1993 DODGE TRUCK fuel cap

•

ENGINES
9 - S
ENGINE
DIAGNOSIS
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine tune-ups. These malfunctions may be classified as either per­
formance (e.g., engine idles rough and stalls) or me­ chanical (e.g., a strange noise). Refer to the Service Diagnosis—Performance chart
and the Service Diagnosis—Mechanical chart for pos­
sible causes and corrections of malfunctions. Refer to
Group 14, Fuel System for the fuel system diagnosis.

SERWIGE DIAGNOSIS (GASOLINE ENGINES)
-
PERFORMANCE
CONDITION

POSSIBLE
CAUSES
CORRECTION

ENGINE
WILL
NOT
START
1.
Weak
battery.

2.
Corroded
or
loose
battery
connections.

3.
Faulty
starter.

4.
Moisture
on
ignition wires and distributor
cap.

5.
Faulty
ignition
cables.

6.
Faulty
coil
or
control
unit.

7.
Incorrect
spark
plug
gap.
8.
Incorrect
ignition timing.
9.
Dirt
or
water
in
fuel
system.

10.
Faulty
fuel
pump.
1.
Test
battery
specific
gravity.
Charge
or
replace
as
necessary.

2. Clean
and
tighten
battery
connections.
Apply
a
coat
of light
mineral
grease
to
the terminals.
3. Refer to
Group
8A, Battery/Starter/Charging
System
Diagnostics.

4. Wipe
wires
and
cap
clean
and
dry.
5.
Replace
any
cracked
or
shorted
cables.

6.
Test
and
replace,
if
necessary
(refer
to
Group
8D,
Ignition
System).

7.
Set
gap
(refer
to
Group
8D, Ignition
System).

8. Refer to
Group
8D, Ignition
System.

9. Clean
system
and
replace
fuel
filter.

10. Install new
fuel
pump
(refer
to
Group
14,
Fuel
System).

ENGINE
STALLS
OR

ROUGH
IDLE
1.
Idle
speed
set
too
low.
2.
Idle
mixture
too
lean
or
too
rich.
3. Leak in
intake
manifold.
4. Worn or burned distributor
rotor.

5.
Incorrect
ignition wiring.
6.
Faulty
coil.

7.
EGR
valve leaking.
1.
Refer to
Group
14,
Fuel
System.

2. Refer to
Group
14,
Fuel
System.

3.
Inspect
intake
manifold
gasket
and
vacuum
hoses.
Replace,
if
necessary
(refer
to
Group
11,
Exhaust
System
&
Intake

Manifold).

4.
Install new distributor
rotor.

5. Install
correct
wiring.
6.
Test
and
replace,
if
necessary
(refer
to
Group
8D,
Ignition
System).

7.
Test
and
replace,
if
necessary
(refer
to
Group
25,
Emissions
Control
System).

J9309-105

•

ENGINES
9 - 11 SERVICE DIAGNOSIS (DIESEL ENGINE) - PERFORMANCE (CONT.)

CONDITION
POSSIBLE
CAUSES
CORRECTION

LOW
POWER
(Cont'd)
SJow
throttle
response, leaking
air
fuel
control
tube
or
improperly
operating
control

in the pump. Tighten the fittings. Replace the pump if the controls are not
functioning.
Incorrect
external
injection

pump
timing. Verify
that
injection pump timing marks are aligned (see Group
14, Fuel System).
Inadequate intake air flow. Inspect/replace air cleaner element. Look for other restrictions.

High
pressure
fuel
leak. Inspect/correct leaks in the high pressure lines, fittings
injector

sealing
washers or delivery valve
seals.

Inadequate
fuel
supply.
Check
the flow through the
filter
to locate the source of the
restriction.

High
fuel
temperature. Verify
that
fuel
heater is off during warm weather. Check for a
restricted
fuel
drain manifold. Repair/replace as needed.

Poor
quality
fuel
or
fuel

contaminated
with
gasoline. Verify by operating from a temporary tank
with
good
fuel.

Check
for presence of
gasoline.
Replace
fuel/water
separator

filter.

