...............
FI-115
Water Temperature Sensor ..................
FI-116
Fuel Pump Relay and Resistor ............... FI-117
High Temperature Line Pressure -
Up System ............................... FIi119
High Altitude Compensation (HACK
System (7M-GTE)
........................ FI-121
Oxygen Sensor .............................
FI-122
Electronic Controlled Unit (ECU) .............
FI-125
Fuel Cut RPM
.............................. FI-128

1-6 EFI SYSTEM - System Description
‘he .EFI system is composed of 3 basic sub
;ystems; Fuel Induction, Air Induction and
Ziectronic Control.
FUEL SYSTEM
An electric fuel pump supplies sufficient fuel,
under a constant pressure, to the injectors. These
injectors inject a metered quantity of fuel into the
intake manifold in accordance with signals from
the ECU (Electronic Control Unit).
AIR INDUCTION SYSTEM
The air induction system provides sufficient air for
engine operation.
[3: ‘I
i&TRONIC CONTROL SYSTEM
The 7M-GE, 7M-GTE engines are equipped wifh a
Toyota Computer Control System (TCCS) which
centrally controls the EFI, ESA, Diagnosis systems,
etc. by means of an Electronic Control Unit (ECU -
for-merly EFI computer) employing a microcom-
puter.
By means of the ECU, the TCCS controls the
following functions:
1. Electronic Fuel injection (EFI)
The ECU receivers signals from,various sen-
sors indicating changing engine operating
conditions such as:
Exhaust oxygen content (w/ TWC)
Intake air volume
i Intake air temperature
Coolant temperature
Engine rpm
Vehicle speed
Acceleration/deceleration etc.
These signals are utilized by the ECU to
determine the injection duration necessary for
an optimum air-fuel ratio.
2. Electronic Spark Advance (ESA)
The ECU is programmed with data for
optimum ignition timing under any and all
operating conditions. Using data provided by
sensors which monitor various engine func-
tions (rpm, A/C signal, coolant temperature,
etc.), the microcomputer (ECU) triggers the
spark at precisely the right instant. (See IG
section) 3. Idle Speed Control (IX)
The ECU is programmed with, target idling
speed values to respond to different engine
conditions (coolant temperature, air condi-
tioner on/off, etc.). Sensors transmit signals
to the ECU which control the flow of air
through the bypass of the throttle valve and
adjust idle speed to the target value.
(See pages FI-53, 7 1, 108) ’
4. Diagnosis
The ECU detects any malfunctions or abnor-
malities in the sensor network and tights the
“CHECK ENGINE” warning light on the instru-
ment panel. At the same time, the trouble is
identified and a diagnostic code is recorded
by the ECU.
5. Fail-Safe Function ’
In the event of computer malfunction, a back-
up circuit will take over to provide minimal
drivability. Simultaneously, the “CHECK
ENGINE” warning light will come on.

FI-10 EFI SYSTEM - inspection Precautions
L Fco97 FlOO91
I
. FI159
i. 4 Gasket
New
‘Gasket
I / FM067 FHOE
Fulcrum Length
19
54
-.
(b) insert the tester probe into the connector from the
wiring side when-checking the continuity,,amperage
L
or voltage.
(c) Do not apply unnecessary force to the terminal.
(d) After checking, install the water-proofing rubber on
the connector securely.
10. Use SST for inspection or test of the injector, cold start
injector or its wiring connector.
SST 09842-30050 and 09842-30060
FUEL SYSTEM
1.
2. When disconnecting the high fuel pressure line, a large
amount of gasoline will spill out, so observe the following
procedure.
(a) Put a container under the connection.
(b) Slowly loosen the connection.
(c) Disconnect the connection.
(d) Plug the connection with a rubber plug.
When connecting the flare nut or union bolt on the high
pressure pipe union, observe the following procedure:
(Union bolt type)
(a) Always use a new gasket.
(b) Hand tighten the union bolt.
(c) Tighten the bolt to the specified torque.
Torque: 300 kg-cm (22 it-lb, 29 N*m)
(Flare nut type)
(a) Apply a thin coat of oil to the flare and tighten the
flare nut.
(b) Then using SST, tighten the nut to the specified tor-
que.
SST 09631-22020
Torque: 310 kg-cm (22 ft-lb, 30 N*m)
NOTE: Use a torque wrench with a fulcrum length of 30
cm (11.81 in.).

