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Engine Controls - Service & Adjustment Specifications: Other Mazda MX-5 NB

Specifications 3 illustrations ~585 words

ENGINE COMPRESSION

Warm engine to normal operating temperature. Remove all spark plugs. Disconnect ignition coil primary wire connector. Hold throttle plate fully open. Crank engine and note compression pressure.

ApplicationMinimum psi (kg/cm 2 ) @ RPMStandard psi (kg/cm 2 ) @ RPM
B2500(1)(1)
B3000 & B4000(1)(1)
Miata146 (10.3) @ 300209 (14.7) @ 300
Millenia (2)
2.3L121 (8.5) @ 250164 (11.5) @ 250
2.5L132 (9.3) @ 300189 (13.3) @ 300
Protege (2)
1.6L146 (10.3) @ 300195 (13.7) @ 300
1.8L156 (11.0) @ 300199 (14.0) @ 300
626 (2)
2.0L119 (8.4) @ 300171 (12.0) @ 300
2.5L141 (9.9) @ 250203 (14.3) @ 250
(1) Lowest compression reading should not be less than 75 percent of highest compression reading. (2) Difference between cylinders should not be more than 28 psi (2.0 kg/cm 2 ).
(1)Lowest compression reading should not be less than 75 percent of highest compression reading.
(2)Difference between cylinders should not be more than 28 psi (2.0 kg/cm 2 ).

COMPRESSION SPECIFICATIONS

ApplicationSpecification
B25009.4:1
B30009.14:1
B40009.0:1
Miata9.5:1
Millenia
2.3L10.0:1
2.5L9.2:1
Protege
1.6L9.0:1
1.8L9.0:1
626
2.0L9.0:1
2.5L9.5:1

COMPRESSION RATIO

VALVE CLEARANCE

Application(1) In. (mm)
Miata
Intake.008-.009 (.18-.24)
Exhaust.012-.013 (.30-.34)
Millenia 2.3L.011-.012 (.28-.30)
Protege
1.6L.010-.012 (.25-.30)
1.8L.009-.012 (.22-.30)
626
2.0L.009-.012 (.22-.30)
2.5L
Intake.010-.012 (.25-.30)
Exhaust.011-.013 (.27-.34)
All Others(2)
(1) Adjust valves with engine cold. (2) Engines are equipped with hydraulic valve lash adjusters. Valve clearance is not adjustable.
(1)Adjust valves with engine cold.
(2)Engines are equipped with hydraulic valve lash adjusters. Valve clearance is not adjustable.

VALVE CLEARANCE SPECIFICATIONS

IGNITION COIL

ApplicationPrimarySecondary
B2500, B3000 & B4000(1)(1)
Miata(1)8240-12360
Millenia.49-.7320,000-31,000
Protege(1)(1)
626
2.0L.45-.5511,500-15,500
2.5L.45-.5511,500-15,500
(1) Information is not available from manufacturer.
(1)Information is not available from manufacturer.

IGNITION COIL RESISTANCE - OHMS @ 68°F (20°C)

CRANKSHAFT POSITION SENSOR

ApplicationOhms @ 68°F (20°C)
B2500, B3000 & B4000300-800
Miata(1)
Millenia
2.3L950-1250
2.5L520-580
Protege500-600
626520-580
(1) Information is not available from manufacturer.
(1)Information is not available from manufacturer.

CRANKSHAFT POSITION SENSOR RESISTANCE

HIGH TENSION WIRE RESISTANCE

On B2500, B3000 and B4000, high tension wire resistance should measure 22,900 ohms per 3.28 feet (1.0M) at 68°F (20°C). On all other models, high tension wire resistance should measure 16,000 ohms per 3.28 feet (1.0M) at 68°F (20°C).

SPARK PLUGS

ApplicationNGK No.
B2500 & B3000(1) AWSF-32F
B3000(1) AWSF-32PP
B4000(1) AGSF-22PP
MiataBKR5E-11
Millenia
2.3LPZFR5F, PZFR6F or PZFR7F
2.5LZFR5F-11 or ZFR6F-11
Protege
1.6LZFR5F-11 or ZFR6F-11
1.8LBKR5E-11 or BKR6E-11
626
2.0LBKR5E-11 or BKR6E-11
2.5L(2) PKJ16CR8 or PKJ20CR8
(1) Motorcraft spark plug number. (2) Nippon Denso spark plug number.
(1)Motorcraft spark plug number.
(2)Nippon Denso spark plug number.

