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.
1-12 EFI SYSTEM - Troubleshooting’
FlO48
TROUBLESH~~TI~~G
. .
TROUBLESHOOTING HlhJTS
1. Engine troubles are usually not caused by the EFI system.
When troubleshooting, always first check the condition of
the other systems.
(a) Electronic source
0 Battery
0 Fusible links
0 Fuses
(b) Body ground
(cl Fuel supply
0 Fuel leakage
0 Fuel filter
0 Fuel pump
(d) Ignition system
0 Spark plug
0 High-tension cord
l Distributor (7M-GE) or cam position sensor (7M-
GTE)
0 Igniter and ignition coil
(e) Air induction system
0 Vacuum leaks
(f) Emission control system
0 PCV system
0 EGR system (w/ EGR)
(g) Others
l Ignition timing (ESA system)
0 Idle speed (ISC system)
-r
2. The most frequent cause of problems is simply a bad don-
tact in wiring connectors. Always make sure that connec-
tions are secure.
When inspecting the connector, pay particular attention to
the following points:
(a) Check to see that the terminals are not bent.
(b) Check to see that the connector is pushed in com-
pletely and locked.
(c) Check to see that there is no signal change when the
connector is slightly tapped or wiggled.
3. Sufficiently troubleshoot for other causes before replac-
ing the ECU. The ECU is of high quality and it is expensive.
EFI SYSTEM - Troubleshootina
SYMPTOM - DIFFICULT TO START O-R NO START (CRANKS OK)
CHECK DIAGNOSIS SYSTEM
Check for output of diagnostic code.
(See page FI-26) Diagnostic code(s) (See pages FI-30,‘31,32)
Normal code
DOES ENGINE’START WITH
ACCELERATORPEDALDEPRESSED? OK ISC system
0) ISC valve
(2) Wiring connection
i NO I
CHECK FOR VACUUM LEAKS IN AIR I
BAD
INTAKE LINE
I OK
CHECK IGNITION SPARK ’
7M-GE (See page IO-61
7M-GTE (See page IG-12)
t OK
CHECKSPARKPLUGS
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
valve clearance if necessary.
OK CONTINUED ON PAGE FI-15
!
I
.
BAD 1. Oil filler cap
2. Oil dipstick
3. Hose connections
4. PCV hose
5. (w/ EGR)
EGR system - EGR valve stays open
1. High-tension cords
2. Distributor (‘IM-GE) or cam position
sensor (7M-GTE)
3. Ignition coil
4. Igniter
+
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 0.16 - 0.25 mm
(0.008 - 0.010 in.)
EX 0.20 - 0.30 mm
(0.008 - 0.012 in.1
1. Injector - shorted or leaking
2. Injector wiring between resistor and
ECU shorted
3. Cold start injector - Leakage
(See page Fl-80)
4. Cold start injector time switch
(See page Fl-115)
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.)
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-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
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
EFI SYSTEM
- Diagnosis System
FI-31
DIAGNOSTIC CODES (MA) (Cont’d) __
:odc
No. Number of
Check engine
blinks Diagnosis System See
page
FL50 Trouble area
l Vehicle speed sensor
circuit
l Vehicle speed sensor
. ECU ’
I
l Ignition switch circuit
l Ignition switch
l ECU
l Knock sensor circuit
l Knock sensor
l ECU
. ECU
l A/C switch circuit
l A/C switch ‘“q
l A/C am&fire
l Neutral start switch
circuit ’
l Neutral start switch
0 Throttle position sensor
circuit
l Throttle position sensor
l ECU Vehicle Speed
Sensor Signal
Starter Signal No “SPD” signal for 5
seconds when engine speed
is between 2,500 rpm and
4,500 rpm and coolant temp.
is below 80°C (176’F) except
when racing the engine.
No “STA” signal to ECU until
engine speed reaches 800
rpm with vehicle not moving.
Knock Sensor
Signal Open or short circuit in knock
sensor signal. 42
FI161
FHBl
Fl181
FIlei
52
Knock control in ECU faulty. Knock Control
signal in ECU
No “IDL” signal, “NSW”
signal or “A/C” signal to
ECU, with check terminals
El and T shorted. Switch Signal
‘1 WI TWC vehicles only
‘2 7M-GTE only
“3 Abnormalities in the air flow meter may also be detected.
DIAGNOSTIC CODES (MS)
Number of
Check engine
System
blinks
m Normal
fl1604
nn ECU (B) Diagnosis
This appears when none of
the other codes are identified.
Momentary interruption in
power supply to ECU. Trouble area See
page
l Ignition switch circuit
l Ignition switch
l Main relay circuit
l Main relay
l ECU FI-62
l Distributor circuit
0 Distributor
l Starter signal circuit
. ECU IG-3
l Distributor circuit
l Distributor
. ECU IG-3
l Igniter and ignition coil 11
FI1605
n nn RPM Signal No “NE” or “G” signal to
ECU within 2 seconds after
engine has been cranked.
FHBOB
nnnn, RPM Signal No “NE” signal to ECU when
engine speed is above
Fl1807 1,000 rpm. 12
-
13
-
14
-LJUlJUL 1 Ignition Signal 1 * No. “IGF” signal to ECU
6 - 8 times in succession. circuit
0 Igniter and ignition coil
. ECU
.t Fl-70