VALVES
DESCRIPTION SPECIFICATION
Metric Standard
Face Angle-
Intake- 45-45.5É
Face Angle-
Exhaust- 45-45.5É
Head Diameter-
Intake47.87-48.13
mm1.88-1.89 in.
Head Diameter-
Exhaust35.37-35.63
mm1.39-1.40 in.
Valve Lift (Zero
Lash)-Intake
and Exhaust-
3.3L9.80 mm 0.385 in.
Valve Lift (Zero
Lash)-Intake
and Exhaust-
3.8L11.0 mm 0.433 in.
Valve Length-
Intake125.84-126.6
mm4.95-4.98 in.
Valve Length-
Exhaust127.20-127.96 5.00-5.04 in.
Valve Stem to
Tip Height
(valve tip to
spring seat
washer)-Intake48.1-49.7 mm 1.89-1.95 in.
Valve Stem to
Tip Height
(valve tip to
spring seat
washer)-
Exhaust48.53-50.09
mm1.91-1.97 in.
VALVE SEAT
DESCRIPTION SPECIFICATION
Metric Standard
Angle - 44.5-45É
Run Out
(Service Limits)0.0762 mm 0.003 in.
Width-Intake
and Exhaust1.50-2.00 mm 0.057-0.078 in.
VALVE GUIDE
DESCRIPTION SPECIFICATION
Metric Standard
Guide Bore
Diameter (Std.)6.975-7.00 mm 0.274-0.275 in.
VALVE MARGIN
DESCRIPTION SPECIFICATION
Metric Standard
Intake 0.825-0.973
mm0.032-0.038 in.
Exhaust 1.565-1.713
mm0.061-0.067 in.
VALVE STEM DIAMETER
DESCRIPTION SPECIFICATION
Metric Standard
Intake
(Standard)6.935-6.953
mm0.2718-0.2725
in.
Exhaust
(Standard)6.906-6.924
mm0.2718-0.2725
in.
VALVE STEM TO GUIDE CLEARANCE
DESCRIPTION SPECIFICATION
Metric Standard
Intake 0.025-0.065
mm0.001-0.0025 in.
Exhaust 0.059-0.094
mm0.002-0.0037 in.
Max Allowable-
Intake (Rocking
Method)0.247 mm 0.010 in.
Max Allowable-
Exhaust
(Rocking
Method)0.414 mm 0.016 in.
PUSH RODS
DESCRIPTION SPECIFICATION
Metric Standard
Length 135.438 mm 5.33 in.
9 - 96 ENGINE 3.3/3.8LRS
ENGINE 3.3/3.8L (Continued)
CYLINDER HEAD COVER -
LEFT
REMOVAL
(1) Disconnect spark plug wires from spark plugs.
(2) Disconnect crankcase vent hose from cylinder
head cover.
(3) Remove cylinder head cover bolts.
(4) Remove cylinder head cover and gasket.
INSTALLATION
(1) Clean cylinder head and cover mating surfaces.
Inspect cylinder head cover surface for flatness.
Replace gasket as necessary.
(2) Assemble gasket to cylinder cover by inserting
the fasteners through each bolt hole on cover and
gasket (Fig. 25).
(3) Install the cylinder head cover and bolts (Fig.
26).
(4) Tighten cylinder head cover bolts to 12 N´m
(105 in. lbs.) (Fig. 26).
(5) Connect crankcase vent hose.
(6) Connect spark plug wires to spark plugs.
INTAKE/EXHAUST VALVES &
SEATS
DESCRIPTION
The valves have chrome plated valve stems with
four-bead lock grooves. The valve stem seals are
made of Viton rubber.
OPERATION
The two valves per cylinder are opened using
hydraulic lifters, push rods, and rocker arms.
STANDARD PROCEDURE - REFACING VALVES
AND VALVE SEATS
The intake and exhaust valves and seats are
machined to specific angles (Fig. 27).
