low oil pressure TOYOTA CELICA 1987 Service Repair Manual

. COOLING SYSTEM - Description
co;3
RESERVOIR TANK
The reservoir tank is used to catch coolant
which overflows the cooling systein as a result of
volumetric expansion when the coolant is heated.
The coolant in the reservoir tank returns to the
radiator when the coolant temperature drops, thus
keeping the radiator full at all times and avoiding
needless coolant loss. Check the reservoir tank
level to learn if the coolant needs to be rep-
lenished.
WATER PUMP
The water pump is used for forced circulation of
coolant through the cooling system. It is mounted
on the front of the cylinder block and driven by a
V-ribbed belt,
THERMOSTAT I The cooling system is composed of the water
jacket (inside the cylinder block and cylinder head),
radiator, water pump, thermostat, cooling fan,
hoses and other components.
Coolant which is heated in the water
jacket is
pumped to the radiator, through which a cooling
fan blows air to cool the coolant as it passes
through. Coolant which has been cooled is then
sent back to the engine by the water pump, where
it cools the engine.
The water jacket is a network of channels in the
shell of the cylinder block and cylinder head
through which coolant passes. It is designed to
provide adequate cooling of the cylinders are com-
bustion chambers which become the hottest dur-
ing engine operation.
F(/ “ IATOR
The radiator performs the function of cooling
the coolant which has passed through the water
jacket and become hot, and is mounted in the front
of the vehicle. The radiator consists of an upper
tank and ‘lower tank, and a core which connects
the two tanks. The upper tank contains the inlet for
coolant from the water jacket and the filter inlet. It
also has a hose attached through which excess
coolant or steam can flow. The lower tank contains
the outlet for coolant and the drain cock. The core
contains many tubes through which coolant flows
from the upper tank to the lower tank as well as
cooling fins which radiate heat away from the coo-
lant in the tubes. The air sucked through the radia-
tor by cooling fan, as well as the wind generated
by the vehicle’s travel, passes through the radia-
tor, cooling it. Models with automatic transmission
incrl*-le an automatic transmission fluid cooler built
in:.
.le lower tank of the radiator.
RADIATOR CAP
The radiator cap is a pressure type can which
seals the radiator, resulting in pressurization of the
radiator as the coolant expands. The pressuriza-
tion prevents the coolant from boiling even when
the coolant temperature exceeds 100°C. A relief
valve (pressurization valve) and a vacuum valve
(negative pressure valve) are built into the radiator
zap. The relief valve opens and lets steam escape
:hrough the overflow pipe when the pressure
3enerated inside the cooling system exceeds the
imit (coolant temperature:
110 - 1 20°C, (230
- 248”F), pressure; 0.3 - 1 .O kg/cmz, (4.3 - 14.2
)si, 29.4 - 98.1 kPa). The vacuum valve opens to
3ljeviate the vacuum which develops in the coolant
system after the engine is stopped and the coolant
emperature drops. The valve’s opening allows the
)ressure in the cooling system to return to the
Qclant in the reservoir tank. The thermostat has a wax type and is mounted
in the. water outlet housing. The thermostat
includes a type of automatic valve operated by
fluctuations in the coolant temperature. This valve
closes when the coolant temperature drops, pre-
venting the circulation of coolant through the
engine and thus permitting the engine to warm up
rapidly. The valve opens when the coolant tem-
perature has risen, allowing the circulation of coo-
lant. Wax inside the thermostat expands when
heated and contracts when cooled. Heating the
wax thus generates pressure which overpowers
the force of the spring which keeps the valve
closed, thus opening the valve. When the wax
cools, its contraction causes the force of the
spring to take effect once more, closing the valve.
The thermostat in this engine operates at a tem-
perature of 88”C(19O”F).
I
I

