1900 MITSUBISHI DIAMANTE oil temperature

DRIVETRAIN 7-11
Fig. 45 location of 4-wheel steering oil
l Park/neutral switch electrical harness l Kickdown servo switch l Pulse generator l Oil temperature sensor electrical harness l Shift control solenoid valve harness.
19. Support the transaxle and remove the
transaxle mounting bracket.
20. Remove the three upper transaxle-to-engine
mounting bolts.
21. For vehicles with 4WS, remove the heat
shield for the 4WS oil pump and remove the pump.
Do not allow the pump to hang from the oil hoses.
22. For vehicles equipped with Active-ECS, dis-
connect the height sensor rod from the lower control
arm.
23. Remove the bolt that secures the Heated Oxy-
gen (HOaS) sensor harness to the right side cross-
member.
’ 24. Remove the starter assembly.
25. Remove the mounting brackets for access to
the bell housing cover,
26. Remove the bell housing/oil pan covers as-
sembly. 27. Remove the bolts holding the flexplate to the
torque converter.
28. Remove the lower transaxle to engine bolts
and remove the transaxle assembly.
To install: 29. Install the transaxle assembly to the engine
block, install the mounting bolts and tighten to 54 ft.
tbs. (75 Nm).
30. Install the bolts that secure the torque con-
verter to the driveplate. Tighten the bolts to 34-38 ft.
Ibs (4653 Nm).
31. Install the bell housing/oil pan covers.
32. Install the transaxle stay brackets that were
removed for access to the bell housing cover.
33. Install the starter assembly and connect the
wiring.
34. Install the bolt that secures the HO& sensor
harness to the right side crossmember and tighten
the bolt to 7-9 ft. Ibs. (X-12 Nm).
35. For vehicles equipped with Active-ECS, con-
nect the height sensor rod from the lower control’
arm. Check the height sensor rod for a length (A) of
10.59-10.63 in. (269-270mm)
36. If removed, install the 4WS oil pump and
tighten the mounting bolts to 17 ft. Ibs. (24 Nm).
37. If removed, install the 4WS oil pump heat
shield and tighten the mounting bolts to 17 ft. Ibs.
(24 Nm).
38. Install the three upper transaxle-to-engine
mounting bolts. Tighten the mounting bolts to 54 ft.
Ibs. (75 Nm).
*One of the upper bolts has a grounding
strap to secure under the bolt.
39. Install and connect the transaxle mounting
bracket. Tighten the mounting nut and bolts to 51 ft.
Ibs. (70 Nm).
40. Connect the shift control solenoid valve har-
ness
Removal steps 1. Transaxle control cable connection
2. Transaxle 011 cooler hoses connection
3. PNP swrtch connector
4. FvT control solenoid valve connector
5. Input shaft speed sensor connector
6. Output shaft speed sensor connector
7. Vehicle speed sensor connector
6. Spht pin
9. Connection of the tie rod end
10. Drwe shaft nut 11. Connectton for the lower arm ball
jomt
12. Drwe shaft and inner shaft assembly
(RH) and the drwe shaft (LH)
Caution
Mounting locations marked by
l should be
provisionally tightened, and then fully tightened
when the body is supporting the full weight of the
engine.
7923PG84
:io. 46 Transaxie removal (1 of 2)-Diamante with F4A51 transaxie
41. Connect the kickdown servo switch, pulse
generator and oil temperature sensor electrical har-
ness
42. Connect the park/neutral switch electrical
harness.
43. Using new hose clamps, install the oil cooler
hoses to the transaxle.
44. Install shifter control cable to the transaxle
and secure the cable with clip.
45. Connect the speedometer cable to the
transaxle.
46. If removed, install the roll stopper stay
bracket and tighten the one through nut and bolt to
36-43 ft. Ibs. (50-60 Nm). Tighten the two mounting
bolts to 16 ft. Ibs. (22 Nm).
47. If removed, install the Active-ECS compres-
sor assembly. Tighten the mounting bolts to 48 inch
Ibs. (5 Nm) and connect the electrical harness.
48. Attach the engine harness connection.
49. Install the air cleaner assembly and adjoining
duct work.
50. Using new circlips, install the halfshafts and
seat halfshafts into the transaxle. Install the bolt that
secure the left side support bearing and tighten the
bolts to 33 ft. Ibs. (45 Nm).
51. Connect the ball joint and tie rod end to the
steering knuckle. Using new nuts, tighten the ball
joint castle nut to 43-52 ft. Ibs. (60-72 Nm) and
tighten the tie rod castle nut to 22 ft. ibs. (30 Nm). in-
stall new cotter pins.
52. Using new gaskets, install the exhaust sys-
tem.
53. If removed, install front catalytic converter.
54. Install the engine undercovers.
55. Connect the negative battery cable.
56. Fill the transaxle to the correct level.
57. Start the engine and check for leaks.
Gaiant
1999-1993 MODELS
1. On vehicles equipped with auto-cruise, re-
move the control actuator and bracket.
2. If equipped with an active ECS, disconnect
the air compressor.
3. Drain the transaxle fluid into a suitable con-
tainer.
4. Remove the air cleaner assembly, intercooler
and air hose, as required.
5. Mark the shift cable. Remove the adjusting
nut and disconnect the shift cable.
6. Tag and detach the electrical connectors for
the solenoid, neutral safety switch (inhibitor switch),
the pulse generator kickdown servo switch and oil
temperature sensor.
7. Disconnect the speedometer cable and oil
cooler lines.
8. Disconnect the wires to the starter motor and
remove the starter.
9. Remove the upper transaxle to engine bolts.
10. Support the transaxle and remove the
transaxle mounting bracket.
11. Raise the vehicle and support safely. Remove
the sheet metal under guard
12. Remove the tie rod ends and the bail joints
from the steering knuckle.
13. Remove the halfshafts by inserting a prybar
between the transaxle case and the driveshaft and
prying the shaft from the transaxle. Do not pull on the
driveshaft. Doing so damages the inboard joint. Use

.
7-12 DRIVETRAIN
26-33Nm
19 - 24 itlbs.
45 - 52 Nm
69 Nm
51 ftlbs.

66 Nm
65 ftlbs.
52 Nm
36 fl.lbs.
