Appendix
90
2. The idle speed
is unstable
1. There is air leak in the air intake pipeline
Check the air intake
pipeline for leak
2. The spark plug or ignition system has
failure.
Check the spark plug and
high-voltage cable.
3. The pressure of gas metering valve is too
low
Check the pressure
reducer solenoid valve.
4. The electronic throttle has failure
Check or replace the
electronic throttle valve.
3. The exhaust
pipe blasts
The blasting is mainly caused by the
secondary combustion of unburned gas in
exhaust pipe.
1. One or more cylinders do not work (for
example: ignition coil is broken; the wires in
ignition coils of some cylinders are
exchanged by mistake; the spark plug does
not work properly, etc.)
Check the spark plug
,
ignition coil and wiring
harness.
2. The natural gas supplied is too thick or
too thin (the pressure reducer works
improperly)
Check the oxygen sensor
and gas metering valve.
3. Overlarge phase difference in ignition
advance angle.
Check the ignition
advance angle by ignition
rob and the clearance
between phase sensors.
4. The engine is
under-powered
1. The manual valve on natural gas bottle is
not fully opened.
Check the gas bottle.
2. The gas pressure is too low.
Checking whether the
pressure reducer, gas
pipeline and gas filter are
normal.
3. The ignition system has failure.
Check the spark plug
、
ignition cable and ignition
coil
4. The pressure reducer is out of order.
Check the gas pressure.
5. Air intake system has failure
Check the air filter and air
intake system for blockage
and leak.