Air
leak between the turbo- charger and the intake manifold. Check/correct leaks in the air crossover tube,
hoses,
gaskets,

and
around mounting capscrews or through holes in the manifold
cover.

Exhaust
leak at the manifold
or turbocharger. Check/correct leaks in the manifold or turbocharger
gaskets.

If manifold is cracked, replace manifold.
Improperly operating turbo-
charger. Inspect/replace turbocharger.
Valve clearance incorrect.
Check/adjust
valves.
Injection pump improperly
operating. Check/time pump
(refer
to Group 14, Fuel System).

Worn
or improperly operating injectors. Check/replace injectors.
Improperly operating injection

pump.
Replace
injection pump.

Excessive
exhaust restriction. Check/correct the restriction in the exhaust system.

EXCESSIVE
EXHAUST

SMOKE
Engine
running too cold
(white

smoke).
Refer to troubleshooting logic for coolant
temperature
below
normal
(refer
to Group 7,
Cooling
System).
Inspect intake
manifold heater/KSB valve for proper operation.
Inadequate intake air.
Inspect/change
air cleaner. Look for other restriction.

Air
leak between turbocharger

and
intake manifold. Check/correct leaks in the air crossover tube,
hoses,
gaskets,

mounting capscrews or through holes in the manifold cover.

Exhaust
leak at the manifold
or turbocharger. Check/correct leaks in the manifold or turbocharger
gaskets.

If cracked replace manifold.
Improperly operating
turbocharger. Inspect/replace turbocharger.
J9209-57

9
- 12
ENGINES

•
CONDITION

POSSIBLE
CAUSES
CORRECTION

EXCESSIVE
EXHAUST

SMOKE
(Cont'd)
More
than
one
sealing washer
under an injector.
Check
and remove
extra
washer.
Improperly operating injectors.
Check
and replace inoperative injectors.
Improperly operating or over-
fueled injection pump.
Replace
injection pump.

Piston
rings
not sealing
(blue smoke). Perform blow-by check. Correct as required.

ENGINE
WILL
NOT

SHUT-OFF
Fuel shutoff valve inoperative.

Engine
running on fumes drawn into the air intake.
Stop
the engine mechanically
with
lever on the
fuel
pump.

Check/replace
sealing washer, piston and
spring.

Check
the air intake ducts for the source of the fumes.
WARNING:
In
ease
of engine runaway due to flammable
fumes

from gasoline spills or turbocharger oil leaks
being
sucked
into the
engine,
shut off engine ignition switch first then use a CO* or dry
chemical type
fire
extinguisher
and direct the
spray
under
the
front
bumper to
remove
oxygen
supply. The engine air
intake
is on the

passenger
side
behind the bumper. The
fire
extinguisher
must
bo
directed at this location for emergency shutdown conditions.

COOLANT
TEMPERA­

TURE
ABOVE
NORMAL
Low
coolant level.
(a) Check coolant level. Add coolant, if necessary.
(b) Locate and correct the source of the coolant leak. Refer to
troubleshooting
logic for coolant
loss.

Incorrect/improperly operating

pressure
cap.
Replace
cap
with
the correct rating for the
system.

High
lube oil level.
Check/drain
oil to correct level.

Loose
drive belt on water

pump/fan.
Check/replace
belt or belt tensioner.
Inadequate air flow to the radiator. Check/repair radiator core, fan shroud and fan clutch as
required.

Radiator
fins
plugged.
Blow
debris from fins.

Collapsed
radiator
hose.
Replace
the
hose.

Improperly operating tempera­

ture
sensor/gauge.
Verify
that
the
gauge
and temperature
sensor
are accurate.

Replace
gauge/sensor,
if bad.
Improperly operating, incorrect

or
no thermostat.
Check
and replace the thermostat.

Air
in the cooling
system.
(a) Make sure the
fill
rate
is not being exceeded and the correct
vented thermostat is installed.
(b) Check for loose hose
clamps.
Tighten if
loose.

(c) If aeration continued, check for a
compression
leak through the head gasket.
Inoperative water pump.
Check
and replace the water pump.
incorrect injection pump timing. Verify pump timing marks are aligned. Check/time the injector

pump
(refer
to Group 7,
Cooling
System).
J9209-56
SERVICE DIAGNOSIS (DIESEL ENGINE) - PERFORMANCE (CONT.)