co-14
-.
COOLINQ SYSTEM. - Radiator
Tank Plate
O-Ring 6. 0 Do not stake the areas protruding around the pipes,
brackets or tank ribs.
l The points shown in the illustration cannot be staked
with the SST. Use a pliers and be careful not to damage
the core plate.
INSPECT FOR WATER LEAKS
(a) Tighten the drain plug.
(b) Plug the oil cooler pipes to prevent any water leakage
into the oil cooler.
(c) Plug the inlet and outlet pipes of the radiator with
SST.
SST 09230-00010
(d) Using a radiator cap tester, apply pressure to the
radiator.
Test pressure: 1.5 kg/cm2 (21 psi, 147 kPa)
(e) Inspect for water leaks.
NOTE: On radiator with resin tanks, there is a clearance
between the core plate and tank plate where a minute
amount of air will remain, giving the apperance of an air
leak when the radiator is submerged in water.
Therefore, before performing the water leak test, first
swish the radiator around in the water until all air bubbles
disappear.
7. PAINT TANK PLATES
NOTE: If the water leak test checks out okay, allow the
radiator to completely dry and then paint the tank plates.

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-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

I-30 .EFl SYSTE.M - Diagnosis System
DIAGNOSTIC CODES (MA)
Trouble area
I See
page Code Number of
; No. Che;;;;gine System
I
- nnrulno4 Norma’ Diagnosis
This appears when none of
the other codes area identified.
0
Ignition switch circuit
Ignition switch T
Main relay circuit
1 Main relay
1 ECU FI-41
1 Distributor circuit
r Distributor
) Starter signal circuit
b ECU
) Distributor circuit
B Distributor
B ECU IG-3
IG-3 ECU (+B) fl n Momentary interruption in 0
11
power supply to ECU.
I 0
l
Jo “NE” or “G” signal to
ICU within 2 seconds after
engine has been cranked.
Uo “NE” signal to ECU when
sngine Sp88d is above
1,000 rpm.
No “IGF” signal to ECU
i- 8 times in succession.
Ietectinn of oxygen sensor
jeterioration. E
t
C
i
P. Open or short circuit in wate
temp. sensor signal.
Open or short circuit in intake
air temp. sensor signal.
I7M-GE)
Air-flow
Meter Signal Open circuit in VC signal or
short circuit between VS and
E2 when idle contacts are
c tosed.
(7M-GTE)
Open or Short circuit in air
flow meter signal.
(‘IM-GE)
Open circuit in E2 or short
circuit between VC and VS.
(‘IM-GTE)
Open or short circuit in HAC
sensor signal
Turbocharger
Pressure ‘3
Turbocharger pressure is
abnormal. B Ignition and ignition coil
circuit
8 Igniter and ignition coil
0 ECU !I-5 1
gnition Signal
l-l 2
FI-4’
Fl-48
I!
(
!
1
,-
1
Fll608
nn n
FIl609
FI-44
d )r FI-4‘
FI-51
Open or short circuit in circuit
I Sensor Signal throttle position sensor signal. 0 Throttle position sensor
0 ECU
SHl,d , FI-4 0 Oxygen sensor circuit
l Oxygen sensor
0 ECU
0 Water temp. sensor
@muit
‘8 Water temp. sensor
l ECU
0 Intake air temp. sensor
circuit
8 Intake air temp. sensor
. ECU 3xygen Sensor
signal
Water Temp.
Sensor Signal Fll81t
Intake Air Tern
Sensor Signal 24
Fll81
0 Air flow meter circuit
0 Air flow meter
0 ECU
Fl161 0 Air flow meter Circuit
0 Air flow meter
0 ECU
0 HAC sensor circuit
l HAC sensor
l ECU
0 Turbocharger
8 Air flow meter
0 Intercooler system
0 ECU (‘IM-GE)
Air Flow
Meter Signal
(7M-GTE)
HAC Sensor
Signal Fl18
i-
,
0 Throttle position s8nsC I FIZE
n

