1973 OPEL GT-R check engine light

6A- 18 1973 OPEL SERVICE MANUAL
pressure. If heavy pressure is required, shell was not
started squarely and will be distorted if force into place.
12. Place lower bearing shell in bearing cap, then
check clearance
with plastic-type gauge, as previ-
ously described.
13. The desired clearance with a new bearing is
.0009” to .0025”. If this clearance cannot be obtained
with a standard size bearing, insert an undersize
bearing and check again
w&h plastic-type gauge
material.
14. When the proper size bearing has been selected,
clean out all plastic gauge material, oil the lower
shell and reinstall bearing cap. Clean the bolt holes
and lube bolts, then torque cap bolts to 72 lb. ft. The
crankshaft should turn freely at flywheel rim; how-
ever, a very slight drag is permissible if an undersize
bearing is used.
15. If the thrust bearing shell is disturbed or replaced
it is necessary to line up the thrust surfaces of the
bearing shell before the cap bolts are tightened. To
do this, move the crankshaft fore and aft the limit of
its travel several times (last movement fore) with the
thrust bearing cap bolts finger tight.
16. After bearing is installed and tested, loosen all
bearing cap bolts
l/2 turn and continue with other
bearings. When bearings have been installed and
tested, tighten all bearing cap bolts to 72 lb. ft.
17. Replace rear bearing oil seals.
18. Install pipe and screen assembly and oil pan.
Installation of Rear Bearing Oil
Seals (Engine in Vehicle)
1. Remove transmission, bell housing and clutch.
Refer to appropriate section for removal procedures.
Figure 6A-28 Removing Rear Main Oil Seal
2. Remove flywheel.
3. Punch a hole into oil seal and screw in a sheet
metal screw and pull out oil seal. See Figure
6A-28.
4. To insure proper sealing, lubricate seal with a
suitable protective grease and install on taper ring
J-22928. Turn seal to ensure lip of seal is not turned
back. See Figure
6A-27.
OIL SEAL’6A-29
Figure
6A-29 Installing Oil Seal on Tool J-22928
5. Place tapered ring with oil seal on crankshaft
flange and move lip of seal
over rear of crankshaft.
Be careful not to tilt seal.
Figure 6A-30 Installing Rear Main Bearing Oil Seal
6. Drive in oil seal using Tool J-22928-2. See Figure
6A-30.
7. Install flywheel, clutch, bell housing and transmis-
.

ENGINE MECHANICAL AND MOUNTS6A- 19
sion. When replacing flywheel use new bolts and
torque to 43 lb.ft.
PISTON, RINGS AND CONNECTING RODS
Removal and Disassembly of Piston
and Rod Assemblies
1. Drain oil.
2. Remove oil pan. 3. Remove cylinder head.
4. Examine the cylinder bores above the ring travel.
If bores are worn so a ridge exists, remove the ridges
with a ridge reamer to avoid damaging rings or
cracking ring lands in pistons during removal.
5. Mark the cylinder number on all pistons, connect-
ing rods and caps. Starting at the front end of the
crankcase, the cylinders are numbered l-2-3-4,
6. Remove cap and bearing shell from number 1
connecting rod.
7. Push the piston and
rod assembly up and out of
top cylinder. Then reinstall cap and bearing shell on
rod.
0
-J-23436-4
J-23436-2+
J-6047
Figure
6A-3 1 Piston Pin Removal Tool Layout - 1 .S
Engine
8. Remove other rod and piston assemblies in the
same manner.
9. Remove compression rings and oil rings.
10. Remove piston pin in following manner:
a. Position base support J-6047 on hydraulic press.
b. Place tool J-23436-2 in base support with large
diameter bore facing upward. See Figure
6A-31.
c. Position piston and rod assembly on tool
J-
23436-2 making certain the pin is aligned on tool.
d. Position tool J-23436-4 in opposite end of piston
pin and press pin out.
Inspection of Cylinder Bores
Inspect cylinder walls for scoring, roughness, or
ridges which indicate excessive wear. Check cylinder
bores for taper and out-of-round with an accurate
cylinder gage at top, middle and bottom
ofbore, both
parallel and at right angles to the centerline of the
engine. The diameter of the cylinder bores at any
point may be measured with an inside micrometer or
by setting the cylinder gauge dial at “0” and measur-
ing across the gauge contact points with outside mi-
crometer while the gauge is at the same “0” setting.