:ig.
the prybar. Do not insert the prybar so far the oil seal
in the case is damaged. Tie the halfshafts aside.
14. On AWD vehicles, disconnect the exhaust
pipe and remove the transfer case.
15. Remove the lower bellhousing cover and re-
move the special bolts holding the flexplate to the
torque converter. To remove, turn the engine crank-
shaft with a box wrench and bring the bolts into a po-
sition appropriate for removal, one at a time. After re-
moving the bolts, push the torque converter toward
the transaxle so it doesn’t stay on the engine allowing
oil to pour out the converter hub or cause damage to
the converter,
16. Remove the lower transaxle to engine bolts
and remove the transaxle assembly. To install: 17. After the torque converter has been mounted
on the transaxle, install the transaxle assembly on the
engine. Tighten the driveplate bolts to 34-38 ft. Ibs.
(4653 Nm). Tighten the transaxle-to-engine bolts to
35 ft. Ibs. (48 Nm). Install the bellhousing cover.
18. On AWD vehicles, install the transfer case
and frame pieces. Connect the exhaust pipe using a
new gasket.
19. Replace the circlips and install the halfshafts
to the transaxle.
20. Install the tie rods and ball joint to the steer-
ing arm.
21. Install the transaxle mounting bracket.
22. install the under guard.
23. Install the starter.
24. Connect the speedometer cable and oil cooler
lines.
25 Connect the solenoid, neutral safety switch
(inhibitor switch), the pulse generator kickdown
servo switch and oil temperature sensor.
26. Install the shift control cable.
27. Install the air hose, intercooler and air cleaner
assembly.
If equipped with an active ECS, connect the
mante with a F4A33 automatic transaxle
30 Refill with Dexron II, Mopar ATF Plus type
7176, Mitsubishi Plus ATF or equivalent, automatic
transaxle fluid. If vehicle is AWD check and fill the
transfer case.
31. Start the engine and allow to idle for 2 min-
utes. Apply parkrng brake and move selector through
each gear posrtion, ending in N. Recheck fluid level
and add if necessary. Fluid level should be between
the marks in the HOT range.
1994-90 MODELS
1. Disconnect the negative battery cable.
2. Remove the air cleaner and intake hoses.
3. Drain the transaxle into a suitable waste con-
tainer.
4. Remove the nut securing the shifter lever to
the transaxle. Remove the cable retaining clip and re-
move the cable from the transaxle.
5. Remove the shifter cable mounting bracket,
6. Tag and detach the electrical connectors for
the speedometer, solenoid, neutral safety switch (in-
hibitor switch), the pulse generator, kickdown servo
switch, and the oil temperature sensor.
7. Tag and disconnect the oil cooler lines at the
transaxle.
8. Remove the bolt securing the fluid dipstick
tube to the transaxle. Remove the dipstrck and tube
from the transaxle.
9. Remove the starter motor and position it
aside.
10. Using special tool MZ203827 or equivalent,
support the engine assembly.
11. Remove the rear roll stopper mounting
bracket.
12. Remove the transaxle mount bracket.
13. Remove the upper transaxle mounting bolts.
14. Raise and safely support the vehicle.
15. Remove the front wheel assemblies.
16. Remove the right hand undercover.
17. Remove and discard the cotter pin, then dis-
connect the tie rod end from the steering knuckle,
18. Disconnect the stabilizer bar link from the
damper fork.
19. Disconnect the damper fork from the lateral
lower control arm.
20. Disconnect the lateral lower arm, and the
compression arm lower ball joints from the steering
knuckle.
21. Pry the halfshafts from the transaxle, and se-
cure aside.
22. Remove the cover from the transaxle bell-
housing.
23. Remove the engine front roll stopper
through-bolt.
24. Remove the crossmember and the triangular
right hand stay.
25. Remove the bolts holding the flexplate to the
torque converter with a box wrench Rotate the engine
to bring the bolts into a position appropriate for re-
moval, one at a time. After removing the bolts, push
the torque converter toward the transaxle. This will
prevent the converter from remaining intact with the
engine, possibly damaging the converter,
26. Support the transaxle, using a transmission
jack, and remove the transaxle lower coupling bolt.
*The coupling bolt threads from the engine
side, into the transaxle, and is located just
above the halfshafl opening.

DRIVETRAIN 7-13
27. Shde the transaxle rearward and carefully
lower it from the vehicle.
To install: 28. After the torque converter has been mounted
on the transaxle, install the transaxle assembly to the
engine. Install the mounting bolts and tighten to 35
ft. Ibs. (48 Nm).
29. Install the transaxle lower coupling bolt and
tighten to 21-25 ft Ibs. (29-34 Nm).
30. Connect the torque converter to the flexplate
and tighten the bolts to 33-38 ft. Ibs. (45-52 Nm).
31. Install the cover to the transaxle bellhous-
ing and tighten the mounting bolts to 7 ft. Ibs. (9
Nm).
32 Install the crossmember and tighten the front
mounting bolts to 65 ft. Ibs (88 Nm) and the rear
bolt to 54 ft. Ibs. (73 Nm) Install the front engine roll
stopper through-bolt and lightly tighten. Once the full
weight of the engine is on the mounts, tighten the ’
bolt to 42 ft. Ibs. (57 Nm),
33. Install the triangular stay bracket and tighten
the mounting bolts to 65 ft. Ibs. (88 Nm).
34. Install the halfshafts, using new circlips on
the axle ends.
When installing the axleshaft, keep the in-
board joint straight in relation to the axle, so
as not to damage the oil seal lip of the
transaxle with the serrated part of the half-
shaft.
35. Connect the tie rod and ball joints to the
steering knuckle. Tighten the ball joint self-locking
nuts to 48 ft. Ibs. (65 Nm). Tighten the tie rod end nut
to 21 ft. Ibs. (28 Nm) and secure with a new cotter
pin.
36. Connect the damper fork to the lower control
arm and tighten the through-bolt to 65 ft Ibs. (88
Nm).
37. Connect the stabilizer link to the damper fork,
and tighten the self-locking nut to 29 ft. Ibs. (39 Nm).
38. Install the undercover.
39. Install the wheels and carefully lower the ve-
hicle
40. Install the transaxle mount bracket to the
transaxle, and tighten the mounting nuts to 32 ft. Ibs.
