Mazda MX-5 Miata / Grand Touring. Manual - part 117

2. Remove the battery cover.  

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

4. Remove the fuel tank with the fuel pump unit. (See FUEL TANK REMOVAL/INSTALLATION 

[LF] .)  

5. Perform the following procedure to verify the fuel tank airtightness. 

1. Plug the fuel pump unit pipe, port B and port C. 

Fig. 18: Identifying Plug Fuel Pump Unit Pipe & Ports 
Courtesy of MAZDA MOTORS CORP. 

2. Apply a pressure of 3 kPa {23 mmHg, 0.9 inHg} to port A and wait for a while.  

3. Verify that there is no air leakage from the fuel tank. 



If there is airflow, replace the fuel tank.  

6. Plug the fuel pump unit pipe and port B. 

 

2008 Mazda MX-5 Miata Grand Touring 

2008 ENGINE Fuel System - MX-5 Miata

  

Fig. 19: Identifying Plug 
Courtesy of MAZDA MOTORS CORP. 

7. Level the fuel tank.  

8. Apply a pressure of 3 kPa {23 mmHg, 0.9 inHg} to port C and wait for a while.  

9. With the pressure still applied, verify that there is airflow from port A and the pressure is 0- 3 kPa {0-22 

mmHg, 0- 0.8 inHg} . 



If there is no airflow, replace the fuel tank.  

10. Apply a pressure of -0.5 kPa {-3.8 mmHg, -0.1 inHg} to port C and wait for a while.  

11. With the pressure still applied, verify that there is airflow from port A and the pressure is -0.5- 0 kPa {-

3.8- 0 mmHg, -0.2- 0 inHg} . 



If there is no airflow, replace the fuel tank.  



If there is airflow, place the fuel tank upside down.  

12. Apply a pressure of 3 kPa {23 mmHg, 0.9 inHg} to port C and wait for a while.  

13. With the pressure still applied, verify that there is no airflow from port A. 



If there is airflow, replace the fuel tank.  

NON-RETURN VALVE INSPECTION [LF] 

WARNING:



Fuel is very flammable liquid. If fuel spills or leaks from the 

 

2008 Mazda MX-5 Miata Grand Touring 

2008 ENGINE Fuel System - MX-5 Miata

  

1. Follow "BEFORE SERVICE PRECAUTION" before performing any work operations to prevent fuel 

from spilling from the fuel system. (See BEFORE SERVICE PRECAUTION [LF] .)  

2. Remove the battery cover.  

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

4. Remove the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [LF] .)  

5. Siphon the fuel from the fuel tank. 

6. Verify that the non-return valve is closed. 



If the non-return valve is stuck open and dose not open even when pulled up by a finger, replace the 
fuel tank. (See FUEL TANK REMOVAL/INSTALLATION [LF] .)  

FUEL PUMP UNIT REMOVAL/INSTALLATION [LF] 

1. Follow "BEFORE SERVICE PRECAUTION" before performing any work operations to prevent fuel 

from spilling from the fuel system. (See BEFORE SERVICE PRECAUTION [LF] .)  

2. Remove the battery cover.  

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

4. Perform the following procedure to remove the service hole cover. 

1. To remove the back trim, remove the following parts: 

1. Console (See CONSOLE REMOVAL/INSTALLATION .)  

2. Quarter trim (See QUARTER TRIM REMOVAL/INSTALLATION .)  

pressurized fuel system, it will cause serious injury or death and 
facility breakage. Fuel can also irritate skin and eyes. To prevent 
this, always complete the "

FUEL LINE SAFETY PROCEDURE

", while 

referring to the "BEFORE SERVICE PRECAUTION [LF]".  

NOTE:



Non-return valve is integrated in the fuel tank.  



The non-return valve is normally closed by the spring force. 

WARNING:



Fuel is very flammable liquid. If fuel spills or leaks from the 
pressurized fuel system, it will cause serious injury or death and 
facility breakage. Fuel can also irritate skin and eyes. To prevent 
this, always complete the "

FUEL LINE SAFETY PROCEDURE

", while 

referring to BEFORE SERVICE PRECAUTION [LF] .  



Fuel is very flammable liquid. If fuel spills or leaks from the 
pressurized fuel system, it will cause serious injury or death and 
facility breakage. Fuel can also irritate skin and eyes. To prevent 
this, before performing the fuel pump unit removal/installation, 
always complete the "Fuel Leak Inspection After Fuel Pump Unit 
Installation".  

 

2008 Mazda MX-5 Miata Grand Touring 

2008 ENGINE Fuel System - MX-5 Miata

  

3. Scuff plate (See SCUFF PLATE REMOVAL/INSTALLATION .)  

4. Tire house trim (See TIRE HOUSE TRIM REMOVAL/INSTALLATION .)  

5. Aeroboard (See AEROBOARD REMOVAL/INSTALLATION .)  

6. Front seat back bar garnish (See SEAT BACK BAR GARNISH 

REMOVAL/INSTALLATION .)  

2. Remove the back trim. (See BACK TRIM REMOVAL/INSTALLATION .)  

3. Remove the service hole cover. 

Fig. 20: Identifying Service Hole Cover 
Courtesy of MAZDA MOTORS CORP. 

5. Disconnect the quick release connector from the fuel pump unit. (See QUICK RELEASE 

CONNECTOR (FUEL SYSTEM) REMOVAL/INSTALLATION [LF] .)  

6. Disconnect the fuel pump unit connector.  

7. Remove in the order indicated in Fig. 21 . 

 

2008 Mazda MX-5 Miata Grand Touring 

2008 ENGINE Fuel System - MX-5 Miata