•

3.9L ENGINE
9 - 17
3.9L
ENGINE SERVICE PROCEDURES
INDEX

page

Camshaft
31

Crankshaft
38

Crankshaft Main Bearings
39

Crankshaft Rear
Oil
Seals
. 40

Cylinder Block
41
Cylinder Head Cover
. , 21

Cylinder Heads
. 22
Distributor
33

Engine
Assembly .........................
20

Engine
Front Mounts
17

Engine
Rear Mount
18

Front Crankshaft
Oil
Seal Replacement ........
31

GENERAL INFORMATION
The 3.9 Liter (238 CID) six-cylinder engine is a
V-Type, lightweight, single cam, overhead valve en­ gine with hydraulic roller tappets (Fig. 1).

Engine
Type
90° V-6 OHV

Bore
and Stroke 99.3
x
84.0 mm (3.91 x3.31
in.)

Displacement 3.9L (238 cu.
in.)

Compression
Ratio
9.1:1

Torque 305 N-m (225
ft.
lbs.)
@
3,200
rpm
Firing Order.... 1-6-5-4-3-2

Lubrication
Pressure
Feed-Full Flow
Filtration

Engine
Oil
Capacity 3.8L (4.0 Qts)
with Filter

Cooling
System
Liquid Cooled-Forced
Circulation

Cooling Capacity 14.3L
(15.1
Qts)

Cylinder Block Cast Iron
Crankshaft Nodular Iron
Cylinder Head
Cast
Iron
Combustion Chambers "Fast
Burn"
Design
Camshaft Nodular
Cast
Iron

Pistons
Aluminum Alloy
w/Strut

Connecting
Rods
Forged Steel

J9309-29

Fig.
1
Engine
Description
This engine is designed for unleaded fuel. Engine lubrication system consists of a rotor type
oil pump and a full flow oil filter.
The cylinders are numbered from front to rear; 1,

3,
5 on the left bank and 2, 4, 6 on the right bank.
The firing order is
1-6-5-4-3-2
(Fig. 2).
The engine serial number is stamped into a ma­
chined pad located on the left, front corner of the cyl­
inder block. When component part replacement is
necessary, use the engine type and serial number for
reference (Fig. 3).
page

General
Information
17
Hydraulic Tappets
27

Oil
Pan 34

Oil Pump
34

Piston
/
Connecting
Rod
Assembly
36
Rocker
Arms
21

Specifications—3.9L Engine
43

Timing Chain Cover
29

Valve Stem Seal
/
Spring Replacement ........
27

Valve Timing
28

Valves
/
Valve Springs
25
Vibration
Damper
29
J9309-26
Fig.
2 Firing Order i M 3.9L T xxxx
XXXXXXXX

X
=
Last Digit
of
Model Year
M
=
Plant -
M
Mound
Road

S
Sabillo
T Trenton
K
Toluca

3.9L
=
Engine Displacement
T
=
Usage
-
T Truck

XXXX
=
Month/Day

XXXXXXXX
- Serial Code -
Last
8
Digits of
VIN
No.

J9209-72

Fig.
3
Engine
identification
Number

ENGINE FRONT MOUNTS

REMOVAL (1) Disconnect the negative cable from the battery.

TRANSFER

CASE

INSULATOR

MOUNTING PLATE

NUT(B
RAIL

ASSEMBLY
SPACER

UPPER

INSULATOR

NUT®
LOWER

INSULATOR

J9109-242
Fig.
9 Rear
Engine
Support—4WD
with
Manual

Transmission
(8) If necessary, remove the transmission support
spacer (automatic transmission) from the extension
assembly (Fig. 8).
(9) If necessary, remove the engine rear support
plate (automatic transmission) from the transfer case (Fig. 8).