(43 Nm).
41. Install the rear roll stopper mounting bracket.
42. Remove the engine support. Tighten the
transaxle mount through-bolt to 51 ft. Ibs. (69 Nm)
and tighten the front engine roll stopper through-bolt.
43. Install the upper transaxle mounting bolts
and tighten to 35 fl. Ibs. (48 Nm).
44. Install the starter motor.
45. Install the dipstick tube and the dipstick
46. Install the shifter cable mounting bracket.
47. Connect the shifter lever and tighten the re-
taining nut to 14 ft. Ibs. (19 Nm).
48. Connect the oil cooler lines and secure with
clamps.
49. Attach the electrical connectors for the
speedometer, solenoid, neutral safety switch (in-,
hibitor switch), the pulse generator, kickdown servo
switch and oil temperature sensor.
50. Install the air cleaner and the air intake hose.
51. Connect the negative battery cable.
52. Make sure the vehicle is level, and refill the
transaxle. Start the engine and allow to idle for 2 minutes. Apply parking brake and move selector
through each gear position, ending in N. Recheck
fluid level and add if necessary. Fluid level should be
between the marks in the HOT range.
53. Check the transaxle for proper operation.
Make sure the reverse lights come on when in re-
verse and the engine starts only in
P or N.
Mirage
*If the vehicle is going to be rolled on its
wheels while the halfshafts are out of the ve-
hicle, obtain two outer CV-joints or proper
equivalent tools and install to the hubs. If the
vehicle is rolled without the proper torque
applied to the front wheel bearings, the bear-
ings will no longer be usable.
1. Disconnect the negative battery cable then
the positive battery cable.
2. Remove the battery and battery tray.
3. Remove the air hose and air cleaner assem-
bly.
4. Raise the vehicle and support safely.
5. Remove the under guard pan.
6. Drain the transaxle oil into a suitable con-
tainer.
7. If equipped with 1.6L engine, remove the ten-
sion rod.
8. Disconnect the control cable and cooler
lines.
9. On 3-speed transaxles, disconnect the throt-
tle control cable.
10. On 4-speed transaxles, perform the following:
a. Detach the shift control solenoid valve
connector.
b. Disconnect the inhibitor switch and kick-
down servo switch.
c. Disconnect the pulse generator and oil
temperature sensor.
11. Disconnect the speedometer cable and re-
move the starter.
12. Remove the transaxle mounting bolts and
bracket.
13. Disconnect the stabilizer bar from the lower
control arm.
14. Disconnect the steering tie rod end and the
ball joint from the steering arm.
15. Remove the halfshafts at the inboard side
from the transaxle. Tie the joint assembly aside.
*It is not necessary to disconnect the half-
shafts from the wheel hubs.
16. Support the engine and remove the center
member.
17. Remove the bellhousing cover and remove
the driveplate bolts.
18 Remove the transaxle assembly lower con-
necting bolt, located just over the halfshaft opening.
19. Properly support the transaxle assembly, then
lower it, moving it to the right for clearance.
To install: 20. After the torque converter has been mounted
on the transaxle, install the transaxle assembly on the
engine. Install the mounting bolts and tighten to
31-40 ft. Ibs. (43-55 Nm) on 1990-92 models and
35 ft. Ibs. (48 Nm) on 1993-00 models.
21. Tighten the driveplate bolts to 33-38 ft. Ibs.
(46-53 Nm). Install the bellhousing cover.
22. Install the center member. 23. Replace the circlips and install the halfshafts
to the transaxle.
24. Install the tie rods, ball joints and stabilizer
links to the steering arm
25. Install the transaxle mounting bracket and
bolts.
26. Install the starter.
27. Connect the speedometer cable.
28. Connect the inhibitor switch, kickdown servo
switch, the pulse generator and oil temperature sen-
sor, if disconnected.
29. Connect the shift control solenoid valve con-
nector.
30. Connect the control cables and oil cooler
lines.
31. Install the tension rod, if removed.
32. Install the air cleaner assembly.
33. Install the battery tray and battery.
34. Connect the positive then the negative termi-
nal.
35. Refill with Dexron@ II, Mopar ATF Plus type
7176 or equivalent, automatic transaxle fluid.
36. Start the engine and allow to idle for two min-
utes. Apply parking brake and move selector through
each gear position, ending in N. Recheck fluid level
and add if necessary. Fluid level should be between
the marks in the HOT range.
ADJUSTMENTS
Shifter Control Cable Adjustment
1. The shifter cable adjustment is done at the
neutral safety switch (inhibitor switch). Locate the
switch on the transaxle and note the alignment holes
in the arm and the body of the switch. Place the se-
lector lever in N. Place the manual lever of the
transaxle in the neutral position.
2. Check alignment of the hole in the manual
control lever to the hole in the inhibitor switch body.
If the holes do not align, adjustment is required.
3. To adjust, loosen the nut on the cable end and
pull the cable end by hand until the alignment holes
match. Tighten the nut. Check that the transaxle
shifts and conforms to the positions of the selector
lever.
Throttle Valve Cable
The throttle valve adjustment applies only to the
1990-96 Mirage.
1. Place selector lever and manual control lever
in N position.
2. Loosen adjusting nut. While lightly pulling on
control cable tighten mounting nut to 7-10 ft. Ibs.
(X-14 Nm).
3. When adjustment is complete, be sure selector
lever is still in the N position. Verify all functions
correspond to the position indicated on the selector
lever.