VALVES
(1) Inspect the remaining margin after the valves
are refaced (Fig. 28). (Refer to 9 - ENGINE - SPEC-
IFICATIONS)
VALVE SEATS
CAUTION: Remove metal from valve seat only. Do
not remove material from cylinder head (Fig. 29).
(1) When refacing valve seats, it is important that
the correct size valve guide pilot be used for reseat-
ing stones. A true and complete surface must be
obtained.(2) Measure the concentricity of valve seat using
dial indicator (Fig. 30). Total runout should not
exceed 0.051 mm (0.002 in.) total indicator reading.
(3) Inspect the valve seat using Prussian blue to
determine where the valve contacts the seat. To do
this, coat valve seatLIGHTLYwith Prussian blue
then set valve in place. Rotate the valve with light
pressure. If the blue is transferred to the center of
valve face, contact is satisfactory. If the blue is trans-
ferred to top edge of valve face, lower valve seat with
a 15 degree stone. If the blue is transferred to the
bottom edge of valve face raise valve seat with a 65
degrees stone.
Fig. 27 VALVE FACE AND SEAT
1 - VALVE FACE WIDTH
2 - VALVE FACE ANGLE
3 - SEAT ANGLE
4 - SEAT CONTACT AREA
Fig. 28 Valve Margin
1 - VALVE FACE
2 - VALVE MARGIN
RSENGINE 3.3/3.8L9 - 107
NOTE: Valve seats which are worn or burned can
be reworked, provided that correct angle and seat
width are maintained. Otherwise cylinder head must
be replaced.
(4) When seat is properly positioned the width of
intake and exhaust seats should be 1.50±2.00 mm
(0.059±0.078 in.) (Fig. 27).
(5) After grinding the valve seats or faces, install
the valve in cylinder head and check valve installed
height by measuring from valve tip to spring seat
(Fig. 31). Remove valve from cylinder head and grind
valve tip until within specifications. Check valve tip
for scoring. The tip chamfer should be reground (if
necessary) to prevent seal damage when the valve is
installed.(6) Check the valve spring installed height after
refacing the valve and seat (Fig. 31).
If valves and/or seats are reground, measure
the installed height of springs (Fig. 31), make
sure measurements are taken from top of
spring seat to the bottom surface of spring
retainer. If height is greater than specifica-
tions, install a 0.794 mm (0.0312 in.) spacer in
head counterbore to bring spring height back
within specifications.
REMOVAL
(1) With cylinder head removed, compress valve
springs using Valve Spring Compressor Tool
C-3422-D with adapter 8464 (Refer to 9 - ENGINE -
SPECIAL TOOLS).
(2) Remove valve retaining locks.
(3) Slowly release valve spring compressor.
Remove valve spring retainer, valve spring, and valve
stem seal.
(4) Before removing valves,remove any burrs
from valve stem lock grooves to prevent dam-
age to the valve guides.Identify valves to insure
installation in original location.
CLEANING
(1) Clean all valves thoroughly and discard
burned, warped and cracked valves.
INSPECTION
VALVES
(1) Clean and inspect valves thoroughly. Replace
burned, warped and cracked valves.
Fig. 29 Refacing Valve Seats
1 - REFACING STONE MUST NOT CUT INTO CYLINDER HEAD
2-STONE
3 - PILOT
4 - SEAT
Fig. 30 Measurement of Valve Seat Runout
1 - DIAL INDICATOR
Fig. 31 Checking Valve and Spring Installed Height
1 - SPRING RETAINER
2 - VALVE INSTALLED HEIGHT* - 48.1±49.7 mm (1.89±1.95 in.)
3 - CYINDER HEAD SURFACE
4 - SPRING INSTALLED HEIGHT* - 41.1±42.7 mm (1.61±1.68 in.)
