FUEL SYSTEM7-30 TNV DI Service ManualChecking and Adjusting Fuel Injection Timing16. Prime the fuel system. See Priming the FuelSystem on page 4-15.17. Operate the engine and check for fuel andcoolant leaks.CHECKING AND ADJUSTINGFUEL INJECTION TIMINGDetermining the Fuel Injection TimingSpecification1. Locate and record the fuel injection pumptiming index number (Figure 7-37, (1)) stampedinto the boss on the engine side of the fuelinjection pump housing (Figure 7-36, (1)). Treatthis number as though there is a decimal pointbetween the two digits. i.e. 68 = 6.8Figure 7-36Figure 7-372. Using the FIR number for the engine beingserviced use the Fuel Injection Reference (FIR)Chart under “FIE Specs” on the YanmarDistributor Website(http://distributor.yanmar.co.jp).The FIR number is determined by the completeengine model number. The engine modelnumber is located on the engine nameplate(Figure 7-38).Figure 7-38EXAMPLE: The following example is for an enginemodel 3TNV82A-DSA.• Find the engine model number in the FIR chart.Locate and record the FIR number (The FIRnumber for this engine is 4).• Insert the numbers you have recorded into thefollowing equation:(Fuel Injection Pump Timing Index Number X 2)+ FIR Number = FIT° (Fuel injection Timing inDegrees)(6.8 X 2) = 13.6 + 4 = 17.6° Fuel injectionTiming• Record the calculated fuel injection timingspecification.0000040B(1)0002047(1)0003852