FI-36 EFI SYSTEM - Troubleshooting with VoltjOhmmeter (MA)
Terminals of ECU. (7M;GTE)
Symbol Terminal Name Symbol Terminal Name Symbol Terminal Name
EOI POWER GROUND G2 CAM POSITION SENSOR A/C A/C MAGNETIC SWITCH
E02 POWER GROUND VTA
THROTTLE POSITION SENSOR SPD SPEEDOMETER
No, 10 INJECTOR (No. 1 and 4)
NE CAM POSITION SENSOR W
WARNING LIGHT
No. 20 INJECTOR (No. 2 and 6) IDL
THROTTLE POSITION SENSOR FPR FUEL PUMP RELAY
STA STARTER SWITCH IGT IGNITER OIL OIL PRESSURE SWITCH
No. 30 INJECTOR (No. 3 and 5) IGdA IGNITER THA AIR TEMP. SENSOR
STJ COLD START INJECTOR
IGF IGNITER ECT ECT COMPUTER
rEl COMPUTER GROUND KNKl KNOCK SENSOR
t HAC 1 tl
NSW
NEUTRAL START SWITCH (A/T) THW WATER TEMP. S
N/C ‘CLUTCH SWITCH (M/T) KNK2 KNOCK SENSOR 1 vc ) THROTTLE
AIR
FLOW I
LTITUDE COMPENSATION
, .xNSOR
ENSOR 1 FC 1 CIRCUITOPENING RELAY I
IGdB IGNITER ox OXYGEN SENSOR KS AIR FLOW METER
ISC 1 ISC MOTOR NO. 1 COIL E2 SENSOR GROUND BATT BATTERY
r
ISC 3 ISC MOTOR NO. 3 COIL
vsv VSV (FPU) +B EFI MAIN RELAY
ISC 2 ISC MOTOR NO. 2 COIL Ll ECT COMPUTER IG S/W IGNITION SWITCH
ISC 4 ISC MOTOR NO. 4 COIL HT OXYGEN SENSOR +Bl EFI MAIN RELAY
GO CAM POSITION SENSOR L2 ECT COMPUTER TIL
TURBO INDICATOR
VF CHECK CONNECTOR M-REL
EFI MAIN RELAY (COIL) DFG DEFOGGER RELAY
Gl CAM POSITION SENSOR L3 ECT COMPUTER LP HEADLIGHT RELAY
T CHECK CONNECTOR
EGR VSV (EGR)
ECU Terminals
E2 Ll L2 L3 A/C W OIL ECT FC KS +B +Bl
+
F10574 Fll 99:
*For cruise control

jS EFI SYSTEM - Troubleshooting with Volt/Ohmmeter (MS)
-.
0
“B”
Fl294.
ECU
EFI SYSTEM CHECK PROCEDURE
._
PREPARATION
(a) Disconnect the connectors from the ECU.
(b) Remove the locks as shown in the illustration so that
the tester probe(s) can easily come in.
CAUTION: Pay attention to sections “A” and “B” in
the illustration which can be easily broken,
(c) Reconnect the connectors to the ECU.
’
NOTE:
0 Perform ail voltage measurements with the connectors
connected.
0 Verify that the battery voltage is 1 IV or above when
the ignition switch is at “ON”.
Using a voltmeter with high-impedance (10 kQ/V mihimum),
measure the voltage at each terminal of the wiring con-
nectors.
Terminals of ECU
rmbol Terminal Name Symbol Terminal Name
Symbol Terminal Name
EOI POWER GROUND NE DISTRIBUTOR ACPS A/C PRESSURE SWITCH
co2 POWER GROUND El COMPUTER GROUND SPD SPEEDOMETER
o. 10 INJECTOR (No. 1 and 4) VF CHECK CONNECTOR ECT ECT COMPUTER
o. 30 INJECTOR (No. 3 and 5)
GO DISTRIBUTOR ACR A/C COMPRESSOR
o. 20 INJECTOR (No. 2 and 6) TE2 CHECK CONNECTOR Ll
ECT COMPUTER
ELS DEFOGGER SWITCH
HEADLIGHT SWITCH TEl CHECK CONNECTOR L2
ECT COMPUTER
FPU VSV (FPU) KNK KNOCK SENSOR FPR FUEL PUMP RELAY
ACV VSV (A/R CONTROL) THW WATER TEMP. SENSOR L3 ECT COMPUTER
SC 1 ISC MOTOR NO. 1 COIL IDL
THROTTLE POSITION SENSOR W
WARNING LIGHT
IGT IGNITER THA AIR TEMP. SENSQR
M-REL EFI MAIN RELAY (COIL)
SC- ISC MOTOR NO. 2 COIL VTA THROlTLE POSITION SENSOR IG SiW IGNITION SWITCH 3
ISC3 ISC MOTOR NO. 3 COIL vs AIR FLOW METER Bl EFI MAIN RELAY
ISC4 ISC MOTOR NO. 4 COIL vcc AIR FLOW METER
THROTTLE POSITION SENSOR BATT BATTERY
IGF IGNITER E2
SENSOR GROUND B
EFI MAIN RELAY
G2 1 DISTRIBUTOR 1 STA 1 STARTER SWITCH
Gl 1 DISTRIBUTOR 1 NSW 1 NEUTRALSTARTSWITCH
ZU Terminals

