1987 TOYOTA CELICA Service Repair Manual

EFI SYSTEM - Electronic Control. System
FL127
ECU Wiring . .
3.
INSPECT RESISTANCE OF ECU
CAUTION: .-
l Do not touch the ECU terminals.
0 The tester probe should be inserted into the wiring
connector from the wiring side.
Check the resistance between each terminal of the wiring
connectors.
l Disconnect the wiring connectors from the ECU.
0 Measure th.e resistance each terminal.
I
Resistance of ECU Wiring Connectors
Terminals Condition
. I Resistance Ifi)
I
IDL : E2
VTA - E2
VC WCC) - E2 Throttle valve open
Throttle valve fully closed
Throttle valve fully open
Throttle valve fully closed cc
Less than 2,300
3,500 - 10,300
300 - 6,300
200 - 400
*‘VS - E2 Measuring plate fully closed
Measuring plate fully open 20 - 600
20 - 1,200
I *2KS -E2 co I I I
“2E2 +KS -
5,000 - 10,000 I
I
“2VC -E2
10,000 - 15,000
I “2E2 -+VC
I I 5,000 - 10,000 I
THA - E2
THW - E2
Gl,G2 - GO
NE-GO Intake air temperature 20°C (68’FI
. Coolant temperature 80°C (176°F) 2,000 - 3,000
200 - 400
140 - 180
Iscl, I%2 _ +a (8)
ISC3, ISC4 10-30
+2 HAC - E2 2,900 - 4,200
*I 7M-GE only
*2 7M-GTE only

Fl-128 EFI SYSTEM - Electronic Contpl SyStem
c
’ FlO54
Tachometer Fl114:
Fuel Cut RPM--
;INSPECTION OF FUEL CUT RPM
I.
2. WARM UP ENGINE
Allow the engine to reach normal operating temperature.
INSPECT FUEL CUT RPM
(a) Disconnect the connector from the throttle position
sensor.
(b) Short circuit terminals IDL and El on the wire con-
nector side.
(c) Gradually raise the engine rpm and check that there
is fluctuation the fuel cut and fuel return points.
NOTE: The vehicle should be stopped.
Fuel cut rpm:
1,800 rpm
Fuel return rpm: 1,200 rpm

-.
EM-1
I
ENGINE MECHANICAL .’ ../_ :.
F&e.
DESCRIPTION
. . . ..1........111.......~....~.~ E+ -;.’
TROUBLESHOOTING
. . . . . . . . . . . . . . . . n . ma m I. I.
EM-4’ ”
ENGINE TUNE-UP
. . . . . . . . . . . . ..~......~.......
COMPRESSION CHECK
s e . . . . . . . . . . . . . , . . . . . . .
TIMING BELT
,,,..,....................*.*...
EM-28
CYLINDER HEAD
. . . . . . . . . . . . . . ..*............
EM-37
CYLINDER BLOCK
1”1......1...............,..
EM-66

EM-2
ENGINE MECHANICAL - Description
-.
DESCRl.PTlON _
.-. ..‘. /,.
: --
+..>r:*. ,, .,. 2 ,-,. j . .:..,. .-
The 7M-GE and 7M-GTE engines are an in-line 6-cylinder 3.0 titer DOHC 24 valve engine. i
‘M:G.E. (MA)
..
: _
7M-GE (MS)
7M-GTE

