Maintenance Manual for J2 Sedan
Mechanical Part of Engine
64
XI. Cylinder head
1. On-vehicle Maintenance
1) Inspect the cylinder pressure:
①
Thoroughly warm up the engine and then stop it.
②
Release the fuel pressure. See “Release of Fuel Pressure”.
③
Disconnect the fuse of fuel pump, otherwise the fuel may be sprayed out during measurement.
④
Use special ignition coil and spark plug removal tool. See "Ignition Coil" and the "Spark Plug."
⑤
Dismantle engine trimming cover. See “Intake manifold”.
⑥
Install a cylinder pressure gauge (with joint) on the spark plug hole.
⑦
Push the accelerator pedal to the end, then turn the ignition switch to the “START” position to start
the engine. After the instrument finger appears stable, read compression pressure and engine speed.
Perform these steps to check other cylinders.
■
Standard pressure: 1200±100 kPa
■
Tolerable pressure difference between cylinders:
≤
98kPa
Attention:
■
It is required to obtain the specified engine speed always by the battery which is fully
charged.
■
Inspect valve clearance and other relevant parts (such as valve, valve seat, piston, piston ring,
cylinder bore, cylinder head and gasket) if the compression pressure is less than the minimum
value. Repeat measurement of compression pressure after the check.
If the pressures in some cylinders are low, add some engine oil to the spark plug holes of such
cylinders and then inspect again.
■
The piston ring may be worn or damaged if the cylinder pressure rises after the engine oil is
added. Check the piston ring and replace if necessary.
■
The valve may have faulty if the compression pressure is still low after the adding of engine
oil. Check whether the valve is damaged. Replace the damaged valve or valve seat.
■
The cylinder gasket must be leaky if the compression pressures in two neighboring cylinders
are low and even keep low after adding engine oil. Replace cylinder gasket.
⑧
After inspection, remount the dismounted parts.
⑨
Start engine, confirm that the engine runs smoothly.