EFI SYSTEM
- inspection Precautions
FI-11
I CORRECT i
Gro
Q * Delivery
Ring pipe
*
Black Ring
Delivew
Pipe -
O-Ring
-Grommet
3.
4.
5. Observe the fo!lowing’ precautions when removing and
installing the injectors.
(a) Never reuse a O-ring.
(b) When placing an O-ring on the injector, use care care
not to damage it in any way.
(c) Lubricate the O-ring with spindle oil or gasoline
before installing - never use engine, gear or brake oil.
Install the injector to the delivery pipe and cylinder head as
shown in the figure.
‘NOTE: Install the spacer with the black ring side facing
upward.
Check that there are no fuel leaks after performing any
maintenance on the fuel system.
(a) With engine stopped, turn the ignition switch ON.
(b) Short circuit the fuel pump check terminal +B and FP
of the check connector with the service wire.
CHECK CONNECTOR LOCATION:
See pages FI-110, 111
(c) When the fuel return hose is pinched, the pressure
within the high pressure line will rise to about 4 kg/
cm (57 psi, 392 kPa). In this state, check to see that
there are no leaks from any part of the fuel system.
CAUTION: Always pinch the hose. Avoid bending as
it may cause the hose to crack.

EFI SYSTEM - Troubleshooting
FI-1 E
CONTINUED FROM PAGE FI-14 ._
CHECK FUEL SUPPLY TO INJECTOR
1. Fuel in tank
2. Fuel pressure in fuel line
(1) Short terminals +B and FP of the
check connector.
(2) You can feel fuel pressure in fuel
return hose. BAD 1. Fuel line - leakage - deformation
2. Fuse
3. Fuel pump (See age FI-73)
4. Fuel filter
5. Fuel pressure regulator (See. page FI-84)
6. Circuit opening relay (See page FI-1 13)
3. Check circuit opening relay
(See page FI-1 13)
OK
CHECK FUEL PUMP SWITCH IN AIR
FLOW METER (7M-GE)
Check continuity between terminals FP and
El with measuring plate of,air flow meter
,,’
open.
L
I BAD c
Air flow meter (See page FL96)
I OK
CHECK IGNITION TIMING
1. Short terminals T(MA) or TEl (MS) and
El of the check connector.
2. Check ignition timing.
STD: 10’ BTDC @ Idle
short circuited TIMA) or
3
I OK NO Adjust ignition timing (See page EM-l 7)
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

l-16 EFI SYSTEM - Troubleshooting
SYMPTOM - ENGINE OFTEN STALLS
CHECK DIAGNOSIS SYSTEM
Check for output of diagnostic code.
(See page Fl-26) * Diagnostic code(s) (See pages FI-30, 31, 32)
Malfunction
code(s)
Normal code
CHECK FOR VACUUM LEAKS IN AIR
INTAKE LINE BAD 1. Oil filler cap
2. Oil level gauge
3. Hose connections
4. PCV hose
I OK
CHECK FUEL SUPPLY TO INJECTOR
‘*-- Fuel in tank BAD
L. Fuel pressure in fuel line
(1) Short terminals +B and FP of the check
connector.
(2) You can feel fuel pressure in fuel
return hose. .
3. Check circuit opening relay
(See page FI-113) .
1. Fuel line - leakage - deformation
2. Fuse
3. Fuel.pump (See’ page FI-73)
4. Fuel filter
5. Fuel pressure regulator (See page FI-84)
6. Circuit opening relay (See page FI:1 13).
,
OK
CHECK AIR FILTER
I BAD Element - Clean or replace
OK
CHECK IDLE SPEED
STD: 7M-GE wl TWC 700 rpm
7M-GE w/o TWC 800 rpm
7M-GTE 800 rpm
t w
BAD ISC system
(I 1 Wiring connection
(21 ISC valve
(3) ECU
CHECK IGNITION TIMING ‘-
‘I. Short terminals TiMA) or TEl (MS) and
El of the check connector..
2. Check ignition timing.
STD: 10” BTDC @ Idling
short circuited T(MA) or
1
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 (0.031 in.)
NOTE: Check compression pressure and
-I------- :+ -nyrpCCpn, c
NO
-I-
BAD - Adjust ignition timing. (See page EM-1 7)
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.)

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.

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