fuel CHEVROLET DYNASTY 1993 Service Manual

length of the spring to be tested is 33.34mm (1-5/16
inches). Turn table of Tool C-647 until surface is in line
with the 33.34mm (1-5/16 inch) mark on the threaded
stud and the zero mark on the front. Place spring over
stud on the table and lift compressing lever to set tone
device. Pull on torque wrench until ping is heard. Take
reading on torque wrench at this instant. Multiply this
reading by two. This will give the spring load at test
length. Fractional measurements are indicated on the
table for finer adjustments. Refer to specifications to
obtain specified height and allowable tensions. Discard
the springs that do not meet specifications.
VALVE INSTALLATION
(1) Coat valve stems with clean engine oil and insert
them in cylinder head. (2) Check valve tip to spring seat dimension A after
grinding the valve seats or faces. Grind valve tip to give
49.541 to 51.271 mm (1.950 to 2.018 inch.) over spring
seat when installed in the head (Fig. 17). Check valve
tip for scoring, if necessary, the tip chamfer should be
reground to prevent seal damage when the valve is
installed. (3) Install new cup seals on all valve stems and over
valve guides (Fig. 24). Install valve springs and valve
retainers.
(4) Compress valve springs with Valve Spring Com-
pressor Tool C-3422-B, with adapter 6412 install locks
and release tool. If valves and/or seats are re-
ground, measure the installed height of springs
dimension B, make sure measurements is taken
from top of spring seat to the bottom surface of
spring retainer. If height is greater than 1-19/32
inches, (40.6mm), install a 1/32 inch (.794mm)
spacer in head counterbore to bring spring
height back to normal 1-17/32 to 1-19/32 inch (39.1
to 40.6mm) .
REPLACE VALVE STEM SEALS OR VALVE
SPRINGS, CYLINDER HEAD NOT REMOVED
(1) Perform fuel system pressure release procedure
before attempting any repairs (2) Disconnect negative battery cable. (3) Remove Air Cleaner Cover and hose assembly.
(4) Remove Intake Manifold; Refer to
Intake/Exhaust Manifold 3.3/3.8L Engine Group 11
Exhaust System and Intake Manifolds of this manual
for removal procedure. (5) Remove cylinder head covers and spark plugs.
(6) Remove connector wire from ignition coils.
(7) Using suitable socket and flex handle at crank-
shaft pulley retaining screw, turn engine so the num-
ber 1 piston is at Top Dead Center on the compression
stroke. (8) Remove rocker arms with rocker shaft and in-
stall a dummy shaft. The rocker arms should not be
disturbed and left on shaft. (9) With air hose attached to spark plug adapter
installed in number 1 spark plug hole, apply 90 to 100
psi air pressure (620.5 to 689 kPa). This is to hold
valves into place while servicing components. (10) Using Tool C-4682 or Equivalent compress
valve spring and remove retainer valve locks and valve
spring. (11) The intake valve stem seals should be pushed
firmly and squarely over the valve guide using the
valve stem as guide. Do Not Forceseal against top of
guide. When installing the valve retainer locks, com-
press the spring only enoughto install the locks.
CAUTION:Do not pinch seal between retainer and top
of valve guide .
(12) Follow the same procedure on the remaining 5
cylinders using the firing sequence 1-2-3-4-5-6. Make
sure piston in cylinder is at TDC on the valve
spring that is being covered. (13) Remove spark plug adapter tool .
(14) Remove dummy shaft and install rocker shaft
assembly and tighten screws to 28 N Im (250 in. lbs.).
Fig. 24 Checking Valve Installed Height
Fig. 25 Installing Valve, Cup Seal, Spring and Re-
tainer
Ä 3.3/3.8L ENGINE 9 - 107

CAUTION: Avoid application of rust prevention
compounds or undercoating materials to exhaust
system floor pan heat shields on cars if equipped.