SPARK PLUG TYPE

ApplicationGap In. (mm)Torque Ft. Lbs. (N.m)
B2500 & B3000.42-.46 (1.1-1.2)7-14 (9-20)
B4000.52-.56 (1.3-1.4)10-14 (14-20)
Millenia
2.3L.028-.031 (.7-.8)11-16 (15-22)
2.5L.040-.043 (1.0-1.1)11-16 (15-22)
626
2.0L.040-.043 (1.0-1.1)11-16 (15-22)
2.5L.028-.031 (.7-.8)11-16 (15-22)
All Others.040-.043 (1.0-1.1)11-16 (15-22)
(1) Gap is not adjustable. For spark plug gap specification, refer to vehicle emission control identification decal located in engine compartment.
(1)Gap is not adjustable. For spark plug gap specification, refer to vehicle emission control identification decal located in engine compartment.

SPARK PLUG SPECIFICATIONS (1)

IGNITION TIMING

ApplicationMan. Trans.(1) Auto. Trans.
B2500 & B300010 @ Idle10 @ Idle
B40008-10 @ Idle8-10 @ Idle
Miata9-11@ 8009-11@ 800
Millenia (2)N/A6-8 @ 650
Protege (2)9-11 @ 7509-11 @ 750
626
2.0L6-18 @ 550-8506-18 @ 500-800
2.5L4-16 @ 550-7504-16 @ 550-750
(1) Place automatic transmission in Park. (2) Connect a jumper wire between terminals TEN and GND of data link connector. (Scheme 10)
(1)Place automatic transmission in Park.
(2)Connect a jumper wire between terminals TEN and GND of data link connector. (Scheme 10)

IGNITION TIMING SPECIFICATIONS (DEGREES BTDC @ RPM)

Scheme 10

Scheme 10
Scheme 10

FUEL PUMP

Note. Fuel pump performance measures fuel pressure, not regulated fuel pressure.

ApplicationPressure psi (kg/cm 2 )
B2500, B3000 & B400055-71 (3.8-5.0)
Miata92 (6.5)
Millenia71-92 (5.0-6.5)
Protege64-92 (4.5-6.5)
62671-92 (5.0-6.5)

FUEL PUMP PERFORMANCE

ApplicationAt Idle W/ Vacuum psi (kg/cm 2 )At Idle W/O Vacuum psi (kg/cm 2 )
B2500, B3000 & B4000(1)(1)
Miata53-61 (3.7-4.3)(1)
Millenia
2.3L30-41 (2.1-2.9)41-48 (2.8-3.4)
2.5L30-38 (2.1-2.7)38-45 (2.7-3.2)
Protege30-36 (2.1-2.6)38-45 (2.7-3.2)
626
2.0L30-38 (2.1-2.7)36-46 (2.6-3.3)
2.5L30-36 (2.1-2.6)38-45 (2.7-3.2)
(1) Information not available from manufacturer.
(1)Information not available from manufacturer.

REGULATED FUEL PRESSURE

Fuel Line Pressure

  1. Install Fuel Pressure Gauge (49 UN01 010) to fuel pressure relief valve (Schrader valve) located on fuel rail. Turn ignition on with engine off. Connect New Generation Star (NGS) scan tool to Data Link Connector (DLC). Connector is located under left side of instrument panel, right of steering column. Using scan tool, select ACTIVATE COMMAND MODES. Select OUTPUT TEST MODE. Press MODE to change to ALL ON mode. Press start to run fuel pump. Turn relay off. Observe fuel pressure.
  2. Fuel pressure should be 30-45 psi (2.0-3.1 kg/cm 2 ). If pressure is zero or low, check fuel pump. See FUEL PUMP. If fuel pump is okay, check for plugged or restricted fuel line or fuel filter. If pressure is high, check for high pressure in fuel pressure regulator. See FUEL PRESSURE REGULATOR HIGH PRESSURE.
  3. Wait one minute and observe fuel pressure. Fuel pressure should be within 5 psi (.35 kg/cm 2 ) of reading in step 2). If fuel pressure is not as specified, check fuel pressure regulator diaphragm. See FUEL PRESSURE REGULATOR DIAPHRAGM. Also, check for injector fuel leakage. See INJECTOR FUEL LEAKAGE. If fuel pressure is as specified, check fuel line pressure under load. See FUEL LINE PRESSURE UNDER LOAD.
  1. Disconnect negative battery cable. Install fuel pressure gauge in fuel supply line. Reconnect negative battery cable. Locate data link connector in left side of engine compartment. Connect a jumper wire between data link connector terminals F/P and GND. Turn ignition on and observe fuel line pressure. See «FUEL LINE PRESSURE»(ref-91090-S12149934912009050400000) table.
  2. If fuel line pressure is high, replace fuel pressure regulator. If fuel line pressure is low, check fuel pump maximum pressure. See FUEL PUMP MAXIMUM PRESSURE. If fuel pump maximum pressure is as specified, check for plugged or restricted fuel line or fuel filter. Repair as necessary. If no problems are found, check pressure regulator hold pressure. See PRESSURE REGULATOR HOLD PRESSURE.
ApplicationPressure psi (kg/cm 2 )
Millenia
2.3L41-48 (2.8-3.4)
2.5L38-46 (2.7-3.2)
MPV38-46 (2.7-3.2)
Protege41-46 (2.8-3.2)
62638-46 (2.7-3.2)

