105488-1872 ZEXEL 9 420 612 120 BOSCH GOVERNOR 9420612120 1054881872

Primary Engine Test For High Fuel Consumption 1. Fuel consumption records must be available before the high fuel consumption complaint can be verified. If symptoms indicate low power, then the low power test should be conducted first, because it could be the cause of the fuel consumption problem. This Primary Engine Test for High Fuel Consumption is the same as the Primary Engine Test for Low Power.2. Visually inspect the fuel system from the fuel tank to the fuel injection lines to see if there are any indications of fuel leaks. Tighten any loose connections found and, if necessary, replace lines that can not be repaired.3. Check the crankcase oil level and the coolant level of the radiator. Remove the boost air line from the AFRC (air-fuel ratio control) during the Primary Engine Test. This will prevent the AFRC from becoming pneumatically activated during the checks. If activated, the AFRC could give an indication of a problem when there is none.4. A slightly lower rpm (15 rpm below low limit) should be expected for the engine in vehicle than the rpm shown in the RACK SETTING INFORMATION. This is caused by the parasitic loads of the engine accessories involved.5. With the engine running, the throttle must have enough travel for the governor control lever to break over (go past the normal governor stop for high idle position) a small amount when the throttle pedal is fully depressed. If full travel is not available, disconnect throttle linkage from governor lever. With throttle linkage disconnected, full travel of governor lever will indicate linkage problems, and the linkage will have to be adjusted. Limited travel of the governor lever will indicate a problem within the governor.6. Only a mechanic with the correct training should change the high idle setting. The procedure is given in this Service Manual under the subject GOVERNOR ADJUSTMENTS.7. If high idle rpm can not be made correct with the high idle adjustment screw, there is a problem inside the governor. Disassemble the governor and check for damaged parts or wrong parts installed in the governor. Some common problems are worn bushings, worn spring seat, or a broken or wrong governor spring.8. Before 8S4627 Circuit Tester is installed, be sure to test the light for correct operation. Test light must come on when the clip of the wire is placed against the probe of the light (replace batteries or bulb if light does not come on). If light comes on and stays on when attached to governor, the insulation is bad or installed wrong in torque spring group or brass terminal. This must be corrected before test is performed.9. With the continuity light installed, quickly push accelerator pedal all the way to the floor. If the fuel rack and governor functions properly, the continuity light will come on during this free acceleration until high idle is maintained. If the light comes on, this is an indication that the mechanical movement of the governor and fuel injection pump parts