Light overspray near the edges is permitted. Appli-
cation of coating will greatly reduce the efficiency
of the heat shields resulting in excessive floor pan
temperatures and objectionable fumes.
The combustion reaction caused by the catalyst re-
leases additional heat in the exhaust system. Caus-
ing temperature increases in the area of the reactor
under severe operating conditions. Such conditions
can exist when the engine misfires or otherwise does
not operate at peak efficiency. Do notremove spark
plug wires from plugs or by any other means short
out cylinders if exhaust system is equipped with cat-
alytic converter. Failure of the catalytic converter
can occur due to temperature increases caused by un-
burned fuel passing through the converter. The use of the catalysts also involves some non-au-
tomotive problems. Unleaded gasoline must be used
to avoid poisoning the catalyst core. Do not allow en- gine to operate above 1200 RPM in neutral for ex-
tended periods over 5 minutes. This condition may
result in excessive exhaust system/floor pan temper-
atures because of no air movement under the vehicle.
EXHAUST GAS RECIRCULATION (EGR) SYSTEM
To assist in the control of oxides of nitrogen (NOx)
in engine exhaust, some engines are equipped with
an exhaust gas recirculation system. The use of ex-
haust gas to dilute incoming air/fuel mixtures lowers
peak flame temperatures during combustion, thus
limiting the formation of NOx. Exhaust gases are taken from openings in the ex-
haust gas crossover passage in the intake manifold.
REFER TO SECTION 25 EMISSION SYSTEMS
FOR A COMPLETE DESCRIPTION, DIAGNOSIS
AND SERVICE PROCEDURES ON THE EXHAUST
GAS RECIRCULATION SYSTEM AND COMPO-
NENTS.
EXHAUST SYSTEM DIAGNOSIS
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 3

SERVICE PROCEDURES INDEX
page page
Exhaust Pipes, Mufflers and Tailpipes .......... 4
Intake and Exhaust Manifolds ServiceÐTBI Engine.6Intake and Exhaust ManifoldsÐFlexible Fuel Engine.7
Intake and Exhaust ManifoldsÐTBI Engine ...... 5
Intake/Exhaust Manifold ServiceÐ3.0L Engine . . . 13
Intake/Exhaust Manifold ServiceÐ3.3/3.8L Engines.19
Intake/Exhaust Manifolds and Turbocharger ServiceÐTurbo III Engine .................. 9
Intake/Exhaust Manifolds ServiceÐFlexible Fuel Engines ............................... 7
EXHAUST PIPES, MUFFLERS AND TAILPIPES
REMOVAL
(1) Raise vehicle on hoist and apply penetrating oil
to clamp bolts and nuts of component being removed. (2) Tail pipes are integral with the muffler (Fig. 5).
Remove clamp at slip joint. Separate at slip joint. (3) Remove clamps and supports (Figs. 6, 7, 8, and 9)
from exhaust system to permit alignment of parts
during assembly. (4) When removing tailpipe, raise rear of vehicle to
relieve body weight from rear springs to provide clear-
ance between pipe and rear axle parts. (5) Clean ends of pipes and/or muffler to assure
mating of all parts. Discard broken or worn insulators,
rusted clamps, supports and attaching parts. When replacement is required on any compo-
nent of the exhaust system, it is most important
that original equipment parts (or their equiva-
lent) be used;
² To insure proper alignment with other parts in the
system.
² Provide acceptable exhaust noise levels and does not
change exhaust system back pressure that could affect
emissions and performance.
INSTALLATION
(1) Assemble ball joint connection pipes, supports
and clamps loosely to permit alignment of all parts.
Fig. 6 Insulator Tail Pipe and Muffler Support
Fig. 7 Underfloor Converter or Extension Pipe SupportÐ2 Places
Fig. 5 Tail Pipe with MufflerÐTypical
11 - 4 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä

for diagnostic and service procedures on the air control
valve and temperature sensor located in the air
cleaner.