If a cylinder bore is moderately rough or slightly
scored but is not out-of-round or tapered, it is possi-
ble to repair the bore by honing to accept a standard
service piston. If cylinder bore is very rough or deeply scored, it may be necessary to rebore the cyl-
inder to fit an oversize piston in order to insure satis-
factory results.
If a cylinder bore is tapered
.ooO5” or more, or is
out-of-round
.0005” or more, it is advisable to hone
or rebore for the smallest possible oversize piston and
rings.
Visual Inspection of Pistons, Rings, and Pins
Clean carbon from piston surfaces and under side of
piston heads. Clean carbon from ring grooves with a
suitable tool and remove any gum or varnish from
piston skirts with suitable solvent.
Carefully examine pistons for rough or scored bear-
ing surfaces, cracks in skirt, head cracked or broken
ring lands, and chipping or uneven wear which
would cause rings to seat improperly or have exces-
sive clearance in ring grooves. Damaged or faulty
pistons should be replaced.
Fitting Pistons to Cylinders
The pistons are cam ground, which means that the

ENGINE MECHANICAL AND MOUNTS6A- 21
2.. Expand a telescope gage to fit the cylinder bore at
right angles to the piston pin 2-l/2” from top. See
Figure 6A-33.cylinders, the glazed cylinder walls should be slightly
dulled without increasing the bore diameter by
means of the finest grade honing stones.
TELESCOPE GAUGE1
Figure 6A-33 Checking Cylinder Bores
TELESCOPE/GAUGE
MICROMETER
Figure
6A-34 Measuring Telescope Gage3. Measure the piston to be installed. See Figure6A-32. The piston must be measured at right angles
to the piston pin
2-l/2” below the top of piston. The
piston must be between
.C008” and .0012” smaller
than the cylinder bore.
Both block and piston must be at approximately the
same temperature when measurements are made or
expansion errors will occur. A
dif.ference of 10 de-
grees F between parts is sufficient to produce a varia-
tion of .0005”.
Fitting New Piston RingsWhen new piston rings are installed without reboringNew piston rings must be checked for clearance in
piston grooves and for gap in cylinder bores; how-
ever, the flexible oil rings are not checked for gap.
The cylinder bores and piston grooves must be clean,
dry, and free of carbon and burrs.
To check the end gap of compression rings, place the
ring in the cylinder in which it will be used and
square it in the bore by tapping with the lower end
of a piston. Measure the gap with feeler gages.
Piston ring end gap should be
,014” - ,022” (top) and
,014” - ,022” (2nd) and the oil ring end gap should
be
.015” - ,055”.
If gap is less than specified, file the ends of rings
carefully with a smooth tile to obtain proper gap.
Install piston rings as follows:
1. Upper ring is chrome plated and can be installed
either way up. Number two (2) ring has to be in-
stalled with the marking “top” up. Oil ring can be
installed either way
up. See Figure 6A-35.
1. PISTON
2. NO.
I COMPRESSION RING - INSTALLED
WITH EITHER SIDE UP.
3. NO. 2 COMPRESSION RING - INSTALLED
WITH “TOP” MARKING TOWARDS THE TOP.
4. UPPER AND LOWER STEEL BAND RING
-
INSTALLED WITH EITHER SIDE UP.5. INTERMEDIATED RING
- INSTALLED WITH
EITHER SIDE UP.
6A-35
Figure 6A.35 Arrangement of Piston Rings2. Install piston rings so gaps are positioned as shown
in Figure 6A-36.

ENGINE MECHANICAL AND MOUNTS6A- 27
With feeler gauge, check gear backlash. It should be
between
.I?04 in. and .C!OS in. See Figure 6A-46.3. Remove (2) bolts holding pipe and screen assem-
bly to cylinder block. See Figure 6A-47.
FEELERGAUGE6A-46
Figure 6A-46 Measuring Oil Pump Gear Backlash
Checking Oil Pump Relief Valve
For Proper Functioning
1. Unscrew plug and check spring and relief valve
plunger in oil pump cover for dirt particles and free
operation. If required, carefully clean plunger and
seat. Pressure relief plunger sticking as a result of
foreign material or sludge build-up in the oil pump
cover can cause loss of oil pressure.
