1999 DODGE RAM gas type

EARLY FUEL EVAPORATION (EFE)
The EFE valve is actuated by either a vacuum actuator or a
bimetal spring (heat-riser type). The EFE valve is closed when engine
is cold. The closed valve restricts exhaust gas flow from the exhaust
manifold. This forces part of the exhaust gas to flow up through a
passage below the carburetor. As the exhaust gas quickly warms the
intake mixture, distribution is improved. This results in better cold
engine driveability, shorter choke periods and lower emissions.
Ensure EFE valve in exhaust manifold is not frozen or rusted
in a fixed position. On vacuum-actuated EFE system, check EFE thermal
vacuum valve and check valve(s). Also check for proper vacuum hose
routing. See Fig. 15.
Fig. 15: Typical Vacuum-Actuated EFE System
Courtesy of General Motors Corp.
EMISSION MAINTENANCE REMINDER LIGHT (EMR) (IF EQUIPPED)

is to be serviced, slowly loosen inlet side of fuel fill tube fitting
at check valve. It is normal for approximately 25 psi of residual
natural gas pressure to flow from loosened fitting. At this point, all
fuel tubes are purged of natural gas between fuel cylinders and
engine. It is now okay to open fuel system.
WARNING: Fuel cylinders still contain high-pressure fuel.
Compressed Natural Gas Fuel Cylinder Purging (5.2L)
1) Open manual shutoff valve. Open only fuel control valve(s)\
(counterclockwise) on fuel cylinder(s) to be serviced. Close all oth\
er
control valve(s) (clockwise) on fuel cylinder(s) not being service\
d.
2) Start and operate engine until it runs out of fuel.
Attempt 3 more engine starts. At this point, all fuel tubes and opened
cylinders are purged of natural gas between fuel cylinders and engine.
It is now okay to open fuel system.
WARNING: Fuel cylinders not being serviced still contain high-pressure
fuel.
FUEL LINE DISCONNECT FITTINGS
Removal & Installation (Tab Type Fitting)
1) Release fuel pressure. See FUEL PRESSURE RELEASE.
Disconnect negative battery cable. Ensure area around fuel line and
disconnect fitting is clean. Place shop towel around fuel line.
2) On 2-tab connectors, squeeze retainer tabs together and
pull fuel tube/quick-connect fitting assembly off of fuel tube nipple.
On single-tab connectors, use screwdriver to pry up pull tab. See
Fig. 1 . Raise pull tab until it separates from quick-connect fitting.
Discard old pull tab. Disconnect quick-connect fitting from fuel line.
CAUTION: DO NOT install a quick-connect fitting without retainer being
either in fuel tube or already in quick-connect fitting.
After installing fuel line in disconnect fitting, pull on
fuel line and disconnect fitting to ensure fuel line is
locked in place.
3) To install, coat fuel tube nipple with clean 30W engine
oil. Insert quick-connect fitting into fuel tube until stop on fuel
tube rests against back of quick-connect fitting.
4) On single-tab connectors, obtain NEW pull tab. Push tab
down until it locks into quick-connect fitting. On 2-tab connectors,
firmly pull on fuel tube and fitting to ensure retainer and quick-
connect fitting are locked.
Removal & Installation (Retainer Type Fitting)
1) Release fuel pressure. See FUEL PRESSURE RELEASE.
Disconnect negative battery cable. Ensure area around fuel line and
disconnect fitting is clean. Place shop towel around fuel line.
2) Pull backward on disconnect fitting while depressing
plastic ring into disconnect fitting. See Fig. 2. Separate fuel line
from disconnect fitting.
NOTE: Plastic retainer ring must be pressed squarely into fitting
body. If retainer is cocked during removal, it may be
difficult to disconnect fitting. Use open-end wrench on
shoulder of plastic retainer to ease disconnection.
3) To install, ensure plastic ring is in outward position
(away from disconnect fitting). If plastic ring is in inward position
(toward disconnect fitting), disconnect fitting must be replaced.
4) Lubricate end of fuel line with 30W engine oil. Insert

NOTE: Always refer to appropriate engine overhaul article in the
ENGINES section for complete overhaul procedures and
specifications for the vehicle being repaired.
REMOVAL
Remove intake and exhaust manifolds and valve cover. Cylinder
head and camshaft carrier bolts (if equipped), should be removed only
when the engine is cold. On many aluminum cylinder heads, removal
while hot will cause cylinder head warpage. Mark rocker arm or
overhead cam components for location.
Remove rocker arm components or overhead cam components.
Components must be installed in original location. Individual design
rocker arms may utilize shafts, ball-type pedestal mounts or no rocker
arms. For all design types, wire components together and identify
according to the corresponding valve. Remove cylinder head bolts.
Note length and location. Some applications require cylinder head
bolts be removed in proper sequence to prevent cylinder head damage.
See Fig. 1 . Remove cylinder head.
Fig. 1: Typical Cylinder Head Tightening or Loosening Sequence
This Graphic For General Information Only
INSTALLATION
Ensure all surfaces and head bolts are clean. Check that head
bolt holes of cylinder block are clean and dry to prevent block damage
when bolts are tightened. Clean threads with tap to ensure accurate
bolt torque.
Install head gasket on cylinder block. Some manufacturer's
may recommend sealant be applied to head gasket prior to installation.
Note that all holes are aligned. Some gasket applications may be
marked so certain area faces upward. Install cylinder head using care
not to damage head gasket. Ensure cylinder head is fully seated on
cylinder block.
Some applications require head bolts be coated with sealant
prior to installation. This is done if head bolts are exposed to water
passages. Some applications require head bolts be coated with light
coat of engine oil.