INTAKE AND EXHAUST MANIFOLDS SERVICEÐTBI
ENGINE
Intake and exhaust manifolds use a one piece gasket.
Service procedures requiring removal and installation
( of either ) must include both manifolds.
FUEL SYSTEM PRESSURE RELEASE PROCE- DURE
The Fuel System is under a constant pressure
of at least 265 kPa (39 psi). Before servicing the
fuel pump, fuel lines, fuel filter, throttle body or
fuel injector, the fuel system pressure must be
released. (a) Loosen fuel filler cap to release fuel tank pres-
sure. (b) Disconnect injector wiring harness from engine
harness. (c) Connect a jumper wire to ground terminal
Number 1 of the injector harness (Fig. 2) to engine
ground. (d) Connect a jumper wire to the positive terminal
Number 2 of the injector harness (Fig. 2) and touch
the battery positive post for no longer than 5 seconds.
This releases system pressure. (e) Remove jumper wires.
(f) Continue fuel system service.
REMOVAL
(1) Perform fuel system pressure release procedure
before attempting any repairs. (2) Disconnect negative battery cable. Drain cool-
ing system. Refer to Cooling System, Group 7 for pro-
cedure. (3) Remove air cleaner and disconnect all vacuum
lines, electrical wiring and fuel lines from throttle
body. (4) Remove throttle linkage.
(5) Loosen power steering pump and remove belt.
(6) Remove power brake vacuum hose from intake
manifold. (7) Disconnect EGR tube from intake manifold and
remove water hoses from water crossover. (8) Raise vehicle and remove exhaust pipe from
manifold. (9) Remove power steering pump assembly and set
aside. (10) Remove intake manifold retaining screws
(Fig. 3). (11) Lower vehicle and remove intake manifold.
(12) Remove exhaust manifold retaining nuts (Fig.
3). (13) Remove exhaust manifold.
Fig. 2 Injector Harness Connector
Fig. 3 Intake and Exhaust Manifold Attaching PointsÐ2.2/2.5L Engines
Fig. 1 Air HeaterÐTBI Engine
11 - 6 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä

CLEANING AND INSPECTION
(1) Discard gaskets and clean all gasket surfaces
on both manifolds and on cylinder head. (2) Test gasket surfaces of manifolds for flatness
with a straight edge. Surfaces must be flat within
0.15mm per 300mm (.006 in. per foot) of manifold
length. (3) Inspect manifolds for cracks and distortion.
INSTALLATION
(1) Install a new intake and exhaust manifold gas-
ket. Coat steel gasket lightly with Gasket Sealer on
manifold side. Do notcoat composition gasket with
(any) sealer. (2) Set exhaust manifold in place. Tighten retain-
ing nuts starting at center and progressing outward
in both directions to 23 N Im (200 in. lbs.) torque. Re-
peat this procedure until all nuts are at specified
torque. (3) Set intake manifold in place.
(4) Raise vehicle and tighten retaining screws
starting at center and progressing outward in both
directions to 23 N Im (200 in. lbs.) torque (Fig. 3). Re-
peat this procedure until all screws are at specified
torque. (5) Reverse removal procedures 1-9 for installation.
(6) With the DRBII Scan Tool use ASD Fuel Sys-
tem Test to pressurize system to check for leaks.
CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) relay will remain ener-
gized for 7 minutes or until the ignition switch is
turned to the OFF position, or Stop All Test is se-
lected.
INTAKE AND EXHAUST MANIFOLDSÐFLEXIBLE
FUEL ENGINE
INTAKE MANIFOLD
The manifold is die-cast aluminum with upper ple-
num and 4 tubes lower runners. These attach to the
cylinder head, with each runner leading directly to a
cylinder. The manifold is also machined for fuel rail attach-
ment and injector installation. The throttle body is
installed on the upper plenum of the manifold.
EXHAUST MANIFOLD
All high strength iron casting that intermesh with
the intake manifold. For standard engines a four
branch design collects and directs exhaust gases to
the conical (articulated joint connection) outlet.