Removal and Inspection of Oil Pump
Pipe and Screen Assembly
1. Remove oil pan.
2. Clean oil pan. Make sure the gasket surfaces and
pan and block are clean.
Figure 6A-47 Installation of Pipe and Screen
Assembly4. Clean the screen and housing thoroughly in sol-
vent and blow dry with air stream.
Installation of Oil Pump and Screen Assembly
Install by reversing removal procedures, paying par-
ticular attention to the following points.
1. Make sure oil pump pipe flange gasket surface of
block is smooth and free of dirt.
2. Use a new gasket and install assembly.
3. Tighten pan bolts evenly. Do not over-tighten.
Torque to 5 lb. ft.
SPECIFICATIONSBOLT TORQUE SPECIFICATIONS
Use a reliable torque wrench to tighten all parts listed, to insure proper
tightness without straining or distorting parts. These specifications are for
clean and lightly-lubricated threads only; dry or dirty threads produce in-
creased friction which prevents accurate measurement of tightness.

COOLING SYSTEM6B- 33
remove drain plug on right.side of cylinder block. Set
heater temperature control valve at full heat posi-
tion. After the cooling system is drained, and plugs
reinstalled, fill the system with clean water. Run the
engine long enough to open the thermostat for com-
plete circulation through the system, then com-
pletely drain the cooling system before sediment has
a chance to settle.
Conditioning the Cooling System
“Rust Inhibitor and Stop Leak”, or equivalent listed
under Group 8.800 is recommended for use in the
cooling system, particularly when preparing for in-
stallation of anti-freeze solution. This material stops
small seepage leaks, has rust preventive properties
and its soluble oil is effective in eliminating a squeal-
ing noise which sometimes develops at the water
pump seal washer. Instructions for its application are
printed on the conditioner bottle.
It is very important to make certain that the cooling
system is properly prepared before an anti-freeze so-
lution is installed, otherwise loss of solution through
leakage may occur or seepage may result in damage
to the engine. The cooling system should be drained
and flushed as described under Draining and Flush-
ing Cooling System. All joints should be checked for
leakage and corrected, and the conditioner described
above should be added with the anti-freeze solution.
Inspect the water pump, radiator core, heater and
defroster cores, water jacket plugs, and edge of cylin-
der head gaskets for evidence of water leaks. Tighten
all hose clamps in the cooling and heating systems
and replace any deteriorated hoses.
Using and Testing Anti-Freeze
Solutions
Inhibited year around (ethylene glycol type) engine
coolant solution which is formulated to withstand
two full calendar years of normal operation without
draining or adding inhibitors should be used at all
times. Freeze protection should be provided to pro-
tect against corrosion. When adding solution due to
loss of coolant for any reason or in areas where tem-
peratures lower than minus 20 degrees F. may be
encountered, a sufficient amount of any of the sev-
eral brands of year around coolant (Ethylene Glycol
base) compatible to GM Specification 1899-M avail-
able on the market should be used. Water or alcohol
base coolants are not recommended for this vehicle
at any time.
If for any reason water only is used as a coolant in
an emergency, it is extremely important that Buick
Heavy Duty Cooling System Protector and Water
Pump Lubricant or equivalent be added to the cool-
ing system as soon as possible. If any other cooling
System protector is used, be certain it is labeled toindicate that it meets General Motors Specification
GM 1894-M. It should be recognized that this is only
a temporary measure. The manufacture intends that
permanent type coolant solution be used year around
in the cooling system.
The cooling system should be completely drained
and the recommended coolant installed every two (2)years.It is advisable to test the anti-freeze solution at inter-
vals during the winter to make certain that the solu-
tion has not been weakened. Use only hydrometers
which are calibrated to read both the specific gravity
and the temperature, and have a table or other means
of converting the freezing point at various tempera-
tures of solution. Disregarding the temperature of
the solution when making the test may cause an error
as large as 30 degrees F. Care must be exercised to
use the correct float or table for the particular type
of anti-freeze being tested.