The halfshaft removal and installation and over-
haul are the same as a manual transaxle Please refer
to Manual Transaxle in this Section

TROUBLESHOOTING INDEX 11-2
SECTION 1: ENGINE 11-2
SECTION 2: DRIVE TRAIN
11-3
SECTION 3:BRAKESYSTEM 11-3
SECTION 4:WHEELS,TIRES, STEERING,
AND SUSPENSION II-4
SECTION 5: ELECTRICAL
ACCESSORIES II-4
SECTION 6:lNSTRUMENTSAND
GAUGES II-5
SECTION 7:CLlMATE CONTROL II-5
DIAGNOSTIC PROCEDURES II-6
SECTION 1: ENGINE II-6
ENGINE STARTING PROBLEMS II-6
ENGINE RUNNING CONDITIONS II-7
ENGINE NOISES,ODORSAND
VIBRATIONS II-8
ENGINE ELECTRICALSYSTEM 11-8
ENGINE COOLING SYSTEM II-8
ENGINE EXHAUSTSYSTEM II-9
SECTION 2: DRIVE TRAIN
II-9
AUTOMATIC TRANSMISSION II-9
MANUALTRANSMISSION II-10
CLUTCH II-10
DIFFERENTIAL AND FINAL
DRIVE II-10
TRANSFER ASSEMBLY II-10
DRIVESHAFT II-10
AXLES II-II
OTHER DRIVE TRAIN
CONDITIONS II-II
SECTION 3:BRAKE SYSTEM II-II
BRAKESYSTEM
TROUBLESHOOTING II-II
SECTION 4:WHEELS, TIRES, STEERING
AND SUSPENSION II-12
WHEELSAND WHEEL
BEARINGS II-12
TIRES II-12
STEERING II-12
SUSPENSION II-12
DRIVING NOISES AND
VIBRATIONS II-13
SECTION 5:ELECTRlCAL
ACCESSORIES II-13 -
HEADLIGHTS II-13
TAIL, RUNNING AND SIDE MARKER
LIGHTS II-13
INTERIOR LIGHTS II-14
BRAKE LIGHTS II-14
WARNING LIGHTS II-14
TURN SlGNALAND4-WAYHAZARD
LIGHTS II-15
WINDSHIELD WIPERS II-15
SECTION 6:lNSTRUMENTSAND
GAUGUES II-15
I
SPEEDOMETER(CABLE
OPERATED) II-15
SPEEDOMETER(ELECTRONICALLY
OPERATED) II-16
FUEL,TEMPERATUREAkJD OIL
PRESSURE GAUGES II-16 SECTION 7:CLlMATECON
AIR CONDITIONER ll-
HEATER II-16 TR(
-16 IL II-16

II-6 TROUBLESHOOTING
DIAGhUSTIC PROCEDURES
Gasoline Engines
1. Engine turns over, but wilt not start
a. Check fuel level in fuel tank, add fuel if empty.
b. Check battery condition and state of charge. If voltage and load test below specifica-
tion, charge or replace battery.
c. Check battery terminal and cable condition and tightness. Clean terminals and replace
damaged, worn or corroded cables.
d. Check fuel delivery system. If fuel is not reaching the fuel injectors, check for a loose
electrical connector or defective fuse, relay or fuel pump and replace as necessary.
e. Engine may have excessive wear or mechanical damage such as low cylinder cranking
pressure, a broken camshaft drive system, insufficient valve clearance or bent valves.
f. Check for fuel contamination such as water in the fuel. During winter months, the wa-
ter may freeze and cause a fuel restriction. Adding a fuel additive may help, however
the fuel system may require draining and purging with fresh fuel.
g. Check for ignition system failure. Check for loose or shorted wires or damaged igni-
tion system components. Check the spark plugs for excessive wear or incorrect elec-
trode gap. If the problem is worse in wet weather, check for shorts between the spark
plugs and the ignition coils.
h. Check the engine management system for a failed sensor or control module.
2. Engine does not turn over when attempting to start
a. Check the battery state of charge and condition. If the dash lights are not visible or
very dim when turning the ignition key on, the battery has either failed internally or
discharged, the battery cables are loose, excessively corroded or damaged, or the al-
ternator has failed or internally shorted, discharging the battery. Charge or replacethe
battery, clean or replace the battery cables, and check the alternator output.
b. Check the operation of the neutral safety switch. On automatic transmission vehicles,
try starting the vehicle in both Park and Neutral. On manual transmission vehicles, de-
press the clutch pedal and attempt to start. On some vehicles, these switches can be
adjusted. Make sure the switches or wire connectors are not loose or damaged. Re-
place or adjust the switches as necessary.
c. Check the starter motor, starter solenoid or relay, and starter motor cables and wires.
Check the ground from the engine to the chassis. Make sure the wires are not loose,
damaged, or corroded. If battery voltage is present at the starter relay, try using a re-
mote starter to start the vehicle for test purposes only. Replace any damaged or cor-
roded cables, in addition to replacing any failed components.
d. Check the engine for seizure. If the engine has not been started for a long period of
time, internal parts such as the rings may have rusted to the cylinder walls. The engine
may have suffered internal damage, or could be hydro-locked from ingesting water.
Remove the spark plugs and carefully attempt to rotate the engine using a suitable
breaker bar and socket on the crankshaft pulley. If the engine is resistant to moving, or
moves slightly and then binds, do not force the engine any further before determining
the problem.
3. Enpine stalls immediately when started
a. Check the ignition switch condition and operation. The electrical contacts in the run
position may be worn or damaged. Try restarting the engine with all electrical acces-
sories in the off position. Sometimes turning the key on an off will help in emergency
situations, however once the switch has shown signs of failure, it should be replaced
as soon as possible.
b. Check for loose, corroded, damaged or shorted wires for the ignition system and re-
pair or replace.
c. Check for manifold vacuum leaks or vacuum hose leakage and repair or replace parts
as necessary.
d. Measure the fuel pump delivery volume and pressure. Low fuel pump pressure can
also be noticed as a lack of power when accelerating. Make sure the fuel pump lines
are not restricted. The fuel pump output is not adjustable and requires fuel pump re-
placement to repair.
e. Check the engine fuel and ignition management system. Inspect the sensor wiring and
electrical connectors. A dirty, loose or damaged sensor or control module wire can
simulate a failed component.
f. Check the exhaust system for internal restrictions.
4. Starter motor spins, but does not engage
a. Check the starter motor for a seized or binding pinion gear.
b. Remove the flywheel inspection plate and check for a damaged ring gear.
5. Engine is difficult to start when Gold
a. Check the battery condition, battery state of charge and starter motor current draw. Re-
place the battery if marginal and the starter motor if the current draw is beyond specifi-
cation. b. Check the battery cable condition. Clean the battery terminals and replace corroded or
damaged cables.
c. Check the fuel system for proper operation. A fuel pump with insufficient fuel pressure
or clogged injectors should be replaced.
d. Check the engine’s tune-up status. Note the tune-up specifications and check for items
such as severely worn spark plugs; adjust or replace as needed. On vehicles with
manually adjusted valve clearances, check for tight valves and adjust to specification.
e. Check for a failed coolant temperature sensor, and replace if out of specification.
f. Check the operation of the engine management systems for fuel and ignition; repair or
replace failed components as necessary.