INTAKE/EXHAUST MANIFOLDS
SERVICEÐFLEXIBLE FUEL ENGINES
Intake and exhaust manifolds use a one piece gas-
ket. Service procedures requiring removal and instal-
lation of either must include both manifolds.
SERVICE PRECAUTIONS
Methanol is more toxic than gasoline. Always re-
lease fuel system pressure before servicing fuel sys-
tem components and wear methanol resistant gloves
and eye protection. Avoid breathing methanol vapors or ingesting
methanol. Headaches, dizziness and even uncon-
sciousness could result from breathing these vapors.
Serious injury, blindness and even death could result
from ingesting methanol. Methanol vapors are extremely flammable and can
travel along the ground. Service vehicles in well ven-
tilated areas and avoid ignition sources. Never
smoke while servicing the vehicle. Do not allow methanol to contact skin. Prolonged
contact with methanol can cause dry skin or an al-
lergic skin reaction. Also, prolonged contact could re-
sult in absorption through the skin.
FUEL SYSTEM PRESSURE RELEASE PROCEDURE
WARNING: RELEASE FUEL SYSTEM PRESSURE
BEFORE SERVICING FUEL SYSTEM COMPONENTS.
WEAR METHANOL RESISTANT GLOVES AND EYE
PROTECTION WHILE SERVICING THE FUEL SYS-
TEM.
(a) Disconnect negative cable from battery.
(b) Remove fuel filler cap.
(c) Remove the protective cap from the fuel pres-
sure test port on the fuel rail (Fig. 4).
(d) Place the open end of fuel pressure release
hose, tool number C-4799-1, into an approved gas-
oline container. Connect the other end of hose
C-4799-1 to the fuel pressure test port (Fig. 5).
Fuel pressure will bleed off through the hose into
the gasoline container. Fuel gauge C-4799-A con-
tains hose C-4799-1.
Fig. 4 Fuel Pressure Test Port
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 7

INTAKE MANIFOLD
REMOVAL (1) Perform fuel system pressure release procedure
before attempting any repairs. (2) Disconnect negative battery cable.
(3) Remove air cleaner hose to throttle body (Fig.
6).
(4) Remove accelerator and speed control cables.
(5) Disconnect automatic idle speed (AIS) motor
and throttle position sensor (TPS) wiring connectors
(Fig. 7). (6) Disconnect fuel injectors wiring connector.
(7) Remove supply and return lines from the fuel
tube assembly quick connect at frame rail. Open fuel
tube clip around fuel tubes. WARNING: WRAP SHOP TOWELS AROUND HOSES
TO CATCH ANY FUEL SPILLAGE.
(8) Disconnect fuel pressure regulator vacuum hose
from regulator (Fig. 8). (9) Remove PCV vacuum harness, brake booster,
and vacuum vapor harness from intake manifold
(Fig. 8). (10) Remove 8 intake manifold screws and washer
assemblies and remove intake manifold assembly
(Fig. 9).
Fig. 5 Releasing Fuel Pressure
Fig. 6 Air Cleaner Hose to Throttle Body Assembly
Fig. 7 Throttle Position Sensor and Air Idle Control Motor Electrical Connections
Fig. 8 Electrical and Vacuum Hose Connection
11 - 8 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä

EXHAUST MANIFOLD
REMOVAL (1) Disconnect exhaust pipe from manifold articu-
late joint. (2) Disconnect the heated oxygen sensor electrical
connection. (3) Remove 8 exhaust manifold retaining nuts and
remove exhaust manifold (Fig. 9).
CLEANING AND INSPECTION
(1) Discard gasket and clean all gasket surfaces of
manifolds and cylinder head. (2) Test gasket surfaces for flatness with straight
edge. Surface must be flat within 0.15 mm per 300
mm (.006 in. per foot) of manifold length. (3) Inspect manifolds for cracks or distortion.
