Troubles Diagnosis - Sym ATTILA RS-21 EFi 150 Service Manual

1. General Information/Trouble Diagnosis

Troubles Diagnosis

A. Engine hard to start or can not be started
Check and adjustment
Loosen carburetor drain bolt to
check if there is gasoline
inside the carburetor
Fuel supplied to fuel
injector sufficient
Remove spark plug, install
it into spark plug cap, and
perform a spark test
against engine ground.
Check if spark.
Perform cylinder
compression pressure
test.
¬ â ¤ Õ
cylinder compression
pressure normal
Re-start by following the
starting procedures.
No ignition
Remove the spark plug
again and check it.
Dry spark plug
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This chapter Contents
Fault condition
No fuel is supplied to
fuel injector
Weak spark, no spark at
all.
Low compression
pressure or no pressure.
There are some signs of
ignition, nut engine can
not be started.
Wet spark plug
Probable causes
1. No fuel in fuel tank
2. Check if the pipes, fuel tank to fuel
injector and intake vacuum, are clogged.
3. Malfunction of fuel pump relay or poor
wire connection
4. Lines in fuel tank evaporation system
clogged
5. Malfunction of fuel pump
6. Fuel filter clogged
1. Malfunction of spark plug
2. Spark plug foul
3. Malfunction of ECU
4. Malfunction of AC generator
5. Ignition coil is in open or short circuit
6. Ignition coil leads open or short circuit
7. Malfunction of main switch
1. Piston ring seized
2. Malfunction of cylinder valves
3. Worn cylinder and piston ring
4. Cylinder gasket leak
5. Leak in compression parts
1. Malfunction of throttle valve operation
2. Air sucked into intake manifold
3. Incorrect ignition timing
1. Dirt or clogged fuel injector
2. Malfunction of throttle valve operation
3. Throttle valve opening too wide