compression ratio MITSUBISHI MONTERO 1991 Service Manual

Page 12 of 1333

Fig. 8: Aligning Timing Marks (SOHC)
Courtesy of Mitsubishi Motor Sales of America, Inc.
Inspection (Montero & Pickup)
Inspect timing belt for wear on edges of drive teeth. Inspect
belt for oil contamination, cracks, separation, worn or missing teeth
and hardened back surface. Replace belt if worn, damaged or
contaminated. Inspect belt tensioner for smooth rotation. Replace if
defective.
Installation (Montero & Pickup)
1) Install rear timing belt cover. Tighten bolts to
specification. See TORQUE SPECIFICATIONS (MONTERO & PICKUP) table at
end of article. Install camshaft sprockets (if removed). Using holder,\
hold camshaft and tighten retaining bolt to specification.
2) Install belt tensioner and spring. Ensure spring is
secured on pin of water pump and engaged in hole of belt tensioner
with hook of spring pointing from cylinder block.
3) Rotate belt tensioner counterclockwise as much as
possible, and temporarily tighten bolt. Align all timing marks with
No. 1 cylinder at TDC of compression stroke. See Fig. 8.
4) Install timing belt on crankshaft sprocket and then left
camshaft sprocket with all slack removed from tension side of belt.
Route timing belt onto water pump pulley, right camshaft sprocket and
tensioner. Remove any slack from belt by rotating left and then right
camshaft sprockets counterclockwise.
5) Ensure belt is installed in original direction of rotation
and all timing marks are aligned. Install flange on crankshaft. Loosen
belt tensioner bolts slightly, and allow tensioner to apply belt
tension.
6) Using Crankshaft Socket (MD998716), rotate crankshaft 2

Page 35 of 1333

Rear Engine Support
Bracket-To-Engine Bolt .................... 13-18 (18-25)
Relief Valve Plug ................................ 33 (45)
Rocker Shaft ............................... 14-15 (19-20)
Roll Stopper Bracket Through Bolts ......... 36-43 (49-58)
Turbocharger-To-Exhaust Fitting ............ 40-47 (54-64)
Timing Belt Tensioner Bolt ....................... 31 (42)
Water Pump Bolt .................................. 17 (23)
INCH Lbs. (N.m)
Delivery Pipe Bolt .............................. 108 (12)
Oil Pan Bolt ................................. 48-60 (5-7)
Oil Pump Cover Bolt .............................. 96 (11)
Rear Seal Case Bolt .............................. 96 (11)
Rocker Cover Bolt
SOHC ....................................... 72-84 (8-9)
DOHC ............................................ 26 (3)
Throttle Body Bolt ......................... 84-108 (9-12)
Timing Belt Cover Bolt ..................... 84-108 (9-12)
Transmission Mounting Plate Bolt ........... 84-108 (9-12)
( 1) - Tighten in 2 steps using proper sequence.
See Fig. 4.
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ENGINE SPECIFICATIONS
GENERAL ENGINE SPECIFICATIONS
GENERAL SPECIFICATIONS TABLE\
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Application Specification
3.0L V6 DOHC Non-Turbo
Displacement ....................... 181.4 Cu. In. (3.0L)
Bore ................................... 3.587" (91.1 mm)
Stroke ................................. 2.992" (76.0 mm)
Compression Ratio ................................ 10.0:1
Fuel System ......................................... PFI
Horsepower @ RPM ............................. 222 @ 6000
Torque Ft. Lbs. @ RPM ........................ 201 @ 4500
3.0L V6 DOHC Turbo
Displacement ....................... 181.4 Cu. In. (3.0L)
Bore ................................... 3.587" (91.1 mm)
Stroke ................................. 2.992" (76.0 mm)
Compression Ratio ................................. 8.0:1
Fuel System ......................................... PFI
Horsepower @ RPM ............................. 300 @ 6000
Torque Ft. Lbs. @ RPM ........................ 307 @ 2500
3.0L V6 SOHC
Displacement ....................... 181.4 Cu. In. (3.0L)
Bore ................................... 3.587" (91.1 mm)
Stroke ................................. 2.992" (76.0 mm)
Compression Ratio ................................. 8.9:1
Fuel System ......................................... PFI
Horsepower @ RPM ............................. 143 @ 5000
Torque Ft. Lbs. @ RPM ........................ 168 @ 2500
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(such as compression
fitting) ............... B ............ Require replacement.
Flange leaking .......... A .. Require repair or replacement.
Leaking ................. A .. Require repair or replacement.
Restricted internally ... A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
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EXPANSION VALVES
EXPANSION VALVE 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.
Corroded internally ..... 1 ............ Suggest replacement.
Filter screen torn ...... A .. Require replacement of screen.
Inoperative ............. A ........... ( 1) Require repair or
replacement.
Leaking ................. A ............ Require replacement.
Restricted .............. A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A ............ Require replacement.
( 1) - Expansion valve operation may be affected by capillary
tube location, corrosion, and insulation tape.
Inoperative includes intermittent operation.
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FUNCTION SELECTORS
See CONTROL HEADS (FUNCTION SELECTORS) .
FUSES, FUSIBLE LINKS AND CIRCUIT BREAKERS
FUSE, FUSIBLE LINK AND CIRCUIT BREAKER INSPECTION\
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Condition Code Procedure
Application incorrect ... B ............ Require replacement.
Blown ................... A ........ ( 1) Require replacement.
Corroded, affecting
performance ............ A .. Require repair or replacement.
Corroded, not affecting
performance ............ 2 .. Suggest repair or replacement.
Cracked, affecting
performance ............ A .. Require repair or replacement.
Cracked, not affecting
performance ............ 1 .. Suggest repair or replacement.
Inoperative ............. A ... ( 2) Require replacement.
Insulation damaged,