Fan Belt Adjustment or Replacement
A tight fan belt will cause rapid wear of the alterna-
tor and water pump bearings. A loose belt will slip
and wear excessively and will cause noise, engine
over-heating, and unsteady alternator output. A fan
belt which is cracked or frayed, or which is worn so
that it bottoms in the pulleys should be replaced. The
fan belt may be replaced by loosening the alternator
brace at alternator, slightly loosening the alternator
mounting bolts and moving alternator inward to pro-
vide maximum slack in the belt.
The alternator must be moved outward to adjust the
fan belt. After the generator brace and mounting
bolts are securely tightened, the fan belt tension
should be 45 lb. using Tensioner J-23600.
WARNING: Zfa
fan blade is bent or damaged in any
way, no attempt should be made to repair and reuse
the damaged part. A bent or damaged fan assembly
should always be replaced with a new
fal. assembly.
It is essential that fan assemblies remain in proper
balance and proper balance cannot be assured once
a fan assembly has been bent or damaged. A fan
assembly that is not in proper balance could fail and
fly apart during subsequent
we creating an ex-
tremely dangerous condition.
Radiator Thermostat Inspection and Test
A sticking radiator thermostat will prevent the cool-
ing system from functioning properly. If the thermo-
stat sticks in the open position, the engine will warm
up very slowly. If the thermostat sticks in the closed
position, the engine will overheat.
The thermostat may be removed for inspection and

6B- 341973 OPEL SERVICE MANUAL
test by partially draining the cooling system and dis-
connecting the water outlet housing from the ther-
mostat housing which is mounted on the right front
side of cylinder head.
The standard thermostat valve should start to open
at 189 degrees F and fully open at approximately 212
degrees F. If thermostat does not operate at specified
temperatures, it should be replaced as it cannot be
repaired.MAJOR REPAIR
WATER PUMP REPAIRSThe water pump bearing outer race is shrunk fit into
the water pump cover. For this reason the cover,
shaft bearing, and hub are not repairable.
Water Pump RemovalOpel radiators do not have a drain plug. Drain radia-
tor by first, loosening radiator cap, then remove
lower hose from lower radiator tank.
1. Drain coolant into a clean container. Remove
radiator and shroud.
2. Remove fan belt.
3. Remove fan blade and pulley on water pump shaft.
4. Disconnect inlet hose and heater hose from water
pump. Remove bolts, pump assembly and gasket
from timing chain cover.
5. Check pump shaft bearing for end play or rough-
ness in operation. If bearings are not in serviceable
condition, the assembly must be replaced.
Water Pump Installation1. Make sure the gasket surfaces on pump and timing
chain covers are clean. Install pump assembly with
new gasket. Bolts must be tightened uniformly.
Torque to 11 lb. ft.
2. Install radiator and shroud. Connect radiator hose
to pump inlet and heater hose to nipple.
3. Install fan pulley and fan blade, tighten attaching
bolts securely. Install belts and adjust for proper
tension.4. Fill cooling system and check
,for leaks at pump
and hose joints.
RADIATOR REMOVAL AND INSTALLATION
RemovalI. Loosen radiator cap, then remove lower radiator
hose and drain radiator coolant into suitable con-
tainer.
2. On vehicles with automatic transmission, unscrew
oil lines from connectors on lower radiator tank and
plug lines. On GT models with automatic transmis-
sion the lines have to be disconnected at the coupling
before removing from the tank. It is essential that no
dirt enters the oil lines. When unscrewing oil lines,
hold connectors on lower radiator tank with pliers to
avoid leakages. Ensure that no dirt enters oil cooler.
3. Remove lower attaching nut and slide radiator
upward and out of engine compartment.
Installation1. Install radiat,or into engine compartment and se-
cure lower attaching nut.
2. On vehicles with automatic transmissions, fasten
oil cooler lines to lower radiator tank. It is essential
that no dirt enters the oil lines. When tightening oil
lines, hold connectors on lower radiator tank with
pliers to avoid leakages. Ensure that no dirt enters oil
cooler. Torque to 1 I-15
lbs.ft.3. Install lower radiator hose and add collected coo-
lant.
All Opels are provided with a radiator initial fill of
an antifreeze solution containing corrosion inhibitor.