*(MEASURED FROM TOP OF SPRING SEAT)
9 - 108 ENGINE 3.3/3.8LRS
INTAKE/EXHAUST VALVES & SEATS (Continued)
CONNECTING ROD BEARINGS
STANDARD PROCEDURE - MEASURING
CONNECTING ROD BEARING CLEARANCE
The bearing caps are not interchangeable and
should be marked at removal to ensure correct
assembly. The bearing shells must be installed with
the tangs inserted into the machined grooves in the
rods and caps. Install cap with the tangs on the same
side as the rod. Fit all rods on one bank until com-
plete. Connecting rod bearings are available in the
standard size and the following undersizes: 0.025
mm (0.001 in.) and 0.250 mm (0.010 in.).
CAUTION: Install the bearings in pairs. Do not use a
new bearing half with an old bearing half. Do not
file the rods or bearing caps.
Measure connecting rod journal for taper and out-
of-round. (Refer to 9 - ENGINE/ENGINE BLOCK/
CRANKSHAFT - INSPECTION)The connecting rod bearing clearances can be
determined by use of Plastigage or the equivalent.
The following is the recommended procedure for the
use of Plastigage:
(1) Rotate the crankshaft until the connecting rod
to be checked is at the bottom of its stroke.
(2) Remove oil film from surface to be checked.
Plastigage is soluble in oil.
(3) Place a piece of Plastigage across the entire
width of the bearing shell in the bearing cap approx-
imately 6.35 mm (1/4 in.) off center and away from
the oil hole. In addition, suspect areas can be
checked by placing Plastigage in that area.
(4) Assemble the rod cap with Plastigage in place.
Tighten the rod cap to the specified torque.Do not
rotate the crankshaft while assembling the cap
or the Plastigage may be smeared, giving inac-
curate results.
(5) Remove the bearing cap and compare the
width of the flattened Plastigage with the scale pro-
vided on the package (Fig. 61). Locate the band clos-
est to the same width. This band indicates the
Fig. 60 Piston and Connecting Rod Positioning (Front View of Engine)
1 - MAJOR THRUST SIDE OF PISTON2 - OIL SQUIRT HOLE
RSENGINE 3.3/3.8L9 - 123
PISTON & CONNECTING ROD (Continued)
Upper and lower number 2 bearing halves are
flanged to carry the crankshaft thrust loads and are
NOT interchangeable with any other bearing halves
in the engine (Fig. 69). All bearing cap bolts removed
during service procedures are to be cleaned and
lubricated with engine oil before installation. Bearing
shells are available in standard and the following
undersizes: 0.025 mm (0.001 in.) and 0.254 mm
(0.010 in). Never install an undersize bearing that
will reduce clearance below specifications.
CRANKSHAFT BEARING OIL CLEARANCE
Inspect the crankshaft bearing journals. (Refer to 9
- ENGINE/ENGINE BLOCK/CRANKSHAFT -
INSPECTION)
Engine crankshaft bearing clearances can be deter-
mined by use of Plastigage or the equivalent. The fol-
lowing is the recommended procedures for the use ofPlastigage with the engine in the vehicle or engine
on a repair stand.
PLASTIGAGE METHODÐENGINE IN-VEHICLE
NOTE: The total clearance of the main bearings can
only be determined with the engine in the vehicle
by removing the weight of the crankshaft. This can
be accomplished by either of two following meth-
ods:
(1) Preferred method:
a. Shim the bearings adjacent to the bearing to be
checked in order to remove the clearance between
upper bearing shell and the crankshaft. This can be
accomplished by placing a minimum of 0.254 mm
(0.010 in.) shim (e. g. cardboard, matchbook cover,
etc.) between the bearing shell and the bearing cap
on the adjacent bearings and tightening bolts to
14±20 N´m (10±15 ft. lbs.).
²When checking #1 main bearing shim #2 main
bearing.
²When checking #2 main bearing shim #1 & #3
main bearing.
²When checking #3 main bearing shim #2 & #4
main bearing.
²When checking #4 main bearing shim #3 main
bearing.
NOTE: Remove all shims before reassembling
engine.
(2) Alternative Method:
a. Support the weight of the crankshaft with a
jack under the counterweight adjacent to the bearing
being checked.
(3) Remove oil film from surface to be checked.
Plastigage is soluble in oil.
