Great Wall GW491QE, Service Manual

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GI-10
3.engine is slack.
Cause of failure Methods of elimination
1 E ngine is under a bad compression condition.
1 Valve is leaking air.
2 Hydraulic retaining column not
working well.
3 Valve spring is with an insufficient
force or even broken.
4 Pad of cylinder is leaking air.
5 Piston ring is stuck or broken.
6 Piston or cylinder is much abraded.
2 Failure in ignition system
Spark plug not working well.
3 Petrol supply is blocked.
1 Petrol tank has contaminant deposits.
2 Petrol pipe is blocked.
3 Petrol filter is blocked.
4 Petrol pump not working well.
5 A ir exists in the fuel system.
4 Petrol not conforming to the specification.
5 Intake manifold pipe is leaking air.
6 A ir entering the air pipe is insufficient.
1 A ir filter is blocked.
2 Choke valve has not been opened
completely.
7. E ngine too hot.
1
1 A brade the valve.
2 Check or change or wash the hydraulic tappet
.
3 Change the valve spring.
4 Change the cylinder pad.
5 Change the piston ring.
6 R epair or change relevant spare parts.
2 Clean, adjust or change the spark plug.
3
1 Clean or change the oil tank.
2 Clean the oil pipe or make it through.
3 Change the petrol filter.
4 R epair or change petrol pump
5 Check and tighten each joint.
4 Make it subject to technical specifications.
5 Check the intake manifold pipe and gasket.
6
1 Wash the cover, and clean the filtration core by
purging.
2 R epair and adjust its control mechanism.
7 R efer to the “methods of elimination” in case
of failure “ engine too hot” .
4.Engine is backfired or deflagrated.
Cause of failure Methods of elimination
1 Failure in ignition system
1 Joint on the ignition line is loose.
2 Spark plug not working well.
3 T he heat characteristics of spark plug
are inappropriate.
2 Inappropriate content of mixed gas
1 Petrol supply is blocked.
3 Failure in the valve mechanism
1 Valve is stuck or leaking air.
2 T he valve hydraulic retaining column
not working well.
3 Valve spring is with insufficient
strength.
4 T he cover of cylinder under a bad condition
1 Combustion chamber has carbon
deposit.
2 T he cover of cylinder is over hot or the
cooling is insufficient.
3 T he cover of cylinder is damaged.
5. T he high-tension resistance line is
misconnected or damaged.
1
1 Check and tighten each joint.
2 Wash, adjust or change the spark plug.
3 R eplace with spark plug having appropriate heat
characteristics.
2
1 R efer to article 3 in the “engine slack”.
3
1 A brade or change the valve.
2 Change or wash the hydraulic retaining
column.
3 Change the valve spring.
4
1 Clear away the carbon deposit.
2 Clear air away from the cooling water sleeve.
3 Change the cylinder head
5 Correct or change it.
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