1991 MAZDA MIATA crankshaft

A/C-HEATER SYSTEM - MANUAL
1990-92 Manual A/C-Heater Systems
A/C SYSTEM SPECIFICATIONS
A/C SYSTEM SPECIFICATIONS
DESCRIPTION
Blower case, mounted under right end of instrument panel, contains blower motor and fresh/recirculated air
door. Evaporator case, to left of blower case, contains evaporator, evaporator thermoswitch and expansion
valve. Heater case, to left of evaporator case, contains airflow mode door and air-mix (temperature blend) door.
ELECTRICAL COMPONENT LOCATIONS
OPERATION
All air control doors are controlled manually by cable from control panel. Top lever controls the air-mix door,
center lever controls the fresh/recirculated air door and bottom lever controls the airflow mode door.
ApplicationSpecification
Compressor TypeNippondenso Rotary Vane
Compressor Belt Deflection (1) (2)
New5/16-23/64" (8-9 mm)
Used23/64-25/64" (9-10 mm)
Compressor Oil Capacity2.7-3.3 oz.
Refrigerant (R-12) Capacity28 oz.
System Operating Pressures
High Side171-235 psi (12.0-16.5
kg/cm
2 )
Low Side21-43 psi (1.5-3.0 kg/cm2 )
(1)With 22 lbs. (10 kg) pressure applied to center of belt.
(2)On vehicles with P/S, measure midway between crankshaft pulley and P/S pump pulley. On vehicles
without P/S, measure midway between crankshaft pulley and A/C idler pulley.
ComponentLocation
A/C RelayIn Right Front Corner Of Engine Compartment
Blower Motor RelayIn Left Rear Corner Of Engine Compartment
Blower ResistorOn Bottom Of Blower Case
Evaporator Thermoswitch. On Left Side Of Evaporator Case
Pressure SwitchIn High-Pressure Line, Between Receiver-Drier
And Evaporator

1991 Mazda MX-5 Miata
A/C-HEATER SYSTEM - MANUAL 1990-92 Manual A/C-Heater Systems

1991 Mazda MX-5 Miata
A/C-HEATER SYSTEM - MANUAL 1990-92 Manual A/C-Heater Systems
Microsoft
Sunday, July 05, 2009 2:11:52 PMPage 1 © 2005 Mitchell Repair Information Company, LLC.
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Sunday, July 05, 2009 2:11:56 PMPage 1 © 2005 Mitchell Repair Information Company, LLC.

MAZDA
1.6L & 1.8L 4-Cylinder - 1986-95
MANUFACTURER'S SUGGESTED SCHEDULED MAINTENANCE
For 1992 and earlier model years, the manufacturer recommends the belt be replaced every 60,000 miles. For
1993-95 model years, the manufacturer recommends the belt be replaced at 60,000 mile intervals for vehicles
sold outside of California. For vehicles sold in California, inspect timing belt at 60,000 and 90,000 miles, and
replace timing belt at 105,000 miles.
REMOVAL & INSTALLATION
TIMING BELT
Removal (MX-3, Protege & 323)
1. Disconnect negative battery cable. Raise and support vehicle. Remove right front wheel. Remove right
splash panels.
2. Remove drive belts and water pump pulley. See Fig. 1
, Fig. 2 or Fig. 3 . Align crankshaft pulley timing
mark with cylinder No. 1 at TDC of compression stroke. Hold crankshaft stationary, and remove
crankshaft pulley bolts and pulley. Remove crankshaft pulley hub bolt and hub.
3. Remove timing belt covers. If timing belt is to be reused, mark timing belt rotation direction. Align
timing marks on camshaft sprocket(s). See Fig. 4
(SOHC) or Fig. 5 (DOHC) . Loosen timing belt
tensioner lock bolt. Temporarily secure tensioner away from belt with spring fully expanded. Remove
timin
g belt.

1991 Mazda MX-5 Miata
MAZDA 1.6L & 1.8L 4-Cylinder - 1986-95

1991 Mazda MX-5 Miata
MAZDA 1.6L & 1.8L 4-Cylinder - 1986-95
Microsoft
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Sunday, July 05, 2009 2:12:56 PMPage 1 © 2005 Mitchell Repair Information Company, LLC.