6. En#ine is ditticutt to start when hot
a. Check the air filter and air intake system. Replace the air filter if it is dirty or contami-
nated. Check the fresh air intake system for restrictions or blockage.
b. Check for loose or deteriorated engine grounds and clean, tighten or replace as
needed.
c. Check for needed maintenance. Inspect tune-up and service related items such as
spark plugs and engine oil condition, and check the operation of the engine fuel and
ignition management system.
Diesel Engines
1. Engine turns over but won’t start
a. Check engine starting procedure and restart engine.
b. Check the glow plug operation and repair or replace as necessary.
c. Check for air in the fuel system or fuel filter and bleed the air as necessary.
d. Check the fuel delivery system and repair or replace as necessary.
e. Check fuel level and add fuel as needed.
f. Check fuel quality. If the fuel is contaminated, drain and flush the fuel tank.
g. Check engine compression. If compression is below specification, the engine may
need to be renewed or replaced.
h. Check the injection pump timing and set to specification.
i. Check the injection pump condition and replace as necessary.
j. Check the fuel nozzle operation and condition or replace as necessary.
2. Engine does
hot turn over when attempting to start
a. Check the battery state of charge and condition. If the dash lights are not visible or
very dim when turning the ignition key on, the battery has either failed internally or
discharged, the battery cables are loose, excessively corroded or damaged, or the al-
ternator has failed or internally shorted, discharging the battery. Charge or replace the
battery, clean or replace the battery cables, and check the alternator output.
b. Check the operation of the neutral safety switch. On automatic transmission vehicles,
try starting the vehicle in both Park and Neutral. On manual transmission vehicles, de-
press the clutch pedal and attempt to start. On some vehicles, these switches can be
adjusted. Make sure the switches or wire connectors are not loose or damaged. Re-
place or adjust the switches as necessary.
c. Check the starter motor, starter solenoid or relay, and starter motor cables and wires.
Check the ground from the engine to the chassis. Make sure the wires are not loose,
damaged, or corroded. If battery voltage is present at the starter relay, try using a re-
mote starter to start the vehicle for test purposes only. Replace any damaged or cor-
roded cables, in addition to replacing any failed components.
d. Check the engine for seizure. If the engine has not been started for a long period of
time, internal parts such as the rings may have rusted to the cylinder walls. The engine
may have suffered internal damage, or could be hydro-locked from ingesting water.
Remove the injectors and carefully attempt to rotate the engine using a suitable
breaker bar and socket on the crankshaft pulley. If the engine is resistant to moving, or
moves slightly and then binds, do not force the engine any further before determining
the cause of the problem.
3. Engine stalls afier starting
a. Check for a restriction in the fuel return line or the return line check valve and repair as
necessary.
b. Check the glow plug operation for turning the glow plugs off too soon and repair as
necessary.
c. Check for incorrect injection pump timing and reset to specification.
d. Test the engine fuel pump and replace if the output is below specification.
e. Check for contaminated or incorrect fuel. Completely flush the fuel system and replace
with fresh fuel.
f. Test the engine’s compression for low compression. If below specification, mechanical
repairs are necessary to repair.
g. Check for air in the fuel. Check fuel tank fuel and fill as needed.
h. Check for a failed injection pump. Replace the pump, making sure to properly set the
pump timing.

TROUBLESHOOiNG 11-7
4. Starter motor spins, but does not engage
a. Check the starter motor for a seized or binding pinion gear.
b. Remove the flywheel inspection plate and check for a damaged ring gear.
Gasoline Engines
1. Engine runs poor/y, hesiiates
a. Check the engine ignition system operation and adjust if possible, or replace defective
parts.
b. Check for restricted fuel injectors and replace as necessary.
c. Check the fuel pump output and delivery. Inspect fuel lines for restrictions. If the fuel
pump pressure is below specification, replace the fuel pump.
d. Check the operation of the engine management system and repair as necessary.
2. Enfline lacks power
a. Check the engine’s tune-up status. Note the tune-up specifications and check for items
such as severely worn spark plugs; adjust or replace as needed. On vehicles with
manually adjusted valve clearances, check for tight valves and adjust to specification.
b. Check the air filter and air intake system. Replace the air filter if it is dirty or contami-
nated. Check the fresh air intake system for restrictions or blockage.
c. Check the operation of the engine fuel and ignition management systems. Check the
sensor operation and wiring. Check for low fuel pump pressure and repair or replace
components as necessary.
d. Check the throttle linkage adjustments. Check to make sure the linkage is fully open-
ing the throttle. Replace any worn or defective bushings or linkages.
e. Check for a restricted exhaust system. Check for bent or crimped exhaust pipes, or in-
ternally restricted mufflers or catalytic converters. Compare inlet and outlet tempera-
tures for the converter or muffler. If the inlet is hot, but outlet cold, the component is
restricted.
f. Check for a loose or defective knock sensor. A loose, improperly torqued or defective
knock sensor will decrease spark advance and reduce power. Replace defective knock
sensors and install using the recommended torque specification.
g. Check for engine mechanical conditions such as low compression, worn piston rings,
worn valves, worn camshafts and related parts. An engine which has severe mechani-
cal wear, or has suffered internal mechanical damage must be rebuilt or replaced to re-
store lost power.
h. Check the engine oil level for being overfilled. Adjust the engine’s oil level, or change
the engine oil and filter, and top off to the correct level.
i. Check for an intake manifold or vacuum hose leak. Replace leaking gaskets or worn
vacuum hoses.
j. Check for dragging brakes and replace or repair as necessary.
k. Check tire air pressure and tire wear. Adjust the pressure to the recommended set-
tings. Check the tire wear for possible alignment problems causing increased rolling
resistance, decreased acceleration and increased fuel usage.
I. Check the octane rating of the fuel used during refilling, and use a higher octane rated
fuel.
3. Poor fuel economy
a. Inspect the air filter and check for any air restrictions going into the air filter housing.