The antifreeze has either a glycol or glycerin base
and protects the engine against freezing, down to
minus 22 degrees F. (minus 30 degrees C.). Before
the start of the cold season, coolant must be checked
with a hydrometer and if necessary, brought to the
necessary specific gravity by adding anti-freeze with
a glycol or glycerin base. As the specific gravities of
all anti- freeze solutions having a glycol or glycerin
base are practically the same, the hydrometer can be
used for all these types. Because of the tolerances of
the hydrometer, or slight differences in specific
gravity, variations of plus or minus 5 degrees can be
expected. Coolant must be checked at a temperature
of plus 68 degrees F. (plus 20 degrees C.)

6C- 361973 OPEL SERVICE MANUAL
FUEL SYSTEM
ALL MODELS
CONTENTS
Subject
DESCRIPTION AND OPERATION:
Fuel Pump. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . .Evaporation Control System
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DIAGNOSIS:
(Not Applicable)
MAINTENANCE AND ADJUSTMENTS:
Cleaning Fuel Pump Strainer.,....................................
*.Evaporation Control System
. . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MAJOR REPAIR:
Fuel Tank
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Fuel Lines and Fuel Tank Gauge Units
. . . . . . . . . . . . . . . . . . . . . .SPECIFICATIONS:
Fuel System Specifications
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page No.6C-366C-376C-376C-386C-396C-416C-41
DESCRIPTION AND OPERATION
FUEL PUMPThe 1.9 liter engine uses a push rod type fuel pump.
The push rod is actuated by an eccentric on the
distributor shaft. The push rod is held in contact
with the eccentric at all times by a push rod spring.
Each time the push rod is on the high part of the
eccentric, the lighter diaphragm spring will push the
diaphragm to replace any fuel used in the carburetor.
The diaphragm seldom operates through a full
stroke; under normal driving conditions, the dia-
phragm moves only a few tenths of an inch.
Fuel pump pressure is determined by the compres-
sion of the diaphragm spring. Low pressure or pres-
sure leak- down generally indicates a leaky
diaphragm or check valves.
Two holes in the lower part of the fuel pump serve
to ventilate the space below the diaphragm and to
drain any fuel which may have entered. If any fuel
comes from these holes, this indicates a defective
diaphragm.When replacing the fuel pump, make sure the asbe-
stos spacer is in place with a gasket on each side. See
Figure 6C- 1. Because of the location of the fuel pump
eccentric on the distributor shaft, the fuel pump
Figure
6C-1 Installing Push Rod Type Fuel Pump

CARBURETOR AND THROTTLE LINKAGE6E- 49DIAGNOSIS
CARBURETORCondition I
Hesitation or Stall Upon Light AccelerationCorrection
1. Check spark plugs and plug gap. Plug gap should
be
,030 in.
2. Check dwell and timing.
3. Adjust carburetor.
4. Accelerator pump should discharge fuel between
throttle plate and venturi wall with engine off. If aim
is not correct, use needlenose pliers to slightly bend
nozzle so proper aim is achieved. See Figure 6E- 10.
CORRECT ACCELERATOR
PUMP DISCHARGE
NOZZLE AIM
\Figure 6E-10 Pump Shot Aim
Road test car. If hesitation still exists, check for the
folI0 wing:1. Plugged accelerator pump discharge nozzle.2. Dirt in accelerator pump circuit.
3. Defective inlet check ball.
4. Defective accelerator pump pressure relief valve.
5. Defective accelerator pump diaphragm.
6. Maladjusted accelerator pump linkage.
Condition II
Hard Start Afier Hot Soak
CorrectionPerform Steps l-4 in Condition I.
Condition Ill
Hard Start When Engine Is Cold
Correction1. Align groove on choke cover with pointer on
choke housing. See Figure
6E-17.2. Set fast idle.
3. Replace distributor points if pitted.
4. Check spark plugs and gap at
,030.5. Set dwell and timing.
If above procedure does not correct problem, replace
with new automatic choke assembly.
Condition IV
Rough, Erratic, or No Idle
Correction1. Check spark plugs and gap at
,030.2. Check dwell angle and ignition timing.
3. Clean idle jet and passages with air hose. See Fig-
ure
6E-5.4. Check manifold to head bolt torque. Should be 33
lb.ft.5. Check automatic choke linkage alignment.
6. Adjust carburetor.