Fig. 5: Aligning Camshaft Timing Marks (DOHC 1.8L Engines)
Courtesy of MAZDA MOTORS CORP.
Removal (MX-5 Miata - DOHC)
1. Disconnect negative battery cable. Drain cooling system. Remove radiator hose and by-pass hoses from
thermostat housing. Remove air cleaner intake duct assembly from throttle body to air cleaner filter
housing. Remove splash shield.
2. Remove drive belt(s) and water pump pulley. See Fig. 6
. Align crankshaft pulley timing mark with
cylinder No. 1 at TDC of compression stroke. Hold crankshaft pulley stationary. Remove crankshaft
pulley bolts. Remove pulley. Remove crankshaft pulley hub bolt and hub.
3. Remove cylinder head cover. Remove upper, center and lower timing belt cover. If timing belt is to be
reused, mark timing belt rotation direction. Ensure timing marks on camshaft sprockets are aligned. See
Fig. 7
. Loosen timing belt tensioner lock bolt, and move tensioner away from belt with spring fully
expanded. Remove timin
g belt.

1991 Mazda MX-5 Miata
MAZDA 1.6L & 1.8L 4-Cylinder - 1986-95
Microsoft
Sunday, July 05, 2009 2:12:44 PMPage 6 © 2005 Mitchell Repair Information Company, LLC.

Check timing belt for cracks, peeling, abrasion or other damage. Check tensioner bearing for looseness or
roughness of rotation. Inspect tensioner spring for stretching. Replace parts as necessary.
Installation (All Models)
1. Position notch on crankshaft sprocket to 12 o'clock position (aligned with mark on oil pump). Align
timing marks on camshaft sprocket(s). For SOHC, see Fig. 4
. For DOHC, see Fig. 5 or Fig. 7 . Ensure
crankshaft timing mark is at TDC. Install belt around crankshaft sprocket, then working in a
counterclockwise direction, route belt around camshaft sprocket(s).
2. Loosen timing belt tensioner lock bolt, and allow spring to apply tension on belt. Snug tensioner lock
bolt. Rotate crankshaft 2 complete turns in direction of normal engine rotation. Ensure timing marks
align. If timing marks are not aligned, remove belt, realign all timing marks, and repeat installation
procedure.
3. On all engines, check timing belt deflection with 22 lbs. (10 kg) of pressure applied to belt. See Fig. 8
.
Ensure timing belt deflection is within specification. See TIMING BELT DEFLECTION
table. Adjust
drive belts to proper tension.
TIMING BELT DEFLECTION
Application(1) Deflection - In. (mm)
1986-89.47-.51 (11.9-13.0)
1990-95
DOHC.35-.45 (9.0-11.5)
SOHC.43-.51 (11.0-13.0)
(1)Deflection measurement is with 22 lbs. (10 kg) of pressure applied to timing belt. See Fig. 8.

1991 Mazda MX-5 Miata
MAZDA 1.6L & 1.8L 4-Cylinder - 1986-95
Microsoft
Sunday, July 05, 2009 2:12:44 PMPage 9 © 2005 Mitchell Repair Information Company, LLC.

Courtesy of MAZDA MOTORS CORP.
TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS
ApplicationFt. Lbs. (N.m)
A/C Compressor Bracket
MX-3, Protege & 32317-26 (23-35)
MX-5 Miata11-16 (15-22)
Alternator Top Bolt27-38 (37-52)
Camshaft Sprocket Bolt36-45 (49-61)
Crankshaft/Timing Belt Sprocket Bolt
1986-9180-87 (109-118)
1992-95116-123 (157-167)
Power Steering Pump-To-Bracket Bolt
MX-3, Protege & 32327-38 (37-52)
Timing Belt Tensioner Bolt
DOHC27-38 (37-52)
SOHC14-19 (19-26)
INCH Lbs. (N.m)
Camshaft/Rocker Cover Bolt
DOHC & SOHC (Top)43-78 (5-9)
SOHC (Timing Belt Cover-To-Camshaft Cover)69-95 (8-11)
Crankshaft Pulley Bolts109-152 (12-17)

1991 Mazda MX-5 Miata
MAZDA 1.6L & 1.8L 4-Cylinder - 1986-95
Microsoft
Sunday, July 05, 2009 2:12:44 PMPage 11 © 2005 Mitchell Repair Information Company, LLC.