Reasons to Suggest Repair or Replacement
1 - Part is close to the end of its useful life (just above
discard specifications, or weak; failure likely to occur
soon, etc.)
2 - To address a customer need, convenience, or request (to
stiffen ride, enhance performance, eliminate noise,
etc.)
3 - To comply with maintenance recommended by the vehicle's
Original Equipment Manufacturer (OEM)
4 - Technician's recommendation based on substantial and
informed experience
NOTE: Suggested services are always optional. When presenting
suggested repairs to the customer, you must present the
facts, allowing the customer to draw their own conclusions
and make an informed decision about how to proceed.
ENGINE ASSEMBLIES
SERVICE PROCEDURES REQUIRED AND SUGGESTED FOR PROPER VEHICLE
OPERATION
CYLINDER HEAD ASSEMBLIES
NOTE: A Cylinder Head Assembly is a cylinder head fitted with
valves, associated springs, retainers, and on overhead
camshaft cylinder heads (OHC), camshaft, camshaft
bearings, lash adjusters, tappets and rockers.
CYLINDER HEAD ASSEMBLY INSPECTION









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Condition Code Procedure
Adjustable valve lash is
out of specification ... B ................. Require repair.
Internal component failure
(any component) ........ A ........... ( 1) Require repair or
replacement of cylinder
head assembly.
( 1) - It is Required that all other failure related components
be inspected for cause and condition. Additional components
or assemblies may be Suggested for repair or replacement,
such as a water pump on a short block (reason code 4,
technician's recommendation based on substantial and
informed experience).
Example:
If there is a failed head gasket with an external coolant
leak, in addition to Requiring replacement of the head
gasket, inspection of the following for cause and condition
is Required: Block, Cooling System, Cylinder Head. It may
be Suggested that additional inspections be performed, such
as the other head gasket on a V-type engine.









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LONG BLOCK ASSEMBLIES
NOTE: A Long Block Assembly is a short block assembly together
with a cylinder head assembly and all those components
fitted within the rocker or cam cover, and timing cover

(the whole presented as an assembly). A rebuilt or new
oil pump, or kit shall be supplied or fitted as
appropriate.
LONG BLOCK ASSEMBLY INSPECTION









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Condition Code Procedure
Internal component failure
(any component) ........ A ........... (1) Require repair or
replacement of the long
block assembly.
( 1) - It is Required that all other failure related components
be inspected for cause and condition. Additional components
or assemblies may be Suggested for repair or replacement
such as a water pump on a short block (reason code 4,
technician's recommendation based on substantial and
informed experience).
Example:
If there is a failed head gasket with an external coolant
leak, in addition to Requiring replacement of the head
gasket, inspection of the following for cause and
condition is Required: Block, Cooling System, Cylinder
Head. It may be Suggested that additional inspections be
performed, such as the other head gasket on a V-type
engine.









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SHORT BLOCK ASSEMBLIES
NOTE: A Short Block Assembly is a cylinder block and all those
components contained within the limits of the block deck
or decks, the pan rail, the block rear face and the
timing cover (where fitted), including the crankshaft.
SHORT BLOCK ASSEMBLY INSPECTION









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Condition Code Procedure
Any internal component
failure ................ A ........... ( 1) Require repair or
replacement of the short
block assembly.
( 1) - It is Required that all other failure related components
be inspected for cause and condition. Additional
components or assemblies may be Suggested for repair or
replacement, such as a water pump on a short block
(reason code 4, technician's recommendation based on
substantial and informed experience).
Example:
If there is a failed head gasket with an external coolant
leak, in addition to Requiring replacement of the head
gasket, inspection of the following for cause and condition
is Required: Block, Cooling System, Cylinder Head. It may
be Suggested that additional inspections be performed,
such as the other head gasket on a V-type engine.