Replace the air filter if it is dirty or contaminated.
b. Check the engine for tune-up and related adjustments. Replace worn ignition parts,
check the engine ignition timing and fuel mixture, and set to specifications if possible.
c. Check the tire size, tire wear, alignment and tire pressure. Large tires create more
rolling resistance, smaller tires require more engine speed to maintain a vehicle’s road
speed. Excessive tire wear can be caused by incorrect tire pressure, incorrect wheel
alignment or a suspension problem. All of these conditions create increased rolling
resistance, causing the engine to work harder to accelerate and maintain a vehicle’s
speed.
d. Inspect the brakes for binding or excessive drag. A sticking brake caliper, overly ad-
justed brake shoe, broken brake shoe return spring, or binding parking brake cable or
linkage can create a significant drag, brake wear and loss of fuel economy. Check the
brake system operation and repair as necessary.
4. Engine runs on (diesels) when turned off
a. Check for idle speed set too high and readjust to specification.
b. Check the operation of the idle control valve, and replace if defective.
c. Check the ignition timing and adjust to recommended settings.
Check for defective
sensors or related components and replace if defective.
d. Check for a vacuum leak at the intake manifold or vacuum hose
and replace defective
gaskets or hoses.
e. Check the engine for excessive carbon build-up in the combustion chamber. Use a
recommended decarbonizing fuel additive or disassemble the cylinder head to remove
the carbon.
f. Check the operation of the engine fuel management system and replace defective sen-
sors or control units.
g. Check the engine operating temperature for overheating and repair as necessary. 5. Engine knocks and pinfls during heavy accele/ation, and on steep hills
a. Check the octane rating of the fuel used during refilling, and use a higher octane rated
fuel.
b. Check the ignition timing and adjust to recommended settings. Check for defective
sensors or related components and replace if defective.
c. Check the engine for excessive carbon build-up in the combustion chamber. Use a
recommended decarbonizing fuel additive or disassemble the cylinder head to remove
the carbon.
d. Check the spark plugs for the correct type, electrode gap and heat range. Replace worn
or damaged spark plugs. For severe or continuous high speed use, install a spark plug
that is one heat range colder.
e. Check the operation of the engine fuel management system and replace defective sen-
sors or control units.
f. Check for a restricted exhaust system. Check for bent or crimped exhaust pipes, or in-
ternally restricted mufflers or catalytic converters. Compare inlet and outlet tempera-
tures for the converter or muffler. If the inlet is hot, but outlet cold, the component is
restricted.
6. Engine atxelerates, but vehicle does not gain speed
a. On manual transmission vehicles, check for causes of a slipping clutch. Refer to the
clutch troubleshooting section for additional information.
b. On automatic transmission vehicles, check for a slipping transmission” Check the
transmission fluid level and condition. If the fluid level is too high, adjust to the cor-
rect level. If the fluid level is low, top off using the recommended fluid type. If the fluid
exhibits a burning odor, the transmission has been slipping internally. Changing the
fluid and filter may help temporarily, however in this situation a transmission may re-
quire overhauling to ensure long-term reliability.
Diesel Engines
1. Engine runs pOOr!y a. Check the injection pump timing and adjust to specification.
b. Check for air in the fuel lines or leaks, and bleed the air from the fuel system.
c. Check the fuel filter, fuel feed and return lines for a restriction and repair as necessary.
d. Check the fuel for contamination, drain and flush the fuel tank and replenish with fresh
fuel.
2. Enfline lacks power
a. Inspect the air intake system and air filter for restrictions and, if necessary, replace the
air filter.
b. Verify the injection pump timing and reset if out of specification.
c. Check the exhaust for an internal restriction and replace failed parts.
d. Check for a restricted fuel filter and, if restricted, replace the filter.
e. Inspect the fuel filler cap vent. When removing the filler cap, listen for excessive hiss-
ing noises indicating a blockage in the fuel filler cap vents, If the filler cap vents are
blocked, replace the cap.
f. Check the fuel system for restrictions and repair as necessary.
g. Check for low engine compression and inspect for external leakage at the glow plugs
or nozzles. If no external leakage is noted, repair or replace the engine.
ENGINE PERFORMANCE TROUBLESHOOTING HINTS When troubleshooting an engine running or performance condition, the mechanical
condition of the engine should be determined before lengthy troubleshooting procedures
are performed.
The engine fuel management systems in fuel injected vehicles rely on electronic sen-
sors to provide information to the engine control unit for precise fuel metering. Unlike
carburetors, which use the incoming air speed to draw fuel through the fuel metering jets
in order to provide a proper fuel-to-air ratio, a fuel injection system provides a specific
amount of fuel which is introduced by the fuel injectors into the intake manifold or intake
port, based on the information provided by electronic sensors.
The sensors monitor the engine’s operating temperature, ambient temperature and the
amount of air entering the engine, engine speed and throttle position to provide informa-
tion to the engine control unit, which, in turn, operates the fuel injectors by electrical
pulses. The sensors provide information to the engine control unit using low voltage
electrical signals. As a result, an unplugged sensor or a poor electrical contact could
cause a poor running condition similar to a failed sensor.
When troubleshooting a fuel related engine condition on fuel injected vehicles, care-
fully inspect the wiring and electrical connectors to the related components. Make sure
the electrical connectors are fully connected, clean and not physically damaged. If neces-
sary, clean the electrical contacts using electrical contact cleaner. The use of cleaning
agents not specifically designed for electrical contacts should not be used, as they could
leave a surface film or damage the insulation of the wiring.
The engine electrical system provides the necessary electrical power to operate the ve-
hicle’s electrical accessories, electronic control units and sensors. Because engine man-
agement systems are sensitive to voltage changes, an alternator which over or under-
charges could cause engine running problems or component failure. Most alternators
utilize internal voltage regulators which cannot be adjusted and must be replaced indi-
vidually or as a unit with the alternator.

11-8 TROUBLESHOOTING
Ignition systems may be controlled by, or linked to, the engine fuel management sys-
tem. Similar to the fuel injection system, these ignition systems rely on electronic sen-
sors for information to determine the optimum ignition timing for a given engine speed
and load. Some ignition systems no longer allow the ignition timing to be adjusted.
