Mazda MX-5 Miata / Grand Touring. Manual - part 132

Fig. 2: Identifying Removal Order Of Ignition Coil (With Torque Specifications) 
Courtesy of MAZDA MOTORS CORP. 

IGNITION COIL INSPECTION [LF] 

IGNITION COIL INSPECTION 

1. Perform the spark test and identify the malfunctioning cylinder.  

2. Replace the ignition coil of the malfunctioning cylinder with that of a normal cylinder, and re-perform the 

spark test. 



If the spark is not normal due to a malfunctioning ignition coil, replace that ignition coil.  



It is unlikely that all four ignition coils fail to operate properly. To prevent replacing a normal 
component, perform the above procedure, identify the malfunctioning ignition coil, and replace it. 

 

2008 Mazda MX-5 Miata Grand Touring 

2008 ENGINE Ignition System - MX-5 Miata

  

IGNITION COIL WITH BUILT-IN IGNITER INSPECTION

1. Disconnect the ignition coil connector.  

2. Measure the resistance between each terminal on the ignition coil connector using an analog circuit tester. 



If the measurement corresponds to the table, replace the ignition coil.  

TESTER CONNECTION POSITION 

Item

Tester Connection Position

Condition

Positive

Negative

Terminal

C

A

0 ohm is not normal 

(Infinity ohm is normal)

A

C

C

B

B

C

A

B

Infinity or 0 ohm is not 

normal (several kilohm is 

normal)

B

A

 

2008 Mazda MX-5 Miata Grand Touring 

2008 ENGINE Ignition System - MX-5 Miata

  

Fig. 3: Identifying Ignition Coil Connector Terminals 
Courtesy of MAZDA MOTORS CORP. 

SPARK PLUG REMOVAL/INSTALLATION [LF] 

 

2008 Mazda MX-5 Miata Grand Touring 

2008 ENGINE Ignition System - MX-5 Miata

  

1. Remove the battery cover.  

2. Disconnect the negative battery cable. (See BATTERY REMOVAL/INSTALLATION [LF] .)  

3. Remove the plug hole plate. (See PLUG HOLE PLATE REMOVAL/INSTALLATION [LF] .)  

4. Remove the front suspension tower bar (joint). (See FRONT SUSPENSION TOWER BAR 

REMOVAL/INSTALLATION .)  

5. Remove the ignition coils. (See IGNITION COIL REMOVAL/INSTALLATION [LF] .)  

6. Remove the spark plugs using a plug-wrench.  

7. Install in the reverse order of removal. 

Tightening torque  

10-14 N.m {1.1-1.4 kgf.m. 8-10 ft.lbf}  

SPARK PLUG INSPECTION [LF] 

SPECIFICATION 

Spark plug type  

L3G2 18 110, L3Y1 18 110  

PLUG GAP INSPECTION 

1. Measure the spark plug gap using a wire type plug gap gauge. 



If it exceeds the specification, replace the spark plug.  

Spark plug gap  

1.25-1.35 mm {0.050-0.053 in}  

CLEANING 

CAUTION:



If a spark plug that is not as specified is installed, engine 
performance will be deteriorated. Install only the specified spark plug 
when replacing.  

CAUTION:



To avoid possible damage to the tip, do not adjust the plug gap.  



To prevent damaging the tip, use a wire type plug gap gauge when 
inspecting the plug gap.  

CAUTION:



Carbon may adhere to the tip of the spark plug during vehicle 
delivery or repeated short distance driving during the winter time. If 

 

2008 Mazda MX-5 Miata Grand Touring 

2008 ENGINE Ignition System - MX-5 Miata