Toro GROUNDSMASTER 345 - Manual (Page 31)

TORO GM 325-D Mitsubishi K3D Diesel Engine
Notes
________________________________________________________________________________________________________________
________________________________________________________________________________________________________________
________________________________________________________________________________________________________________
________________________________________________________________________________________________________________
________________________________________________________________________________________________________________
________________________________________________________________________________________________________________
________________________________________________________________________________________________________________
________________________________________________________________________________________________________________
________________________________________________________________________________________________________________
29
Injection Nozzles.
The diesel engine requires that the fuel be sprayed into the combustion chamber, at a precise point in the
compression stroke. The point at which this fuel injection occurs is the injection timing. If the nozzle is defective,
damaged, or adjusted incorrectly, the injection timing can be affected. This can cause hard starting, low power
output, excessive smoke or engine knocking.
IMPORTANT: Always use fresh filtered fuel in the nozzle tester. Use of dirty fuel can damage the
precision parts of the injector nozzle.
Injection nozzle tests:
The nozzle tester forces fuel from the nozzle under extremely high pressure.
Always point the nozzle away from your self and any other personnel.
To prevent possible injury always wear safety glasses.
1. Pressure test.
The injection nozzle is connected to the nozzle tester and the nozzle opening (Cracking) pressure is
measured. The pressure at which the injection nozzle opens has a direct effect on the injection timing and
the fuel spray pattern.
•
Minimum opening pressure 120 kg/cm² (1700 psi).
Maximum opening pressure 130 kg/cm² (1850 psi).
•
Nozzle opening pressure can be adjust by adding or removing shims.
2. Chatter Test.
With the nozzle connected to the nozzle tester, pump the tester slowly, the nozzle will open and close rapidly
(Chatter).
•
The chatter test checks the ability of the nozzle to open and close at a high rate of speed.
•
A nozzle that does not chatter, may be the result of binding or a bent nozzle.