106471-4050 ZEXEL 9 400 610 821 BOSCH INJECTION-PUMP ASSEMBLY 9400610821 1064714050

Do not use more than 55 kPa (8 psi) of air pressure in the fuel tank or damage to the tank may result.
Check for leaks at the connections between the fuel tank and the fuel transfer pump. If leaks are found, tighten the connections or replace the lines. If there are no visual leaks, remove the fuel supply line from the tank and connect it to an outside fuel supply. If this corrects the problem, the suction line (standpipe) inside the fuel tank has a leak.C. Poor Quality Fuel Remove a small amount of fuel from the tank and check for water or other contamination in the fuel. See Special Instruction, Form No. SEHS7067 for complete information on fuel recommendations for Caterpillar diesel engines. If there is water in the fuel, remove the fuel until it is free of water. Fill with good quality fuel. Change the fuel filter and prime the system using the fuel priming pump. If there is water in the fuel, use an outside source of good quality fuel, prime and start the engine. If the engine starts easily, remove all the fuel from the fuel tank and fill with good quality fuel. Prime the fuel system if necessary.D. Low Fuel Pressure Change the fuel filter. If the pressure remains low, check the by-pass valve in the fuel transfer pump and the fuel pressure regulating valve in the fuel manifold adapter. Debris in the system can cause the valves to remain in the open position.E. Fuel Injection Timing Out Of Calibration Check the fuel injection timing calibration and make necessary calibrations. See Engine Test Procedure Number P-301 in Electronic Troubleshooting, 3176 Vehicular Diesel Engine, Form No. SENR5137.F. Valve Adjustment Not Correct Check and make necessary adjustments. See the topic, Valve Clearance Setting, in 3176 Vehicular Diesel Engine Systems Operation And Testing and Adjusting, Form No. SENR4964. Intake valve clearance is 0.38 mm (.015 in), and exhaust valve clearance is 0.64 mm (.025 in). Also check for bent or broken push rod or other valve train parts.G. Defective Unit Injector(s) Testing of the injectors must be done off of the engine. Use the 1U6661 Pop (Injector) Tester Group with a 1U6663 Injector Holding Block, and a 1U6665 Power Supply, to test the injectors. For the test procedure refer to Special Instruction, Form No. SEHS8867, Using The 1U6661 Pop (Injector) Tester. For test specifications refer to Special Instruction, Form No. SEHS8804, Unit Injector Test Specifications for 1.7 Liter Engines. Inspect and repair as necessary the sealing surface (seat) of the injector sleeve in the cylinder head when removing and installing an injector. The injector sealing surface (seat) must be free of scratches or evidence of combustion products. If it is necessary to rework (ream) or replace the sleeve use 4C4054 Tool Group and refer to Special Instruction, Form No. SEHS9246, Using The 4C4054 Unit Injector Sleeve Replacement Tool Group.H. Low CompressionSee the topic, Misfiring and Running Rough in this publication.8. Possible Causes-Engine Will Not StartA. No