Fuel Injection Valve
When installing a fuel injection valve, always check the seats of both the nozzle and the precombustion chamber. The nozzle assembly should be only finger-tight on the body. It is important to maintain the nozzle retaining nut torque to 105 ± 5 lb. ft. (14.5 ± 0.7 mkg). EXCESSIVE TORQUE will damage the nozzle. LESS TORQUE will allow the nozzle to leak and may cause the nozzle case to bulge or split.
Fuel Injection Pump
Use an 8S4613 Wrench and 8S2244 Extractor to remove and install fuel injection pumps.
When removing fuel injection pumps, spacers and lifters the components should be kept together and marked so they can be installed in their respective locations.
While disassembling fuel injection pumps, exercise considerable care to prevent damage to the plunger surfaces. The barrel and the plunger are matched and are not interchangeable. Use extreme care when inserting the plunger into the bore of the barrel.
Fuel Injection Pump Installation
The installation of fuel injection pumps requires that the lifter be at a low point and the fuel rack be centered or at “zero” position. To center or “zero” the rack, install the 7S7113 Rack Setting Gauge and set it at .000 in., retract the speed limiter, and move the rack in “fuel on” direction until it contacts the gauge. To install the pump, sight down the pump and align notches in bonnet and barrel with slot in the pump gear segment. Slot is 180° from pump gear segment center tooth.
RACK SETTING GAUGE INSTALLED
1. 7S7113 Rack Setting Gauge. A. 9S240 Rack Positioning Tool Group can also be used.
Position the notches in bonnet and barrel to align with dowels in the housing. Install the pump. Keep a downward force (by hand) on the pump and install the bushing finger tight, until flush with top of housing. If the bushing cannot be assembled this far finger tight, remove the bushing and pump. The threads, on the bushing or in the housing, can be the restriction. Align the pump components and reinstall it. If the bushing installs correctly, tighten it to a torque of 150 ± 10 lb. ft. (20.7 ± 1.4 mkg). Overtightening the bushing can damage the housing or if the bushing is not tight enough, the pump will leak.
Total rack travel, approximately .800 in. (20.32 mm), will be reduced if the pump is installed one or more teeth off in either the “fuel on” or “fuel off” side of its gear segment. The only way to check for correct installation of pumps with engine stopped is to measure full rack travel with the entire governor removed, including piston and valve mechanism.
Fuel Injection Lines
Fuel from the fuel injection pumps is sent through the fuel injection lines to the fuel injection valves.
Each fuel injection line of an engine has a special design and must be installed in a certain location. When fuel injection lines are removed from an engine, put identification marks or tags on the fuel lines as they are removed, so they can be put in the correct location when they are installed.
TIGHTENING THE NUT OF A FUEL INJECTION LINE
1. 5P144 Fuel Line Socket.
The nuts that hold a fuel injection line to an injection valve and injection pump must be kept tight. Use a torque wrench and the 5P144 Fuel Line Socket (1) to tighten the fuel line nuts to 30 ± 5 lb. ft. (4.1 ± 0.7 mkg).
Fuel Bypass Valve
The fuel bypass valve should control fuel pressure to the fuel injection pump at full speed to a pressure of 25 to 32 psi (1.8 to 2.2 kg/cm2).