Page 137 of 1333

\003
D - A D JU STM EN TS

1991 M it s u bis h i M onte ro
1991 ENGINE PERFORMANCE
On-Vehicle Adjustments
Chrysler Motors: Colt, Colt 200, Colt Vista,
Ram-50, Stealth, Summit
Mitsubishi: Eclipse, Galant, Mirage, Montero,
Pickup, 3000GT
ENGINE MECHANICAL
Before performing any on-vehicle adjustments to fuel or
ignition system, ensure engine mechanical condition is okay.
VALVE CLEARANCE
NOTE: All engines except 1.5L use hydraulic valve lifters. Valve
adjustment is only required on 1.5L engines. To check
hydraulic valve lifter operation, see CHECKING HYDRAULIC
VALVE LIFTERS.
MECHANICAL VALVE LIFTERS
CAUTION: DO NOT rotate crankshaft in opposite direction of normal
engine rotation.
1.5L
1) Ensure engine is at normal operating temperature. Remove
all spark plugs and valve cover. Rotate crankshaft to position
cylinder No. 1 on TDC of compression stroke. Adjust intake valves on
cylinders No. 1 and No. 2, and exhaust valves on cylinders No. 1 and
No. 3. See VALVE CLEARANCE ADJUSTMENT table for specification.
2) Rotate crankshaft 360 degrees to position cylinder No. 4
on TDC of compression stroke. Adjust intake valves on cylinders No. 3
and No. 4, and exhaust valves on cylinders No. 2 and No. 4.
VALVE CLEARANCE ADJUSTMENT TABLE
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Cold Hot
Application In. (mm) In. (mm)
Intake ............ .003 (.07) ......... .006 (.15)
Exhaust ........... .007 (.17) ......... .010 (.25)
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CHECKING HYDRAULIC VALVE LIFTERS
Except 1.5L
1) Remove valve cover. Push downward on end of rocker arm
above lash adjuster. If lash adjuster is normal, it will feel hard. If
lash adjuster moves downward easily when pushed, replace adjuster.
2) If lash adjuster feels soft or spongy, oil with air has
probably entered lash adjuster. If this occurs, check engine oil
level. If engine oil level is okay, check oil screen and oil screen
gasket for damage.
3) After repairing cause of air leak, warm engine to
operating temperature. Drive vehicle at low speed for approximately 5
minutes. Turn engine off for a few minutes.
4) Restart engine and drive at low speed for approximately 5