(4) Place a piece of Plastigage across the entire
width of the bearing shell in the cap approximately
6.35 mm (1/4 in.) off center and away from the oil
holes (Fig. 70). (In addition, suspected areas can be
checked by placing the Plastigage in the suspected
area). Torque the bearing cap bolts of the bearing
being checked to the proper specifications.
(5) Remove the bearing cap and compare the width
of the flattened Plastigage (Fig. 71) with the scale
provided on the package. Locate the band closest to
the same width. This band shows the amount of
clearance in thousandths. Differences in readings
between the ends indicate the amount of taper
present. Record all readings taken. (Refer to 9 -
ENGINE - SPECIFICATIONS)Plastigage gener-
ally is accompanied by two scales. One scale is
in inches, the other is a metric scale.
Fig. 68 Main Bearing Cap Identification
Fig. 69 Main Bearing Identification
1 - OIL GROOVES
2 - OIL HOLES
3 - UPPER BEARINGS
4 - LOWER BEARINGS
9 - 126 ENGINE 3.3/3.8LRS
CRANKSHAFT MAIN BEARINGS (Continued)
NOTE: Plastigage is available in a variety of clear-
ance ranges. Use the most appropriate range for
the specifications you are checking.
PLASTIGAGE METHODÐENGINE OUT-OF-VEHICLE
(1) With engine in the inverted position (crank-
shaft up) and mounted on a repair stand, remove
main journal cap.
(2) Remove oil from journal and bearing shell.
(3) Cut Plastigage to same length as width of the
bearing and place it in parallel with the journal axis
(Fig. 70).
(4) Carefully install the main bearing cap and
tighten the bolts to specified torque.
CAUTION: Do not rotate crankshaft or the Plasti-
gage will be smeared.
(5) Carefully remove the bearing cap and measure
the width of the Plastigage at the widest part using
the scale on the Plastigage package (Fig. 71). Refer
to Engine Specifications for proper clearances (Refer
to 9 - ENGINE - SPECIFICATIONS). If the clearance
exceeds the specified limits, replace the main bear-
ing(s) with the appropriate size, and if necessary,
have the crankshaft machined to next undersize.
REMOVAL - CRANKSHAFT MAIN BEARINGS
(1) Remove the oil pan. (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL)(2) Identify main bearing caps before removal.
(3) Remove bearing caps one at a time. Remove
upper half of bearing by inserting Special Main Bear-
ing Tool C-3059 (Fig. 72) into the oil hole of crank-
shaft.
(4) Slowly rotate crankshaft clockwise, forcing out
upper half of bearing shell.
INSTALLATION - CRANKSHAFT MAIN
BEARINGS
NOTE: One main bearing should be selectively fit-
ted while all other main bearing caps are properly
tightened.
(1) For main bearing fitting procedure, (Refer to 9
- ENGINE/ENGINE BLOCK/CRANKSHAFT MAIN
BEARINGS - STANDARD PROCEDURE)
(2) Start bearing in place, and insert Main Bearing
Tool C-3059 into oil hole of crankshaft (Fig. 72).
(3) Slowly rotate crankshaft counterclockwise slid-
ing the bearing into position. Remove Special Main
Bearing Tool C-3059.
(4) Inspect main cap bolts for stretching (Fig. 73).
Replace bolts that are stretched.
NOTE: The main cap bolts should be examined
before reuse. Bolt stretch can be checked by hold-
ing a scale or straight edge against the threads. If
all the threads do not contact the scale the bolt
must be replaced (Fig. 73).
(5) Install each main cap and tighten bolts finger
tight.
Fig. 70 Plastigage Placed in Lower
1 - PLASTIGAGE
Fig. 71 Clearance Measurement
Fig. 72 Upper Main Bearing Removing/Installing
With Special Tool C-3059
1 - SPECIAL TOOL C-3059
2 - BEARING
3 - SPECIAL TOOL C-3059
4 - BEARING
RSENGINE 3.3/3.8L9 - 127
CRANKSHAFT MAIN BEARINGS (Continued)
FUEL INJECTION
OPERATION
OPERATION - INJECTION SYSTEM
All engines used in this section have a sequential
Multi-Port Electronic Fuel Injection system. The MPI
system is computer regulated and provides precise
air/fuel ratios for all driving conditions. The Power-
train Control Module (PCM) operates the fuel injec-
tion system.