EM-26 ENGINE MECHANICAL - Compression Check
d
COMPRESSION CHECK
NOTE: If there is lack of power, excessive oil consump-
tion or poor fuel mileage, measure the cylinder compres-
sion pressure.
(7M-GE)
1.
2.
3.
4.
5.
6. REMOVE SPARK PLUGS (See page IO-71
7.
EM3003
WARM UP ENGINE
DISCONNECT COLD START INJECTOR CONNECTOR
DISCONNECT SOLEtiOlD RESISTOR CONNECTOR
DISCONNECT DISTRIBUTOR CONNECTOR
REMOVE THROTTLE BODY
(a) Remove the PCV hose.
(b) Disconnect the water by-pass hoses and plug the
hose end.
(c) Disconnect following hoses:
. fwl EGR)
VSV hoses
. (wl TWC)
BVSV hoses
. (w/ EGR)
EGR vacuum modulator hoses
l No.7 air hose
id) Disconnect the throttle position sensor connector.
(e) Remove the throttle body bracket(s).
(f) Remove the four bolts, throttle body and gasket.
CHECK CYLINDER COMPRESSION PRESSURE
(a) Insert a compression gauge into the spark plug hole.
(b) While cranking the engine with the starter motor,
measure the compression pressure.
NOTE: Always use a
fully charged battery to obtain an
engine revolution of more than 250 rpm.
(c) Repeat steps Ia) through Ib) for each cylinder.
Compression pressure:
11.0 kg/cm2 (156 psi, 1,079 kPa) or more
Minimum pressure:
9.0 kg/cm2 (128 psi, 883 kPa)
Difference between each cylinder:
1 .O kg/cm2 (14 psi, 98 kPa) or less
(d) If cylinder compression in one or more cylinders is
low, pour a smali amount of engine oil into the
cylinder through the spark plug hole and repeat steps
(a) through (b) for the cylinder with low compression.
0 If adding oil helps the compression, chances are
that the piston rings and/or cylinder bore are worn
or damaged.
0 If pressure stays low, a valve may be sticking or
seating improperly, or there may be leakage past
the gasket.

.
ENGINE MECHANICAL - Cylinder Head
-. 6. REMOVE ENGINE WIRE
(a) Disconnect following wires:
. fw/ TWC)
Oxygen sensor connector
l Oil pressure sender gauge connector
l Water temp. sensor connector
l Water temp. sender gauge connector
_-
l Cold start injector time switch connector
l Distributor connector
.,
l Injector connectors
l Three VSV connectors
l Knock sensor connectors
l Ground strap from intake manifold
(b) Remove the engine wire from the each clamps.
7.
REMOVE PULSATION DAMPER, VSV AND NO.1 FUEL
PIPE
6.
REMOVE NO.2 FUEL PIPE
(a) Disconnect the fuel hose from the No.2 fuel pipe.
(b) Remove the bolt,’ union bolt, No.2 fuel pipe and
gaskets.
9. (7M-GTE)
REMOVE AUXILIARY AIR PIPE
10. (7M-GE)
REMOVE HIGH-TENSION CORDS AND DISTRIBUTOR
11. (7M-GE)
REMOVE OIL DIPSTICK
12. (7M-GTE)
REMOVE TURBOCHARGER
(See steps 5 to 7 and 9 to 15 on pages TC-IO-to 12):