Page 199 of 1333

specifications.
Wire lead open .......... A .. Require repair or replacement.
Wire lead shorted ....... A .. Require repair or replacement.
(1) - If a sensor is not adjustable, further inspection is
required to identify and correct cause.
( 2) - Determine cause and correct prior to repair or
replacement of part.
( 3) - Determine source of contamination, such as metal
particles or water. Require repair or replacement.
( 4) - Inoperative includes intermittent operation or out of OEM
specification. Some components may be serviceable; check
for accepted cleaning procedure.
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STEEL BRAKE LINES
STEEL BRAKE LINE INSPECTION\
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Condition Code Procedure
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.
Corroded, affecting
structural integrity ... A ............ Require replacement.
Fitting incorrect (for
example, compression
fitting) ............... B ............ Require replacement.
Flare type incorrect .... B .. Require repair or replacement.
Leaking ................. A .. Require repair or replacement.
Line material incorrect
(copper, etc.) ......... B ............ Require replacement.
Restricted .............. A ............ Require replacement.
Routed incorrectly ...... B ..... Require routing correction.
Rust-pitted ............. 1 ............ Suggest replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped
(threads missing) ...... A ............ Require replacement.
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STOPLIGHT SWITCHES
See BRAKE STOPLIGHT SWITCHES .
SWITCHES
NOTE: Copied from Electrical UIGs & added "float saturated" from
old fluid level sensor switches.
STEEL BRAKE LINE INSPECTION
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Condition Code Procedure
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.

Page 602 of 1333

complete cooling system. Test components as follows, following tool
manufacturer's instructions.
Radiator Cap
Visually inspect radiator cap, then dip cap into water and
connect to tester. Pump tester to bring pressure to upper limit of cap
specification. If cap fails to hold pressure, replace cap.
Fig. 2: Testing Radiator Pressure Cap
Cooling System
1) With engine off, wipe radiator filler neck seat clean.
Fill radiator to correct level. Attach tester to radiator and pump
until pressure is at upper level of radiator rating.
2) If pressure drops, inspect for external leaks. If no leaks
are apparent, detach tester and run engine until normal operating
temperature is reached. Reattach tester and observe. If pressure
builds up immediately, a possible leak exists from a faulty head
gasket or crack in head or block.
NOTE: Pressure may build up quickly. Release any excess pressure
or cooling system damage may result.
3) If there is no immediate pressure build up, pump tester to
within system pressure range (on radiator cap). Vibration of gauge
pointer indicates compression or combustion leak into cooling system.
Isolate leak by shorting each spark plug wire to cylinder block. Gauge
pointer should stop or decrease vibration when leaking cylinder is
shorted.

Page 739 of 1333

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MECHANICAL CHECKS
ENGINE COMPRESSION
Check engine compression with engine at normal operating
temperature at specified cranking speed, all spark plugs removed and
throttle wide open.
COMPRESSION SPECIFICATIONS
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Application (1) Specification
Compression Ratio
1.5L (VIN A) ...................... 9.4:1
1.6L (VIN Y) ...................... 9.2:1
1.8L (VIN T) ...................... 9.0:1
2.0L (VIN R) ...................... 9.0:1
2.0L (VIN U) ...................... 9.0:1
2.0L (VIN V) ...................... 8.5:1
2.4L (VIN W) ...................... 8.5:1
3.0L (VIN B) ..................... 10.0:1
3.0L (VIN C) ...................... 8.0:1
3.0L (VIN S) ...................... 8.9:1
Compression Pressure ( 2)
1.5L (VIN A) ....... 137 psi (9.6 kg/cm
)
1.6L (VIN Y) ...... 171 psi (12.0 kg/cm)
1.8L (VIN T) ....... 131 psi (9.2 kg/cm)
2.0L (VIN R) ....... 137 psi (9.6 kg/cm)
2.0L (VIN U) ....... 114 psi (8.0 kg/cm)
2.0L (VIN V) ....... 119 psi (8.4 kg/cm)
2.4L (VIN W) ....... 119 psi (8.4 kg/cm)
3.0L (VIN B) ....... 139 psi (9.8 kg/cm)
3.0L (VIN C) ....... 115 psi (8.1 kg/cm)
3.0L (VIN S) ....... 119 psi (8.4 kg/cm)
( 1) - See A - ENGINE/VIN ID article in the
ENGINE PERFORMANCE Section for VIN
information.
( 2) - Maximum variation between cylinders is
14 psi (1.0 kg/cm
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VALVE CLEARANCE
NOTE: Valve adjustment is required on 1.5L engines only. Check
adjustment at 15,000 mile intervals.
VALVE CLEARANCE SPECIFICATIONS - 1.5L
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Application ( 1) In. (mm)
Hot Engine
Intake ....................... .006 (.15)
Exhaust ...................... .010 (.25)
Cold Engine
Intake ....................... .003 (.07)
Exhaust ...................... .007 (.17)
( 1) - Adjust valves with engine hot.
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Page 1206 of 1333