EXHAUST MANIFOLD
INSTALLATION
(1) Install new two-sided grafoil or equivalent in-
take/exhaust manifold gasket. DO NOT APPLY
SEALER. (2) Set exhaust manifold in place. Install and
tighten retaining nuts, starting at center and pro-
gressing outward in both directions to 23 N Im (200
in. lbs.) torque. Repeat this procedure until all nuts
are at specified torque.
INTAKE MANIFOLD
INSTALLATION
(1) Position intake manifold, install, and tighten 8
retaining screws starting at center and progressing
outward in both directions to 23 N Im (200 in. lbs.)
torque. Repeat this procedure until all screws are at
specified torque (Fig. 9). (2) Install PCV vacuum harness and vacuum vapor
harness (Fig. 8). (3) Connect vacuum hose from fuel pressure regu-
lator. (4) Connect fuel injector wiring connector (Fig. 8).
(5) Close fuel tube clip around fuel tubes and in-
stall fastener. (6) Lubricate the ends of the chassis fuel tubes
with 30 wt oil. Connect fuel supply and return hoses
to chassis fuel tube assembly. pull back on the quick
connect fitting to ensure complete insertion. (Refer to
Fuel Hoses, Clamps and Quick Connect Fittings in
Group 14 Fuel Systems). (7) Connect automatic idle speed (AIS) motor and
throttle position sensor (TPS) wiring connectors (Fig.
7). (8) Connect accelerator and speed control cables.
Install brake booster vacuum supply hoses. (9) Reconnect negative battery cable.
(10) Install air cleaner hose to throttle body assem-
bly (Fig. 6). (11) With the DRBII Scan Tool use ASD Fuel Sys-
tem Test to pressurize system to check for leaks.
CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) relay will remain ener-
gized for 7 minutes or until the ignition switch is
turned to the OFF position, or Stop All Test is se-
lected.
INTAKE/EXHAUST MANIFOLDS AND
TURBOCHARGER SERVICEÐTURBO III ENGINE
INTAKE MANIFOLD
REMOVAL
(1) Perform fuel system pressure release procedure
before attempting any repairs. (2) Disconnect negative battery cable. Drain cool-
ing system. Refer to Cooling System, Group 7. (3) Remove fresh air duct from air filter housing.
Remove inlet hose from the intercooler (Fig. 1). (4) Remove radiator hose to cylinder head (Fig. 2).
(5) Remove DIS Ignition Coils from intake mani-
fold (Fig. 3). (6) Remove accelerator and speed control cables
(Fig. 4).
Fig. 9 Intake and Exhaust Manifolds Attaching Points
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 9

(7) Disconnect Intercooler to throttle body outlet
hose. Disconnect vacuum hoses from throttle body
and remove harness (Fig. 5).
(8) Disconnect automatic idle speed (AIS) motor
and throttle position sensor (TPS) wiring connectors
(Fig. 6). (9) Remove PCV Breather/Separator box and vac-
uum harness assembly. Remove brake booster, vac-
uum vapor harness and fuel pressure regulator
harness from intake manifold (Fig. 7). (10) Disconnect Fuel Injector Wiring Connector
(Fig. 8). Charge Temperature Wiring Connector (Fig.
7). (11) Remove fuel supply and return hose quick
connect at fuel tube assembly (Fig. 9). WARNING: WRAP SHOP TOWELS AROUND HOSES
TO CATCH ANY GASOLINE SPILLAGE
.
(12) Remove 8 intake manifold screws and washer
assemblies and remove intake manifold (Fig. 10).
INSTALLATION
Before installing manifold. Refer to Cleaning and
Inspection of this section to check manifold for dam-
age. (1) Install new intake manifold gasket and intake
manifold onto cylinder head and tighten fasteners to
23 N Im (200 in. lbs.) torque (Fig. 10).
(2) Install PCV Breather/Separator box and vac-
uum harness assembly. Connect brake booster, vac-
uum vapor harness and vacuum hose to fuel pressure
regulator (Fig. 7).
