Mitsubishi 3000GT Service Manual page 249

TROUBLESHOOTING HINTS
Hint 1: If the engine is hard to start when hot, check fuel pressure and check the injector for leaks.
Hint 2: If the injector does not operate when the engine that is hard to start is cranked, the following
as well as the injector itself may be responsible.
(1) Faulty power supply circuit to the engine control unit, faulty ground circuit
(2) Faulty MFI relay
(3) Faulty crankshaft position sensor, camshaft position sensor
Hint 3: If there is any cylinder whose idle state remains unchanged when the fuel injection of injectors
is cut one after another during idling, make following checks about such cylinder.
(1) Injector and harness check
(2) Ignition plug and high tension cable check
(3) Compression pressure check
Hint 4: If the injector harness and individual part checked good but the injector drive time is out of specifica-
tion, the following troubles are suspected.
(1) Poor combustion in the cylinder (faulty ignition plug, ignition coil, compression pressure, etc.)
(2) Loose EGR valve seating
(3) High engine resistance
INSPECTION
Using Scan Tool
Function Item No. Data display
Drive time"
Data 41
reading
Function Item No. Data display
Drive time'3
Data 41
reading
NOTE
rpm.
l 3: When the vehicle is new [within initial operation of about 500 km (300 miles)], the injector drive time may be
about 10% longer.
item No.
Function
01
Actuator test
02
03
04
05
06
MULTIPORT
On-Vehicle Inspection of MFI
FUEL INJECTION - Components
Check condition
Engine: Cranking
Check condition
l
Engine coolant tem-
perature: 80 to 95°C
(176 to 203°F)
l
Lights, electric cool-
ing fan, accessory
units: All OFF
Transaxle: Neutral
l
(P range for vehicle
with A/T)
wheel:
Neutral
Drive content
No.1 injector shut off
No.2 injector shut off
No.3 injector shut off
No.4 injector shut off
No.5 iniector shut off
I
No.6 injector shut off
TSB Revision
Coolant tem-
Standard value
perature
0°C (32"F)*2
40-48.8 ms <From 1994 models>
9.9-12.1 ms <Up to 1993 models>
86-l 0.6 ms <From 1994 models>
Engine state
700 rpm (Idle) 2.3-3.5 ms
2,000 rpm 2.0-3.2 ms
made
Check condition
Engine: Idling after
warm-up
(Shut off the injectors
in sequence during idling
after engine warm-up,
check the idling condi-
tion)
Standard value
Normal state
Idle state to change
further (becoming less
stable or stalling)