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Inoperative ............. B ........... (3) Require repair or
replacement. Further
inspection required.
Leaking ................. A .. Require repair or replacement.
Missing ................. C ............ Require replacement.
Resistance out of
specification .......... B .. Require repair or replacement.
Restricted, affecting
performance ............ A .. Require repair or replacement.
Terminal broken ......... A .. Require repair or replacement.
Terminal burned, affecting
performance ............ A ........... ( 1) Require repair or
replacement.
Terminal burned, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal corroded,
affecting performance .. A .. Require repair or replacement.
Terminal corroded, not
affecting performance .. 2 .. Suggest repair or replacement.
Terminal loose, affecting
performance ............ B .. Require repair or replacement.
Terminal loose, not
affecting performance .. 1 .. Suggest repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
Wire lead conductors
exposed ................ B .. Require repair or replacement.
Wire lead corroded ...... A .. Require repair or replacement.
Wire lead open .......... A .. Require repair or replacement.
Wire lead shorted ....... A .. Require repair or replacement.
( 1) - Determine cause and correct prior to repair or
replacement of part.
( 2) - Determine source of contamination, such as engine coolant,
fuel, metal particles, or water. Require repair or
replacement.
( 3) - Inoperative includes intermittent operation or out of
OEM specification. Some components may be serviceable;
check for accepted cleaning procedure.









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EXHAUST GAS RECIRCULATION DEVICES
EXHAUST GAS RECIRCULATION DEVICE INSPECTION








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Condition Code Procedure
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware
threads damaged ........ A ... Require repair or replacement
of hardware.
Attaching hardware
threads stripped
(threads missing) ...... A ... Require repair or replacement
of hardware.
Connector broken ........ A .. Require repair or replacement.
Connector (Weatherpack
type) leaking .......... A .. Require repair or replacement.
Connector melted ........ A ........... ( 1) Require repair or
replacement.

Condition Code Procedure
Application incorrect ... B ........... Require replacement.
Fails to maintain proper
pressure ............... A ........... Require replacement.
Gaskets missing ......... C ........... Require replacement.
Leaking ................. A ........... Require replacement.
Missing ................. C ........... Require replacement.
Plugged (vacuum and
pressure relief) ....... A ........... Require replacement.
Seals missing ........... C ........... Require replacement.









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GASKETS
GASKET INSPECTION








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Condition Code Procedure
Leaking ................. A ........... ( 1) Require repair or
replacement.
( 1) - Require inspection of mating and sealing surface and
repair or replace as necessary.









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GROMMETS (VALVE COVER)
GROMMET (VALVE COVER) INSPECTION








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Condition Code Procedure
Leaking ................. 2 ........... ( 1) Suggest repair or
replacement.
( 1) - Require inspection of mating and sealing surface and
repair or replace as necessary.









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HARMONIC DAMPERS
HARMONIC DAMPER INSPECTION








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Condition Code Procedure
Application incorrect ... B ........... Require replacement.
Attaching hardware
broken ................. A .. Require repair or replacement
of hardware.
Attaching hardware
missing ................ C ......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A .. Require repair or replacement
of hardware.
Cracked ................. A ........... Require replacement.
Dented (fluid
type only) ............. A ........... Require replacement.
Keyway distorted ........ A . Require repair or replacement.
Leaking (Fluid damper
only) .................. A ........... Require replacement.
Loose ................... A ........... Require replacement.
Noisy ................... A ........... Require replacement.

loose .................. A ... Require repair or replacement
of injection tube or
replacement of catalytic
converter.
Air injection tube
restricted ............. A ... Require repair or replacement
of injection tube or
replacement of catalytic
converter.
Air injection tube
threads damaged ........ A ... Require repair or replacement
of injection tube or
replacement of catalytic
converter.
Air injection tube
threads stripped
(threads missing) ...... A ... Require repair or replacement
of injection tube or
replacement of catalytic
converter.
Body cracked ............ B .. Require repair or replacement.
Converter empty ......... A .. Require repair or replacement.
Converter fill plug
missing ................ C .. Require repair or replacement.
Converter missing ....... C ............ Require replacement.
Exhaust gases leaking ... A .. Require repair or replacement.
Flanges leaking ......... A ... Require repair or replacement
of flanges.
Inlet pipes cracked ..... B .. Require repair or replacement.
Internal rattle (except
pellet-type) ........... 2 .......... (1) Further inspection
required.
Mounting brackets that
are part of converter
broken ................. A .. Require repair or replacement.
Obvious overheating ..... .. ......... ( 2) Require testing of
converter.
Outlet pipes cracked .... B .. Require repair or replacement.
Pieces of catalyst
material found
downstream ............. 1 ............ Suggest replacement.
Plugged ................. A ........ ( 3) Require replacement.
Testing has determined
that existing converter
has been lead-poisoned,
contaminated, or failed
testing ................ A .. Require repair or replacement.
( 1) - If the converter is breaking up, suggest converter
replacement. If an object has fallen into the converter,
remove the object.
( 2) - Overheating is caused by something other than the
converter. Further diagnosis is required to determine
the cause of the overheating.
( 3) - Determine cause and correct to ensure that new converter
will not become plugged.









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EXHAUST AND TAIL PIPES
NOTE: For pipes with resonators, also see MUFFLERS AND RESONATORS.
EXHAUST AND TAIL PIPE INSPECTION