Fig. 1 Air Cleaner and Throttle Body AssemblyÐTurbo III Engine
Fig. 2 Radiator to Cylinder Head Hose
Fig. 3 Distributorless Ignition Coil (DIS) Location
Fig. 4 Accelerator and Speed Control Cables
11 - 10 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä

(3) Inspect quick connect fittings for damage, re-
place if necessary Refer to Fuel System, Group 14 for
procedure. Lube tube with clean 30w engine oil, Con-
nect fuel supply and return hoses to chassis tube as-
sembly. Check connection by pulling on connector to
insure it locked into position (Fig. 9). (4) Connect Fuel Injector (Fig. 8), and Charge
Temperature Sensor wiring connectors (Fig. 7).
INTAKE MANIFOLD
(5) Connect Automatic Idle Speed (AIS) and Throt-
tle Position Sensor (TPS) wiring connectors (Fig. 6). (6) Connect vacuum hoses to throttle body (Fig. 5).
(7) Install intercooler to throttle body hose and
clamp. Torque clamp to 3 N Im (30 in. lbs.) (Fig. 5). (8) Connect accelerator and speed control cables
(Fig. 4). (9) Install DIS ignition coil pack. Tighten fasteners
to 12 N Im (105 in. lbs.) torque (Fig. 3).
(10) Install upper radiator hose and spring clamps
(Fig. 2). Fill cooling system, Refer to Cooling System,
Group 7. (11) Install fresh air duct to air filter housing. In-
stall inlet hose assembly to Intercooler. Tighten
clamp to 3 N Im (30 in. lbs.) torque (Fig. 1).
(12) Connect negative battery cable.
(13) With the DRBII Scan Tool use ASD Fuel Sys-
tem Test to pressurize system to check for leaks.
Fig. 5 Intercooler to Throttle Body Hose
Fig. 6 Automatic Idle Speed (AIS) Motor and
Throttle Position Sensor (TPS) Wiring Connectors
Fig. 7 Intake Manifold Electrical and Vacuum Hose Connections
Fig. 8 Camshaft Sensor and Fuel Injectors WiringConnectors
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 11

CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) relay will remain ener-
gized for 7 minutes or until the ignition switch is
turned to the OFF position, or Stop All Test is se-
lected.
TURBOCHARGER
REMOVAL
The turbocharger is removed from below the vehi-
cle. Cylinder head removal for component accessibil-
ity is not required. (1) Disconnect negative battery cable. Remove Air
Cleaner assembly (Fig. 1). (2) From Above: Remove front engine mount
through bolt and rotate engine (Top) forward away
from cowl. Refer to Engine Removal in Engine,
Group 9. (3) Remove Air Cleaner Support (Fig. 1).
(4) Disconnect Heated Oxygen sensor lead wire
and vacuum lines. (5) Separate coolant return line from water box
and turbocharger housing (Fig. 11). Remove return
line from turbocharger.
(6) Separate oil feed line from turbocharger hous-
ing (Fig. 12). (7) Remove three (two upper and one lower driver's
side) nuts retaining turbocharger to manifold (Fig.
12). (8) From Below: Remove right front wheel and
tire assembly. (9) See Suspension, Group 2, and remove right
driveshaft assembly. Air deflector may need to be removed from cross-
member. (10) Separate oil drain back tube fitting from tur-
bocharger housing and remove fitting and hose (Fig.
13). (11) Remove turbocharger to block support bracket
(Fig. 13). (12) Remove one remaining turbocharger to mani-
fold retaining nut (Fig. 12).
Fig. 11 Coolant Tube Routing
Fig. 12 Turbocharger Attaching Nuts
Fig. 9 Fuel Supply and Return Hose Connections
Fig. 10 Intake Manifold Attaching Bolts.
11 - 12 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä