FUEL SYSTEM
3TNV88F Service Manual
7-21
Checking and Adjusting Fuel Injection Timing
The FIR number is determined by the complete
engine model number. The engine model
number is located on the engine nameplate
.
Figure 7-33
• Find the engine model number in the FIR chart.
Locate and record the FIR number (For
example the FIR number is 4).
• Insert the numbers you have recorded into the
following equation:
(Fuel injection pump timing index number × 2) +
FIR number = FIT° (Fuel injection timing in
degrees)
■
(6.8 × 2) = 13.6 + 4 = 17.6° fuel injection
timing
• Record the calculated fuel injection timing
specification.
Checking Fuel Injection Timing
Note: Some fuel may drain from the fuel injection
pump during this process. Make provisions
to contain any such spillage.
1. Turn off the fuel valve in the fuel supply hose
and the fuel return hose.
2. Clamp shut the fuel injection pump fuel return
hose leading to fuel filter
.
Figure 7-34
NOTICE
Clean the top of the fuel injection pump to prevent
any contamination when the fuel injection pump
plunger plug is removed.
3. Remove the forward fuel injection pump plunger
plug
(Figure 7-34, (2))
on the top of the fuel
injection pump.
4. Install a dial indicator adapter and clamp into
the pump plunger opening.
Note: Use the YANMAR Part No. 158090-
51831 M14 adapter for the MP2 fuel
injection pumps and YANMAR Part No.
23000-013000 plunger adapter clamp
(Figure 7-35, (1)).
M O D E L
D I S P L A C E M E N T
E N G I N E N O .
MADE IN JAPAN
043923-00X00
1
2
046365-00X00
3TNV88F_SVM_A4.book 21 ページ 2012年7月26日 木曜日 午後6時4分