Geely EC718 2009 Workshop Manual page 600

2-518 Ignition System JL4G18-D Engine
2.10.2 Description and Operation
2.10.2.1 Description and Operation
This vehicle uses DLI ignition system igniting two cylinders at
the same time. The ignition voltage is sent directly from the
ignition coil to the Spark Plug. Main system components are
ECM, two ignition coils, high voltage damping line, Spark Plug,
crankshaft position sensor, camshaft position sensor, knock
sensor etc.. This Ignition system is known as the direct ignition
type. Cylinder No.1 is paired with Cylinder No.4 and Cylinder
No.2 is paired with Cylinder No.3. When ECM triggers the
ignition coil to ignite, spark occurs in both cylinders at the same
time. At this time one cylinder is in compression stroke and the
other is in exhaust stroke. For the cylinder in the exhaust
stroke, because the cylinder pressure is low, the temperature
is high, the spark plug only requires minimal energy to break
ignition voltage gap. It is an invalid ignition, the remaining
energy is used by the spark plug in the compression stroke
cylinder.
As a result of using DLI Ignition System, ECM controls the best
ignition timing based on a variety of load conditions, so that the
engine output power, acceleration, economy and emission
performance have reached the ideal situations. The ignition
system voltage does not decrease as the speed increases. In
the absence of mechanical components, there is mechanical
error.
The ignition coil can not be repaired and it must be replaced as
an assembly.
EC718/EC718RV EC715/EC715RV 10/2009