FUEL LINE PRESSURE

INJECTOR RESISTANCE

ApplicationOhms
B2500, B3000 & B400011-18
Miata, Protege & 62612-16
Millenia13.8

INJECTOR RESISTANCE - Ohms @ 68°F (20°C)

IDLE SPEED & MIXTURE

Note. Idle mixture is not adjustable. If idle mixture is incorrect, see appropriate SELF-DIAGNOSTICS article.

ApplicationMan. Trans. RPM(1) Auto. Trans. RPM
B2500(2)(2)
B3000825-875875-925
B4000800-850725-775
Miata750-850750-850
MilleniaN/A600-700
Protege (3)650-750700-800
626
2.0L550-850500-800
2.5L550-750550-750
(1) Place automatic transmission in Park. (2) Information is not available from manufacturer. (3) Connect a jumper wire between terminals TEN and GND at data link connector. (Scheme 10)
(1)Place automatic transmission in Park.
(2)Information is not available from manufacturer.
(3)Connect a jumper wire between terminals TEN and GND at data link connector. (Scheme 10)

IDLE SPEED SPECIFICATIONS

THROTTLE POSITION (TP) SENSOR

Note. For information on connector terminal identification and test conditions specified in the following tables, see ON-VEHICLE ADJUSTMENTS article.

TP SENSOR CONTINUITY (MILLENIA & 626 2.5L)

Test Condition (1)Continuity Between Terminals "C" & "D"
Millenia
2.3L
.008" (.19 mm)Yes
.015" (.37 mm)No
2.5L
.006" (.15 mm)Yes
.020" (.50 mm)No
626
2.5L
.006" (.15 mm)Yes
.020" (.50 mm)No
(1) Insert feeler gauge of specified thickness between throttle lever and throttle stop screw.
(1)Insert feeler gauge of specified thickness between throttle lever and throttle stop screw.

TP SENSOR CONTINUITY (MILLENIA & 626 2.5L)

Scheme 11

Scheme 11
Scheme 11

TP SENSOR RESISTANCE (PROTEGE & 626)

Test Condition (1)(2) Ohms
Protege
1.6L2500-6000
1.8L4000-6000
626
2.0L4000-6000
2.5L2500-5000
(1) With throttle closed. (2) Between terminals "A" and "C". (Scheme 11)
(1)With throttle closed.
(2)Between terminals "A" and "C". (Scheme 11)

TP SENSOR RESISTANCE (PROTEGE & 626)

Scheme 12

Scheme 12
Scheme 12

THROTTLE POSITION (TP) SENSOR VOLTAGE (B2500, B3000 & B4000)

Throttle Valve Position (Degrees) (1)(2) PID Voltage
0.65
10.97
201.44
301.90
402.37
502.84
603.31
703.78
804.24
(1) TP sensor is not adjustable. (2) Check sensor voltage using New Generation Star (49 T088 0A0) scan tool connected to data link connector 2 located under left side of instrument panel, right of steering column.
(1)TP sensor is not adjustable.
(2)Check sensor voltage using New Generation Star (49 T088 0A0) scan tool connected to data link connector 2 located under left side of instrument panel, right of steering column.

THROTTLE POSITION (TP) SENSOR VOLTAGE (B2500, B3000 & B4000)

TP SENSOR VOLTAGE (MIATA, MILLENIA, PROTEGE & 626)

ECM/PCM Wire Color (1)Closed Throttle VoltsWide Open Throttle Volts
Miata
Green/Black (3E).1-1.13.0-4.6
Millenia
2.3L
Yellow (3B).1-1.12.8-4.5
2.5L
Yellow/Red (3B).1-1.02.8-4.5
Protege
1.6L
Blue/Yellow (3D).1-1.13.0-4.6
1.8L
Blue/Yellow (3F).1-1.13.0-4.6
626
2.0L
Violet/Yellow (89).3-0.73.4-5.3
2.5L
Violet/Yellow (89).3-1.02.8-4.5
(1) Measure voltage between ground and ECM/PCM terminal No. in parentheses.
(1)Measure voltage between ground and ECM/PCM terminal No. in parentheses.

TP SENSOR VOLTAGE (MIATA, MILLENIA, PROTEGE & 626)

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