ENGINE MECHANICAL -, Description
EM-3
The 7M-GE, 7M-GTE engines are an in-line 6-
cylinder engine with the cylinders numbered l-2-
3-4-5-6 from the front. The crankshaft is sup-
ported by 7 bearings specified by the inside of the
crankcase. These bearings are made of kelmet.
.The crankshaft is integrated with 8 weights
which are cast along with it for balancing. Oil holes
‘are built into the crankshaft for supplying oil to the
connecting rods, pistons and other components.
These engine’s ignition order is l-5-3-6-2-4 .
The cylinder head is made of aluminum alloy, with
a cross flow type intake and exhaust layout and
with pent roof type combustion chambers. The
spark plugs are located in the center of the com-
bustion chambers.
Exhaust and intake valves are equipped with
irregular pitch springs with symmetrical ends
made of oil tempered silicon chrome steel wire
which are capable of following the valves even at
,high engine speeds.
Both the exhaust side cam shaft and the. intake
side cam shaft are driven by a single timing belt.
The cam journal is supported at 7 places between
the valve lifters of each cylinder and on the
cylinder head of front end. Lubrication of the cam
journal and cam is accomplished by oil being sup-
plied through the oiler port in the center of the
camshaft.
Adjustment of the valve clearance is done by
means of an outer shim type system, in which
valve adjusting shims are located above the valve
lifters. This permits replacement of the shims
without removal of the camshafts.
The resin timing belt cover is made in 2 pieces.
Pistons are made of highly temperature-resis-
tant aluminum alloy, and depressions are built into
the piston head to prevent interference with
valves.
Piston pins are the full-floating type, with the
pins fastened to neither the piston boss nor the
connecting rods. Instead, snap rings are fitted on
both ends of the pins, preventing the pins from
falling out.
The No. 1 compression ring is made of stainless
steel and the No. 2 compression ring is made of
cast iron. The oil ring is made of a combination of
stainless steel. The outer diameter of each piston
ring is slightly larger than the diameter of the
piston
and the flexibility of the rings allows them
to hug the cylinder walls when they are mounted
on the piston. Compression rings No. 1 and No. 2
work to prevent the leakage of gas from the
cylinder and the oil ring works to scrape oil off the
cylinder walls to prevent it from entering the com-
bustion chamber.
The cylinder block is made of cast iron. It has 6
cylinders which are approximately 1.6 times the
length of the piston stroke. The top of the cylin- ders is closed off by the cylinder head and the
lower end of the cylinders becomes the crankcase,
in which the crankshaft is installed. In addition,- the
cylinder block contains a water jacket, through
which coolant is pumped to cool the cylinders.
The .oil pan is bolted onto the botiom of the
cylinder block. The oil pan is an oil reservoir made .
of pressed steel sheet. A dividing plate’is included
-inside the oil pan to keep sufficient oil in the bot-
tom of the pan even when the vehicle is tilted. This
dividing plate also prevent5 the oil from making
waves when the vehicle is stopped suddenly and
thus shifting the oil away from the oil pump suc-
tion pipe.

LM-4
I ENGINE MECHANICAL -* Troubleshooting
_.
TROUBLESHOOTING
Problem Possible cause I Remedy Page
Engine overheats Cooling system faulty Troubleshoot cooling system co-4
Incorrect ignition timing Reset timing EM-1 7
Engine will not crank or Starting system faulty Troubleshoot starting system ST-2
cranks slowly : .
Engine will not start/ Vacuum leaks Repair as necessary
hard to start 0 PCV hoses ”
(cranks OK) 0 (w/ EGR)
EGR valve
0 Intake manifold
0 Air intake chamber
0 Throttle body
0 ISC valve
Pulling in air between air flow meter and Repair as necessary FI-96, 93
throttle body
Ignition problems Perform spark test IG-5, 12
0 Ignition coil
0 Igniter
0 (7M-GE)
Distributor
(7M-GTE)
Cam position sensor
High-tension cord disconnected or broken Inspect cord IG-6, 13
No fuel supply to injector Troubleshoot EFI system FI-I 2
l No fuel in tank
0 Fuel pump not working
l Fuel filter clogged
0 Fuel line clogged or leaking
EFI system problems Repair as necessary
ISC system problem Check ISC system FL- 108
Spark plugs faulty Inspect plugs IG-7
Low compression Check compression EM-26, 2
Rough idle, stalls or Vacuum leaks Repair as necessary
misses 0 PCV hoses
0 (w/ EGR)
EGR valve
0 Intake manifold
0 Air intake chamber
0 Throttle body I
0 ISC valve
Pulling in air between sir flow meter and FI-96, 9
throttle body
Incorrect idle speed Check ISC system FI- 108
Incorrect ignition timing Reset timing EM-1 7
Ignition problems Perform spark test IG-5, 12
0 Ignition coil
0 Igniter
0 (-/M-GE)
Distributor
(-/M-GTE)
Cam position sensor
High-tension cord faulty Inspect cord IG-6, 13
EFI system problems Repair as necessary