INSTALLATION-4WD
(1) If removed, position the engine rear support
plate (automatic transmission) to the transfer case (Fig. 8). Install the bolts and tighten to 41 N-m (30
ft. lbs.) torque.
(2) If removed, position the transmission support
spacer (automatic transmission) to the extension as­
sembly (Fig. 8). Install the bolts and tighten to 68 N-m (50 ft. lbs.) torque.
(3) Install insulator mounting plate, mounting

bolts,
spacers, washers and upper/lower insulators to
the rail assembly (Figs. 8 and 9). Tighten the mount­
ing nuts to 204 N*m (150 ft. lbs.) torque.
(4) AUTOMATIC TRANSMISSION-Align the
engine rear support plate and the transmission sup­
port spacer to the insulator mounting plate (Fig. 8). Lower the engine and transmission onto the insula­
tor mounting plate and install the bolts. Tighten the transmission support spacer nuts to 204 N-m (150 ft. lbs.) torque. Tighten the engine rear support plate
bolts to 41 N-m (30 ft. lbs.) torque.
(5) MANUAL TRANSMISSION—Align the
transfer case to the insulator mounting plate and lower the engine and transmission. Install the bolts and tighten the nuts (Fig. 9 - nut A) to 204 N-m (150 ft. lbs.) torque. Install the bolts and tighten the nuts
(Fig. 9 - nut B) to 41 N-m (30 ft. lbs.) torque. (6) Install the skid plate.
(7) Lower the vehicle.

ENGINE
ASSEMBLY

REMOVAL (1) Scribe hood hinge outlines on hood. Remove the
hood.
(2) Remove the battery. (3) Drain cooling system (refer to Group 7, Cooling
System for the proper procedure).
(4) Remove the air cleaner. (5) Disconnect the radiator and heater hoses. Re­
move radiator (refer to Group 7, Cooling System).
(6) Set fan shroud aside. (7) Remove the vacuum lines. (8) Remove the distributor cap and wiring.
(9) Disconnect the accelerator linkage.
(10) Remove MPI throttle body. (11) Disconnect the fuel lines. (12) Disconnect the starter wires.
(13) Disconnect the oil pressure wire. (14) Discharge the air conditioning system, if
equipped (refer to Group 24, Heating and Air Condi­
tioning for service procedures). (15) Disconnect the air conditioning hoses.
(16) Disconnect the power steering hoses, if
equipped. (17) Remove starter motor (refer to Group 8B, Bat­
tery/Starter/Generator Service). (18) Remove the generator (refer to Group 8B, Bat­
tery/Starter/Generator Service).
(19) Raise and support the vehicle on a hoist.
(20) Disconnect exhaust pipe at manifold.
(21) AUTOMATIC TRANSMISSION: (a) Support transmission. This will assure that
the torque converter will remain in proper position in the transmission housing. (b) Remove bell housing bolts and inspection
plate.
(c) Attach a C-clamp on front bottom of trans­
mission torque converter housing to prevent torque
converter from falling out.
(d) Remove torque converter drive plate bolts
from torque converter drive plate. Mark converter and drive plate to aid in assembly.
(22) MANUAL TRANSMISSION: (a) Support transmission.
(b) Disconnect clutch release mechanism and re­
move transmission to clutch housing bolts.

CAUTION:
DO NOT
lift
the engine by the intake
manifold.

(23) Install an engine lifting fixture.
(24) Remove engine front mount bolts.

•
3.9L
ENGINE
9 - 21 (25) Lower the vehicle.
(26) On automatic transmission vehicles, discon­
nect the engine from the torque converter drive
plate. On manual transmission vehicles, move engine forward until drive pinion shaft clears the clutch

disc.
Remove engine from engine compartment. (27) Install engine assembly on engine repair
stand.
INSTALLATION (1) Remove engine from the repair stand and posi­
tion in the engine compartment.
(2) Install engine support fixture.
(3) Raise and support the vehicle on a hoist.