The PCM regulates:
²Ignition timing
²Air/fuel ratio
²Emission control devices
²Cooling fan
²Charging system
²Idle speed
²Vehicle speed control
Various sensors provide the inputs necessary for
the PCM to correctly operate these systems. In addi-
tion to the sensors, various switches also provide
inputs to the PCM.
The PCM can adapt its programming to meet
changing operating conditions.
Fuel is injected into the intake port above the
intake valve in precise metered amounts through
electrically operated injectors. The PCM fires the
injectors in a specific sequence. Under most operat-
ing conditions, the PCM maintains an air fuel ratio
of 14.7 parts air to 1 part fuel by constantly adjust-
ing injector pulse width. Injector pulse width is the
length of time the injector is open.
The PCM adjusts injector pulse width by opening
and closing the ground path to the injector. Engine
RPM (speed) and manifold absolute pressure (air
density) are theprimaryinputs that determine
injector pulse width.
OPERATION - MODES OF OPERATION
As input signals to the PCM change, the PCM
adjusts its response to output devices. For example,
the PCM must calculate a different injector pulse
width and ignition timing for idle than it does for
Wide Open Throttle (WOT). There are several differ-
ent modes of operation that determine how the PCM
responds to the various input signals.
There are two different areas of operation, OPEN
LOOP and CLOSED LOOP.
During OPEN LOOP modes the PCM receives
input signals and responds according to preset PCM
programming. Inputs from the upstream and down-
stream heated oxygen sensors are not monitored dur-
ing OPEN LOOP modes, except for heated oxygensensor diagnostics (they are checked for shorted con-
ditions at all times).
During CLOSED LOOP modes the PCM monitors
the inputs from the upstream and downstream
heated oxygen sensors. The upstream heated oxygen
sensor input tells the PCM if the calculated injector
pulse width resulted in the ideal air-fuel ratio of 14.7
to one. By monitoring the exhaust oxygen content
through the upstream heated oxygen sensor, the
PCM can fine tune injector pulse width. Fine tuning
injector pulse width allows the PCM to achieve opti-
mum fuel economy combined with low emissions.
For the PCM to enter CLOSED LOOP operation,
the following must occur:
(1) Engine coolant temperature must be over 35ÉF.
²If the coolant is over 35ÉF the PCM will wait 38
seconds.
²If the coolant is over 50ÉF the PCM will wait 15
seconds.
²If the coolant is over 167ÉF the PCM will wait 3
seconds.
(2) For other temperatures the PCM will interpo-
late the correct waiting time.
(3) O2 sensor must read either greater than 0.745
volts or less than 0.29 volt.
(4) The multi-port fuel injection systems has the
following modes of operation:
²Ignition switch ON (Zero RPM)
²Engine start-up
²Engine warm-up
²Cruise
²Idle
²Acceleration
²Deceleration
²Wide Open Throttle
²Ignition switch OFF
(5) The engine start-up (crank), engine warm-up,
deceleration with fuel shutoff and wide open throttle
modes are OPEN LOOP modes. Under most operat-
ing conditions, the acceleration, deceleration (with
A/C on), idle and cruise modes,with the engine at
operating temperatureare CLOSED LOOP modes.
IGNITION SWITCH ON (ZERO RPM) MODE
When the ignition switch activates the fuel injec-
tion system, the following actions occur:
²The PCM monitors the engine coolant tempera-
ture sensor and throttle position sensor input. The
PCM determines basic fuel injector pulse width from
this input.
²The PCM determines atmospheric air pressure
from the MAP sensor input to modify injector pulse
width.
When the key is in the ON position and the engine
is not running (zero rpm), the Auto Shutdown (ASD)
and fuel pump relays de-energize after approximately
14 - 22 FUEL INJECTIONRS
1 second. Therefore, battery voltage is not supplied to
the fuel pump, ignition coil, fuel injectors and heated
oxygen sensors.