Excessive Oil Worn valve stems or guides Replace stems or
Consumption guides, See ENGINES
Valve "O" ring seals Replace "O" ring seals,
damaged See ENGINES
Plugged oil drain back holes Remove restrictions
Improper PCV valve Replace PCV valve
operation
Engine oil level too high Remove excess oil
Engine oil too thin Replace thicker oil
Valve stem oil deflectors Replace oil deflectors
damaged
Incorrect piston rings Replace piston rings,
See ENGINES
Piston ring gaps not Reinstall piston rings,
staggered See ENGINES
Insufficient piston ring Replace rings, See
tension ENGINES
Piston ring grooves or oil Replace piston rings,
return slots clogged See ENGINES
Piston rings sticking in Replace piston rings,
grooves See ENGINES
Piston ring grooves Replace piston and
excessively worn rings, See ENGINES
Compression rings installed Replace compression
upside down rings correctly, See
ENGINES
Worn or scored cylinder Rebore cylinders or
walls replace block
Mismatched oil ring Replace oil ring
expander and rail expander and rail, See
ENGINES
Intake gasket dowels too Replace intake gasket
long dowels
Excessive main or connecting Replace main or
rod bearing clearance connecting rod
bearings, See ENGINES
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No Oil Pressure Low oil level Add oil to proper level
Oil pressure sender or Replace sender or gauge
gauge broken
Oil pump malfunction Remove and overhaul oil
pump, See ENGINES
Oil pressure relief valve Remove and reinstall
sticking valve
Oil pump passages blocked Overhaul oil pump, See
ENGINES
Oil pickup screen or tube remove restriction
blocked
Loose oil inlet tube Tighten oil inlet tube
Loose camshaft bearings Replace camshaft
bearings, See ENGINES
Internal leakage at oil Replace block or
passages cylinder head
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Low Oil Pressure Low engine oil level Add oil to proper level
Engine oil too thin Remove and replace with
thicker oil
Excessive oil pump Reduce oil pump
clearance clearance, See ENGINES
Oil pickup tube or screen Remove restrictions
blocked
Main, rod or cam bearing Replace bearing to
clearance excessive reduce clearance, See

Page 1212 of 1333

batteries
Bad starter connections Check connections
or bad starter and/or replace
batteries
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Engine Cranks Bad battery connections Check connections
Slowly, Won't or dead batteries and/or replace
Start batteries
Engine oil too heavy Replace engine oil
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Engine Cranks Glow plugs not functioning Check glow plug system,
Normally, But see FUEL SYSTEMS
Will Not Start Glow plug control not Check controller, see
functioning FUEL SYSTEMS
Fuel not injected into Check fuel injectors,
cylinders see FUEL SYSTEMS
No fuel to injection pump Check fuel delivery
system
Fuel filter blocked Replace fuel filter
Fuel tank filter blocked Replace fuel tank
filter
Fuel pump not operating Check pump operation
and/or replace pump
Fuel return system blocked Inspect system and
remove restriction
No voltage to fuel solenoid Check solenoid and
connections
Incorrect or contaminated Replace fuel
fuel
Incorrect injection pump Re-adjust pump timing,
timing see FUEL SYSTEMS
Low compression Check valves, pistons,
rings, see ENGINES
Injection pump malfunction Inspect and/or replace
injection pump
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Engine Starts, Incorrect slow idle Reset idle adjustment,
Won't Idle adjustment see TUNE-UP
Fast idle solenoid Check solenoid and
malfunctioning connections
Fuel return system blocked Check system and remove
restrictions
Glow plugs go off too soon See glow plug diagnosis
in FUEL SYSTEMS
Injection pump timing Reset pump timing, see
incorrect FUEL SYSTEMS
No fuel to injection pump Check fuel delivery
system
Incorrect or contaminated Replace fuel
fuel
Low compression Check valves, piston,
rings, see ENGINES
Injection pump malfunction Replace injection pump,
see FUEL SYSTEMS
Fuel solenoid closes in RUN Check solenoid and
position connections
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Engines Starts/ Incorrect slow idle Reset slow idle, see
Idles Rough W/out adjustment TUNE-UP
Smoke or Noise Injection line fuel leaks Check lines and
connections
Fuel return system blocked Check lines and
connections