(4)
AUTOMATIC TRANSMISSION: (a) Position the torque converter and drive plate.
Install torque converter drive plate bolts. Tighten
the bolts to 31 Nnn (270 in. lbs.) torque.
(b) Install the engine front mounts.
(c) Install bell housing bolts. Tighten the bolts to
41 N-m (30 ft. lbs.) torque.
(d) Remove C-clamp.
(e) Install the inspection plate.
(5) MANUAL TRANSMISSION: (a) Position the drive pinion shaft to the clutch

disc.
(b) Connect the clutch release mechanism and
install the transmission to clutch bolts. Tighten the
bolts to 68 N-m (50 ft. lbs.) torque.
(c) Install the engine front mounts.
(6) Remove transmission support.
(7) Install exhaust pipe to manifold.
(8) Lower the vehicle.
(9) Remove engine lifting fixture.
(10) Install the generator (refer to Group 8B, Bat­
tery/Starter/Generator Service). (11) Install starter motor (refer to Group 8B, Bat­
tery/Starter/Generator Service). (12) Connect power steering hoses, if equipped.
(13) Connect air conditioning hoses.
(14) Evacuate and charge the air conditioning sys­
tem, if equipped (refer to Group 24, Heater and Air Conditioning for service procedures). (15) Using a new gasket, install MPI throttle body.
Tighten the throttle body bolts to 23 N-m (200 in. lbs.) torque. (16) Connect the accelerator linkage.
(17) Connect the starter wires. (18) Connect the oil pressure wire.
(19) Install the distributor cap and wiring.
(20) Connect the vacuum lines.
(21) Connect the fuel lines.
(22) Install the radiator (refer to Group 7, Cooling
System). Connect the radiator hoses and heater

hoses.

(23) Install fan shroud in position. (24) Fill cooling system (refer to Group 7, Cooling
System for the proper procedures). (25) Install the air cleaner.
(26) Install the battery.
(27) Warm engine and adjust.
(28) Install hood and line up with the scribe
marks. (29) Road test vehicle.

CYLINDER
HEAD COVER
A steel backed silicon gasket is used with the cyl­
inder head cover (Fig. 1). This gasket can be used again.

CYLINDER HEAD COVER GASKET

J9209-104

Fig.
1 Cylinder Head
Cover
Gasket

REMOVAL (1) Disconnect the negative cable from the battery.
(2) Disconnect closed ventilation system and evap­
oration control system from cylinder head cover. (3) Remove cylinder head cover and gasket. The
gasket may be used again.
CLEANING Clean cylinder head cover gasket surface. Clean head rail, if necessary.
INSPECTION Inspect cover for distortion and straighten, if nec­
essary. Check the gasket for use in "head cover installation.
If damaged, use a new gasket.
INSTALLATION (1) The cylinder head cover gasket can be used
again. Install the gasket onto the head rail.
(2) Position the cylinder head cover onto the gas­
ket. Tighten the bolts to 11 N-m (95 in. lbs.) torque. (3) Install closed crankcase ventilation system and
evaporation control system.
(4) Connect the negative cable to the battery.

ROCKER
ARMS

REMOVAL (1) Disconnect spark plug wires by pulling on the
boot straight out in line with plug.
(2) Remove cylinder head cover and gasket.

(3) Remove the rocker arm bolts and pivots (Fig.

2).
Place them on a bench in the same order as re­
moved.
(4) Remove the push rods and place them on a
bench in the same order as removed.

ROCKER
ARMS

J9209-66
Fig.
2
Rocker Arms
INSTALLATION
(1) Rotate the crankshaft until the "V6" mark
lines up with the TDC mark on the timing chain
case cover. This mark is located 147° ATDC from the
No.l firing position.

CAUTION:
DO NOT
rotate
or
crank
the
engine dur­
ing
or
immediately
after
rocker
arm
installation.
Al­

low
the
hydraulic roller tappets adequate time
to
bleed down (about
5
minutes).

(2) Install the push rods in the same order as re­
moved.
(3) Install rocker arm and pivot assemblies in the
same order as removed. Tighten the rocker arm bolts
to 28 N*m (21 ft. lbs.) torque.
(4) Install cylinder head cover.
(5) Connect spark plug wires.

CYLINDER
HEADS
The alloy cast iron cylinder heads (Fig. 3) are held
in place by 8 bolts. The spark plugs are located in
the peak of the wedge between the valves.

REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Drain cooling system (refer to Group 7, Cooling
System for the proper procedures). (3) Remove the heat shields (Fig. 4).
SPARK SPARK
INTAKE

PLUGS
PLUG VALVE
EXHAUST INTAKE EXHAUST VALVE VALVES VALVES
J9309-35

Fig.
3 Cylinder Head
Assembly Fig.
4
Exhaust
Manifold Heat
Shields

(4) Remove the intake manifold-to-generator
bracket support rod. Remove the generator.
(5) Remove closed crankcase ventilation system.
(6) Disconnect the evaporation control system.
(7) Remove the air cleaner.
(8) Disconnect the fuel lines.
(9) Disconnect accelerator linkage and if so
equipped, the speed control and transmission kick-
down cables. (10) Remove the return spring.
(11) Remove distributor cap and wires.
(12) Disconnect the coil wires.
(13) Disconnect heat indicator sending unit wire.
(14) Disconnect heater hoses and bypass hose.
(15) Remove cylinder head covers and gaskets.
(16) Remove intake manifold and throttle body as
an assembly. Discard the flange side gaskets and the
front and rear cross-over gaskets.
(17) Remove exhaust manifolds.
(18) Remove rocker arm assemblies and push rods.
Identify to ensure installation in original locations.

(9) Install the flange gaskets. Be sure that the ver­
tical port alignment tab is resting on the deck face of
the block. Also the horizontal alignment tabs must
be in position with the mating cylinder head gasket
tabs (Fig. 8). The words MANIFOLD SIDE should be
visible on the center of each flange gasket.
FLANGE GASKET


INTAKE
AAANIFOLD
CYLINDER
HEAD GASKET
J9209-101

Fig.
8 Intake Manifold Flange
Gasket
Alignment

(10) Carefully lower intake manifold into position
on the cylinder block and cylinder heads. Use the alignment dowels in the cross-over gaskets to posi­
tion the intake manifold. After intake manifold is in
place, inspect to make sure seals are in place.
(11) The following torque sequence duplicates the
expected results of the automated assembly system
(Fig. 9).
• Step
1-Tighten
bolts 1 and 2 to 8 N-m (72 in. lbs.)
torque. Tighten in alternating steps 1.4 N-m (12 in. lbs.) torque at a time.
• Step 2—Tighten bolts 3 through 12, in sequence,
to 8 N-m (72 in. lbs.) torque.
• Step 3—Check that all bolts are tighten to 8 N-m (72 in. lbs.) torque.
• Step 4—Tighten all bolts, in sequence, to 16 N-m (12 ft. lbs.) torque.
• Step 5—Check that all bolts are tighten to 16 N-m (12 ft. lbs.) torque. (12) Install exhaust manifolds. Tighten the bolts
and nuts to 34 N-m (25 ft. lbs.) torque.
FRONT OF ENGINE

J9209-59

Fig.
9 Intake Manifold
Bolt
Tightening
Sequence
(13) Adjust spark plugs to specifications (refer to
Group 8D, Ignition System). Install the plugs and
tighten to 41 N-m (30 ft. lbs.) torque.
(14) Install coil wires. (15) Connect heat indicator sending unit wire.
(16) Connect the heater hoses and bypass hose.
(17) Install distributor cap and wires.
(18) Hook up the return spring.
(19) Connect the accelerator linkage and if so
equipped, the speed control and transmission kick-
down cables.
(20) Install the fuel lines.
(21) Install the generator and drive belt. Tighten
generator mounting bolt to 41 N-m (30 ft. lbs.)
torque. Tighten the adjusting strap bolt to 23 N-m (200 in. lbs.) torque. Refer to Group 7, Cooling Sys­
tem for adjusting the belt tension. (22) Install the intake manifold-to-generator
bracket support rod. Tighten the bolts. (23) Place the cylinder head cover gaskets in posi­
tion and install cylinder head covers. Tighten the
bolts to 11 N-m (95 in. lbs.) torque.
(24) Install closed crankcase ventilation system.
(25) Connect the evaporation control system.
(26) Install the air cleaner.
(27) Install the heat shields. Tighten the bolts to
41 N-m (30 ft. lbs.) torque. (28) Fill cooling system (refer to Group 7, Cooling
System for proper procedure). (29) Connect the negative cable to the battery.