ENGtNE MECHANKAL - Troubleshootinn EM-S
TROUBLESHOOTING (Cont’d)
-.
Problem Possible cause Remedy Page
sough idle, stalls or Spark plugs faulty Inspect plugs IG-7
misses (cont’d)
Engine overheats Check cooling system ’ co-4
Low compression Check compression EM-26, 2;
Engine hesitates/ Vacuum leaks Repair as necessary
poor acceleration 0 PCV hoses
. (w/ EGR)
EGR valve
0 Intake manifold
’ 0 Air intake chamber .c
0 Throttle body
0 ISC valve
Pulling in air between air flow meter and Repair as necessary FI-96, 96
throttle body
Incorrect ignition timing Reset timing _ EM-1 7
Emission control system problem
(cold engine)
0 (w/ EGR)
EGR system always on Check EGR system
High-tension cord faulty Inspect cord 1G-6,
Fuel system clogged Check fuel system FI-7
Air cleaner clogged Check air cleaner EM-7
EFI system problems Repair as necessary
Spark plugs faulty Inspect plugs IG-7
Engine overheats Check cooling system co-4
Low compression Check compression EM-26, 2
Engine diesels EFI system problems Repair as necessary
(runs after ignition
switch is turned off)
Muffler explosion Deceleration fuel cut system always off Check EFI (fuel cut) system FI-128
(after fire) on
deceleration only
Muffler explosion Air cleaner clogged Check air cleaner EM-7
(after fire) all the time
EFI system problem Repair as necessary
incorrect ignition timing Reset timing EM-l.7
Engine backfires Vacuum leak Check hoses and repair as
l PCV hoses necessary
. (w/ EGR)
EGR valve c
0 Intake manifold
0 Air intake chamber
l Throttle body
0 ISC valve
Pulling in air between air flow meter and Repair as necessary Fl-96, 91
throttle body
EFI system problem Repair as necessary
Insufficient fuel flow Troubleshoot fuel system
Incorrect ignition timing Reset timing EM-l 7
Carbon deposits in combustion chambers Inspect cylinder head EM-97

EM-6 ENGINE MECHANICAL - Troubleshooting
Problem
:- Excessive oil
consumption
Poor fuel economy
Unpleasant odor -.
TROUBLESHOOTING (Cont’d) ._
Possible cause
Oil leak
PCV line clogged
Piston rings worn or damaged
Valve stem and guide worn
Valve stem seal worn
Fuel leak
Air cleaner clogged
Incorrect ignition timing
EFI system problems
l Injector faulty
0 Deceleration fuel cut system faulty
Idle speed too high
Spark plugs faulty
EGR system always on
Low compression
Tires improperly inflated
Clutch slips
Brakes drag
Incorrect idle speed
Incorrect ignition timing
‘Vacuum leaks
0 PCV hoses
0 (w/ EGR)
EGR valve ’
0 Intake manifold
l Air intake chamber
l Throttle body
EFI system problems Remedy
Repair as necessary
Check PCV system
Check rings
Check valves
Check seals ~’
Repair as necessary
Check air cleaner
Reset timing
Repair as necessary
Check ISC system
Inspect plugs
Check EGR system
Check compression
Inflate tires to proper pressun
Troubleshoot clutch
Troubleshoot brakes
Check ISC system
Reset timing
Repair as necessary
Repair as necessary Page
EM-65
EM-37
EM-37
EM-7
EM-l 7
FI-108
IG-7
M-26, 2’
FI-108
EM-l 7