7. Remove the ignition coils. (See
IGNITION COIL REMOVAL/INSTALLATION [LF]
.)
8. Remove the spark plugs. (See
SPARK PLUG REMOVAL/INSTALLATION [LF]
.)
9. Connect a compression gauge into the spark plug hole.
10. Fully depress the accelerator pedal and crank the engine.
11. Note the maximum gauge reading.
12. Inspect each cylinder as above.
If the measured value is less than the limited value, or there is a cylinder whose compression value
varies from that of other cylinders by
196.1 kPa {2.0 kgf/cm
2
, 28.5 psi}
or more, add a small
amount of engine oil through the spark plug hole. Then measure the compression pressure and
perform the respective operations for the following cases.
If the compression increases, the piston, the piston rings, or cylinder wall may be worn and
overhaul is required.
If the compression stays low, a valve may be stuck or improperly seated and overhaul is
required.
If the compression in adjacent cylinders stays low, the cylinder head gasket may be damaged
or the cylinder head distorted and overhaul is required.
Compression
Standard: 1,720 kPa {17.5391 kgf/cm
2
, 249.465 psi} [300 rpm]
Minimum: 1,204 kPa {12.277 kgf/cm
2
, 174.58 psi} [300 rpm]
Maximum difference between cylinders: 196.1 kPa {2.0 kgf/cm
2
, 28.5 psi}
13. Disconnect the compression gauge.
14. Install the spark plugs. (See
SPARK PLUG REMOVAL/INSTALLATION [LF]
.)
15. Install the ignition coils. (See
IGNITION COIL REMOVAL/INSTALLATION [LF]
.)
16. Install the front suspension tower bar (joint). (See
FRONT SUSPENSION TOWER BAR
REMOVAL/INSTALLATION
.)
17. Install the fuel pump relay.
18. Complete the "AFTER SERVICE PRECAUTION". (See
AFTER SERVICE PRECAUTION [LF]
.)
TIMING CHAIN REMOVAL/INSTALLATION [LF]
WARNING:
Fuel vapor is hazardous. It can very easily ignite, causing serious
injury and damage. Always keep sparks and flames away from fuel.
Fuel line spills and leakage are dangerous. Fuel can ignite and
cause serious injures or death and damage. Fuel can also irritate
skin and eyes. To prevent this, always complete the "Fuel Line
Safety Procedure". (See BEFORE SERVICE PRECAUTION [LF] .)
2007 Mazda MX-5 Miata Sport
2007 ENGINE Mechanical - MX-5
Microsoft
Thursday, July 09, 2009 3:21:50 PM
Page 32
© 2005 Mitchell Repair Information Company, LLC.