SkyTrak 6036 Service Manual - Manual (Page 111)

Section 8A Perkins Engine
Model 6036/6036T S/N 9B0500 thru 14833 8A-19
8A.13.7 Fuel Injection Pump
The fuel injection pump is a distributor type pump
with a mechanical flyweight type governor. The
pump is flange mounted and is driven from the
engine timing case.
IMPORTANT: Instructions and specifications in
the Perkins Engine Manuals are required for fuel
injection pump maintenance and servicing Do not
remove pump from engine unless you have this
information which is essential to correct fuel
injection pump installation.
8A.13.8 Fuel Injectors
Fuel injectors should be taken out for examination
at regular intervals.
When replacing fuel injectors in the cylinder head
it is essential that a new, correct type copper
washer is installed between the nozzle cap and
cylinder head.
Earlier engines have a one piece collar-type dust
seal; later engines have an improved two-piece
arrangement which consists of a soft rubber
sealing ring or sleeve and a rigid plastic spacer
which presses down onto the rubber sealing ring.
The rubber sealing ring is always installed below
the rigid spacer.
Tighten securing nuts evenly to 14 lb-ft (19 Nm).
a. How to Locate Faulty Fuel injector(s)
A faulty fuel injector can cause:
• Misfiring
• Knocking in one (or more) cylinders
• Engine overheating
• Loss of power
• Smoky exhaust (black)
• Increased fuel consumption
The particular faulty fuel injector or fuel injectors
may be determined by releasing the pipe union nut
on each fuel injector in turn, with the engine
running at a fast “tick-over”. If after slackening a
pipe union nut the engine revolutions remain
constant, this denotes a faulty fuel injector.
To test the fuel injector:
1. Remove the fuel injector from the cylinder
head.
2. Invert the fuel injector with the nozzle facing
outwards and then retighten the unions.
3. Slacken the unions of the other fuel injector
pipes (to avoid the possibility of engine
starting).
4. Use the starter to turn the engine over until
fuel sprays from the nozzle. Examine the
shape of the spray. If the spray is unduly
“wet” or “streaky” or obviously to one side, or if
the nozzle “dribbles” it may only be necessary
to probe the nozzle holes to remove carbon.
IMPORTANT: Do not attempt to adjust injection
pressure without a testing pump and pressure
gauge. It is impossible to adjust the setting of fuel
injectors with any degree of accuracy without the
proper equipment.
A perfect fuel injector, when tested by pumping
fuel through it in the open air gives a short “ping-
ing” sound as the fuel emerges from the holes.
After the fuel injector has been in service for some
time, the “pinging” changes to a crackling sound.
It is not until the fuel injector sounds “dead” that its
condition is likely to affect the running of the
engine.
b. Fuel Injector Identification
Currently, the fuel injector code is stamped on the
fuel injector body.
c. How to Replace a Fuel Injector
1. Remove the fuel leak off pipe.
2. Remove the high pressure pipe union nuts
from the fuel injector and fuel injection pump
and release the pipe.
3. Remove the fuel injector flange nuts and
remove the fuel injector and seat washer.
4. Put new fuel injector with new seat washer, in
position. Be sure fuel injector is not tilted and
tighten the flange nuts evenly by small
amounts to 14 lb-ft (19 Nm).
5. Connect high pressure fuel pipe and tighten
nut to 15 lb-ft (20 Nm).
6. Connect the leak off pipe.
7. Run the engine and check for fuel and air
leakage.
8. Bleed the fuel system by following the proce-
dures in paragraph 8A.7.3.
Caution
Be careful to keep hands and face from coming
in contact with spray as it will cause fuel oil to
penetrate the skin.