6.1.5. Diagnostics and troubleshooting - 150 - MAINTENANCE OF MAJOR COMPONENTS Complaints Possible causes Corrections 1.
Engine won’t start 1) Fuel not being pumped out from feed pump 2) Fuel not being injected from injection pump 3) Fuel injection timing incorrect 4) Injection nozzles inoperative ®1 Fuel pipes clogged or air into pipe fine ®2 Feed pump valve defective ®3 Feed pump piston or Push rod sticking Correct Replace Disassemble, correct ®1 Fuel filter element restricted ®2 Air in fuel filter or injection pump ®3 Plunger and/or delivery valve sticking or defective Clean Bleed Disassemble, correct ®1 Injection pump not properly installed on pump bracket ®2 Injection pump tappet incorrectly adjusted ®3 Cams on cam shaft worn excessively Check, correct Check, correct Replace ®1 Needle valves sticking ®2 Fuel leaking past clearance between nozzle and needle valve ®3 Injection pressure incorrect Correct or replace Correct or replace Adjust 2.
Engine starts but stalls immediately ®1 Pipe from feed pump to injection pump clogged or filter clogged ®2 Air in fuel ®3 Feed pump delivery insufficient ®4 Fuel delivery insufficient due to clogging of fuel tank air breather Clean Bleed Disassemble, correct Replace breather 3. Engine lacks power ®1 Plunger worn excessively ®2 Injection timing incorrect ®3 Delivery valves defective ®4 Nozzle leaks excessively ®5 Nozzle not working normally Replace Adjust Replace Correct or replace Disassemble, correct 4. Engine knocking ®1 Injection timing too fast ®2 Nozzle injection pressure too high ®3 Nozzles not working normally Adjust Adjust Disassemble, correct 5.
Engine knocks seriously producing excessive exhaust smoke ®1 Injection timing incorrect ®2 Nozzle Injection Pressure too low ®3 Nozzle spring broken ®4 Nozzles not working normally ®5 Plungers worn excessively ®6 Delivery valves seat defective ®7 Supply of fuel excessively Adjust Adjust Replace Replace Adjust Replace Check feed pump