Feedback from low voltage electrical sensors provide information to the control unit to
determine the amount of ignition advance. On these systems, if a failure occurs the failed
component must be replaced. Before replacing suspected failed electrical components,
carefully inspect the wiring and electrical connectors to the related components. Make
sure the electrical connectors are fully connected, clean and not physically damaged. If
necessary, clean the electrical contacts using electrical contact cleaner. The use of clean-
ing agents not specifically designed for electrical contacts should be avoided, as they
could leave a surface film or damage the insulation of the wiring.
1. Engine makes a knocking or pinging noise when accelerating
a. Check the octane rating of the fuel being used. Depending on the type of driving or
driving conditions, it may be necessary to use a higher octane fuel.
b. Verify the ignition system settings and operation. Improperly adjusted ignition timing
or a failed component, such as a knock sensor, may cause the ignition timing to ad-
vance excessively or prematurely. Check the ignition system operation and adjust, or
replace components as needed.
c. Check the spark plug gap, heat range and condition. If the vehicle is operated in se-
vere operating conditions or at continuous high speeds, use a colder heat range spark
plug. Adjust the spark plug gap to the manufacturer’s recommended specification and
replace worn or damaged spark plugs.
2. Sfarter motor grinds when used
a. Examine the starter pinion gear and the engine ring gear for damage, and replace dam-
aged parts.
b. Check the starter mounting bolts and housing. If the housing is cracked or damaged
replace the starter motor and check the mounting bolts for tightness.
3. Engine makes a screeching noise
a. Check the accessory drive belts for looseness and adjust as necessary.
b. Check the accessory drive belt tensioners for seizing or excessive bearing noises and
replace if loose, binding, or excessively noisy.
c. Check for a seizing water pump. The pump may not be leaking; however, the bearing
may be faulty or the impeller loose and jammed. Replace the water pump.
4. Engine makes a growling noise
a. Check for a loose or failing water pump. Replace the pump and engine coolant.
b. Check the accessory drive belt tensioners for excessive bearing noises and replace if
loose or excessively noisy.
5. Engine makes a ticking or tapping noise
a. On vehicles with hydraulic lash adjusters, check for low or dirty engine oil and top off
or replace the engine oil and filter.
b. On vehicles with hydraulic lash adjusters, check for collapsed lifters and replace failed
components.
c. On vehicles with hydraulic lash adjusters, check for low oil pressure caused by a re-
stricted oil filter, worn engine oil pump, or oil pressure relief valve.
d. On vehicles with manually adjusted valves, check for excessive valve clearance or
worn valve train parts. Adjust the valves to specification or replace worn and defective
parts.
e. Check for a loose or improperly tensioned timing belt or timing chain and adjust or re-
place parts as necessary.
f. Check for a bent or sticking exhaust or intake valve. Remove the engine cylinder head
to access and replace.
6. Engine makes a heavy knocking noise
a. Check for a loose crankshaft pulley or flywheel; replace and torque the mounting
bolt(s) to specification.
b. Check for a bent connecting rod caused by a hydro-lock condition. Engine disassem-
bly is necessary to inspect for damaged and needed replacement parts.
c. Check for excessive engine rod bearing wear or damage. This condition is also asso-
ciated with low engine oil pressure and will require engine disassembly to inspect for
damaged and needed replacement parts,
7. Vehicle has a fuel odor when driven ’ a. Check the fuel gauge level. If the fuel gauge registers full, it is possible that the odor is
caused by being filled beyond capacity, or some spillage occurred during refueling.
The odor should clear after driving an hour, or twenty miles, allowing the vapor canis-
ter to purge.
b. Check the fuel filler cap for looseness or seepage. Check the cap tightness and, if
loose, properly secure. If seepage is noted, replace the filler cap.
c. Check for loose hose clamps, cracked or damaged fuel delivery and return lines, or
leaking components or seals, and replace or repair as necessary. d. Check the vehicle’s fuel economy. If fuel consumption has increased due to a failed
component, or if the fuel is not properly ignited due to an ignition related failure, the
catalytic converter may become contaminated. This condition may also trigger the
check engine warning light. Check the spark plugs for a dark, rich condition or verify
the condition by testing the vehicle’s emissions. Replace fuel fouled spark plugs, and
test and replace failed components as necessary.
5. Vehicle has a rotten egg odor when driven
a. Check for a leaking intake gasket or vacuum leak causing a lean running condition. A
lean mixture may result in increased exhaust temperatures, causing the catalytic con-
verter to run hotter than normal. This condition may also trigger the check engine
warning light. Check and repair the vacuum leaks as necessary.
b. Check the vehicle’s alternator and battery condition. If the alternator is overcharging,
the battery electrolyte can be boiled from the battery, and the battery casing may begin
to crack, swell or bulge, damaging or shorting the battery internally. If this has oc-
curred, neutralize the battery mounting area with a suitable baking soda and water
mixture or equivalent, and replace the alternator or voltage regulator. Inspect, service,
and load test the battery, and replace if necessary.
9. Vehicle has a sweet odor when driven
a. Check for an engine coolant leak caused by a seeping radiator cap, loose hose clamp,
weeping cooling system seal, gasket or cooling system hose and replace or repair as
needed.
b. Check for a coolant leak from the radiator, coolant reservoir, heater control valve or
under the dashboard from the heater core, and replace the failed part as necessary.
c. Check the engine’s exhaust for white smoke in addition to a sweet odor. The presence
of white, steamy smoke with a sweet odor indicates coolant leaking into the combus-
tion chamber. Possible causes include a failed head gasket, cracked engine block or
cylinder head. Other symptoms of this condition include a white paste build-up on the
inside of the oil filler cap, and softened, deformed or bulging radiator hoses.
19. Engine vibraies when idling
a. Check for loose, collapsed, or damaged engine or transmission mounts and repair or
replace as necessary.
b. Check for loose or damaged engine covers or shields and secure or replace as neces-
sary.
11. Engine vibrates during acceleration
a. Check for missing, loose or damaged exhaust system hangers and mounts; replace or
repair as necessary.
b. Check the exhaust system routing and fit for adequate clearance or potential rubbing;
repair or adjust as necessary.
