Appendix
78
2. The idle speed
is unstable
1. There is air leak in the air intake pipeline
Check the air intake
pipeline
2. The spark plug or ignition system is in
fault
Check the spark plug and
high-pressure line.
3. The pressure of gas metering valve is
too low
Check whether the
pressure reducer solenoid
valve and gas pipeline are
smooth.
4. The electronic throttle is in fault
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.
Check whether the
pressure reducer, gas
pipeline and gas filter are
smooth.
3. The ignition system is in fault.
Check the spark plug
、
ignition cable and ignition
coil
4. The pressure reducer is out of order.
Check the gas pressure.
5. There is insufficient gas intake
Check the air filter and gas
intake system for blockage
and air leak.
