- Check compression pressure.
(a) Warm up engine.
(b) Remove ignition coil.
(c) Remove spark plug.
(d) Check cylinder compression pressure.
(1) Install cylinder compression pressure gauge on spark plug hole.
(2) Wide open throttle.
(3) Measure the pressure during crankshaft rotating.
Notes:
Ensure to use fully charged battery to make the rotating speed of engine reach or exceed 250rpm.
When measuring other items, please repeat steps (1) to (3).
Finish the measurement as soon as possible.
Compression pressure: 1080kPa
Min pressure: 1000kPa
Difference among cylinders: 100kPa
(4) If the compression pressure of one or more cylinders is too low, inject a small amount of engine oil
from spark plug hole into the cylinder with low pressure, and repeat steps (1) to (3) to check
pressure.
If the pressure increases after engine oil is injected, the piston ring of this cylinder or the
cylinder has been worn or scratched.
If the pressure is still too low, the valve may be stuck or not fully closed, or the cylinder head
gasket leaks.
- Check CO/HC.
(a) Start engine.
(b) Keep the rotating speed of engine at 2500rpm for about 180 seconds.
(c) When the engine is idle running, insert the test bar of CO/HC gauge into exhaust pipe at least 40cm.
(d) Immediately check idle speed and CO/HC concentration at 2500rpm.
Hints:
Finish test within 3 minutes.
Perform the test under 2 analog states (idle speed and 2500rpm) according to measuring meth-
ods and sequences specified by Emission Regulations.
(e) If CO/HC concentration is not within specified value, perform trouble shooting according to the
following sequences.
(1) Check the function of oxygen sensor.
(2) See possible failure causes listed in the table below, and repair and correct if necessary.
Engine mechanism - Engine assembly
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