ENGINE START-UP MODE
This is an OPEN LOOP mode. If the vehicle is in
park or neutral (automatic transaxles) or the clutch
pedal is depressed (manual transaxles) the ignition
switch energizes the starter relay when the engine is
not running. The following actions occur when the
starter motor is engaged.
²If the PCM receives the camshaft position sensor
and crankshaft position sensor signals, it energizes
the Auto Shutdown (ASD) relay and fuel pump relay.
If the PCM does not receive both signals within
approximately one second, it will not energize the
ASD relay and fuel pump relay. The ASD and fuel
pump relays supply battery voltage to the fuel pump,
fuel injectors, ignition coil, (EGR solenoid and PCV
heater if equipped) and heated oxygen sensors.
²The PCM energizes the injectors (on the 69É
degree falling edge) for a calculated pulse width until
it determines crankshaft position from the camshaft
position sensor and crankshaft position sensor sig-
nals. The PCM determines crankshaft position within
1 engine revolution.
²After determining crankshaft position, the PCM
begins energizing the injectors in sequence. It adjusts
injector pulse width and controls injector synchroni-
zation by turning the individual ground paths to the
injectors On and Off.
²When the engine idles within 64 RPM of its
target RPM, the PCM compares current MAP sensor
value with the atmospheric pressure value received
during the Ignition Switch On (zero RPM) mode.
Once the ASD and fuel pump relays have been
energized, the PCM determines injector pulse width
based on the following:
²MAP
²Engine RPM
²Battery voltage
²Engine coolant temperature
²Inlet/Intake air temperature (IAT)
²Throttle position
²The number of engine revolutions since cranking
was initiated
During Start-up the PCM maintains ignition tim-
ing at 9É BTDC.
ENGINE WARM-UP MODE
This is an OPEN LOOP mode. The following inputs
are received by the PCM:
²Manifold Absolute Pressure (MAP)
²Crankshaft position (engine speed)
²Engine coolant temperature
²Inlet/Intake air temperature (IAT)²Camshaft position
²Knock sensor
²Throttle position
²A/C switch status
²Battery voltage
²Vehicle speed
²Speed control
²O2 sensors
The PCM adjusts injector pulse width and controls
injector synchronization by turning the individual
ground paths to the injectors On and Off.
The PCM adjusts ignition timing and engine idle
speed. Engine idle speed is adjusted through the idle
air control motor.
CRUISE OR IDLE MODE
When the engine is at operating temperature this
is a CLOSED LOOP mode. During cruising or idle
the following inputs are received by the PCM:
²Manifold absolute pressure
²Crankshaft position (engine speed)
²Inlet/Intake air temperature
²Engine coolant temperature
²Camshaft position
²Knock sensor
²Throttle position
²Exhaust gas oxygen content (O2 sensors)
²A/C switch status
²Battery voltage
²Vehicle speed
The PCM adjusts injector pulse width and controls
injector synchronization by turning the individual
ground paths to the injectors On and Off.
The PCM adjusts engine idle speed and ignition
timing. The PCM adjusts the air/fuel ratio according
to the oxygen content in the exhaust gas (measured
by the upstream and downstream heated oxygen sen-
sor).
The PCM monitors for engine misfire. During
active misfire and depending on the severity, the
PCM either continuously illuminates or flashes the
malfunction indicator lamp (Check Engine light on
instrument panel). Also, the PCM stores an engine
misfire DTC in memory, if 2nd trip with fault.
The PCM performs several diagnostic routines.
They include:
²Oxygen sensor monitor
²Downstream heated oxygen sensor diagnostics
during open loop operation (except for shorted)
²Fuel system monitor
²EGR monitor (if equipped)
²Purge system monitor
²Catalyst efficiency monitor
²All inputs monitored for proper voltage range,
rationality.
RSFUEL INJECTION14-23
FUEL INJECTION (Continued)