7. Battery goes dead while driving
a. Check the battery condition. Replace the battery if the battery will not hold a charge or
fails a battery load test. If the battery loses fluid while driving, check for an overcharg-
ing condition. If the alternator is overcharging, replace the alternator or voltage regula-
tor. (A voltage regulator is typically built into the alternator, necessitating alternator re-
placement or overhaul.)
b. Check the battery cable condition. Clean or replace corroded cables and clean the bat-
tery terminals.
c. Check the alternator and voltage regulator operation. If the charging system is over or
undercharging, replace the alternator or voltage regulator, or both.
d. Inspect the wiring and wire connectors at the alternator for looseness, a missing .
ground or defective terminal, and repair as necessary.
e. Inspect the alternator drive belt tension, tensioners and condition. Properly tension the
drive belt, replace weak or broken tensioners, and replace the drive belt if worn or
cracked.
2. Battery goes dead overnight
a. Check the battery condition. Replace the battery if the battery will not hold a charge or
fails a battery load test.
b. Check for a voltage draw, such as a trunk light, interior light or glove box light staying
on. Check light switch position and operation, and replace if defective.
c. Check the alternator for an internally failed diode, and replace the alternator if defec-
tive.
1. Engine overheats
a. Check the coolant level. Set the heater temperature to full hot and check for internal air
pockets, bleed the cooling system and inspect for leakage. Top off the cooling system
with the correct coolant mixture.
b. Pressure test the cooling system and radiator cap for leaks. Check for seepage caused
by loose hose clamps, failed coolant hoses, and cooling system components such as
the heater control valve, heater core, radiator, radiator cap, and water pump. Replace
defective parts and fill the cooling system with the recommended coolant mixture.

GLOSSARY 11-17
AIR/FUEL RATIO: The ratio of air-to-gasoline by weight in the fuel mixture
drawn into the engine.
AIR INJECTION: One method of reducing harmful exhaust emissions by in-
jecting air into each of the exhaust ports of an engine. The fresh air entering
the hot exhaust manifold causes any remaining fuel to be burned before it can
exit the tailpipe.
ALTERNATOR: A device which produces AC (alternating current) which is
converted to DC (direct current) to charge the car battery.
AMMETER: An instrument, calibrated in amperes, used to measure the flow
of an electrical current in a circuit. Ammeters are always connected in series
with the circuit being tested.
AMPERE: The rate of flow of electrical current present when one volt of elec-
trical pressure is applied against one ohm of electrical resistance.
ANALOG COMPUTER: Any microprocessor that uses similar (analogous)
electrical signals to make its calculations.
ARMATURE: A laminated, soft iron core wrapped by a wire that converts elec-
trical energy to mechanical energy as in a motor or relay. When rotated in
a magnetic field, it changes mechanical energy into electrical energy as in a
generator.
ATMOSPHERIC PRESSURE: The pressure on the Earth’s surface caused
by the weight of the air in the atmosphere. At sea level, this pressure is 14.7
psi at 32°F (101 kPa at OOC).
ATOMIZATION: The breaking down of a liquid into a fine mist that can be
suspended in air.
AXIAL PLAY: Movement parallel to a shaft or bearing bore.
BACKFIRE: The sudden combustion of gases in the intake or exhaust sys-
tem that results in a loud explosion.
BACKLASH: The clearance or play between two parts, such as meshed gears.
BACKPRESSURE: Restrictions in the exhaust system that slow the exit of
exhaust gases from the combustion chamber.
BAKELITE[reg]: A heat resistant, plastic insulator material commonly used
in printed circuit boards and transistorized components.
BALL BEARING: A bearingmade up of hardened inner and outer races be-
tween which hardened steel’balls roll.
BALLAST RESISTOR: A resistor in the primary ignition circuit that lowers
voltage after the engine is started to reduce wear on ignition components.
BEARING: A friction reducing, supportive device usually located between a
stationary part and a moving part.
BI-METAL TEMPERATURE SENSOR: Anv sensor or switch made of two
dissimilar types of metal that bend when heated or cooled due to the different
expansion rates of the alloys. These types of sensors usually function as an
on/off switch. BLOW-BY: Combustion gases, composed of water vapor and unburned fuel,
that leak past the piston rings into the crankcase during normal engine oper-
ation. These gases are removed by the PCV system to prevent the buildup of
harmful acids in the crankcase.
BRAKE PAD: A brake shoe and lining assembly used with disc brakes.
BRAKE SHOE: The backing for the brake lining. The term is, however, usu-
ally applied to the assembly of the brake backing and lining.
BUSHING: A liner, usually removable, for a bearing; an anti-friction liner used
in place of a bearing.
CALIPER: A hydraulically activated device in a disc brake system, which is
mounted straddling the brake rotor (disc). The caliper contains at least one
piston and two brake pads. Hydraulic pressure on the piston(s) forces the pads
against the rotor.
CAMSHAFT: A shaft in the engine on which are the lobes (cams) which op-
erate the valves. The camshaft is driven by the crankshaft, via a belt, chain or
gears, at one half the crankshaft speed.
CAPACITOR: A device which stores an electrical charge.
CARBON MONOXIDE (CO): A colorless, odorless gas given off as a nor-
mal byproduct of combustion. It is poisonous and extremely dangerous in con-
fined areas, building up slowly to toxic levels without warning if adequate ven-
tilation is not available.
CARBURETOR: A device, usually mounted on the intake manifold of an en-
gine, which mixes the air and fuel in the proper proportion to allow even com-
bustion
CATALYTIC CONVERTER: A device installed in the exhaust system, like a
muffler, that converts harmful byproducts of combustion into carbon dioxide
and water vapor by means of a heat-producing chemical reaction.
CENTRIFUGAL ADVANCE: A mechanical method of advancing the spark
timing by using flyweights in the distributor that react to centrifugal force gen-
erated by the distributor shaft rotation.
CHECK VALVE: Any one-way valve installed to permit the flow of air, fuel or
vacuum in one direction only.
CHOKE: The valve/plate that restricts the amount of air entering an engine on
the induction stroke, thereby enriching the air:fuel ratio.
CIRCUIT: Any unbroken path through which an electrical current can flow.
Also used to describe fuel flow in some instances.
CIRCUIT BREAKER: A switch which protects an electrical circuit from
overload by opening the circuit when the current flow exceeds a pre-
determined level. Some circuit breakers must be reset manually, while most
reset automatically.
COIL (IGNITION): Part of the ignition system that boosts the relatively low
voltage supplied by the car’s electrical system to the high voltage required to
fire the spark plugs.