Troubleshooting for Mechanical Pump of Diesel Engine
Posted: 2014-11-10 19:08:41 Hits: 1633
1. Fuel injection pump abrasion lead to diesel enter into oil
Fault: engine oil level rises significantly with the smell of diesel oil. What is serious is that oil discharges from oil filer or ventholes. As for the piston fuel supply pump, diesel oil has only two ways to enter into the engine oil: diesel oil can enter into the lubricating oil inside lower chamber of fuel injection pump directly from backlash of the roller body in fuel delivery pump; the other way is that abrasion of plunger and barrel assembly of wheel cylinder of fuel injection pump overruns, causing the inner leakage of wheel cylinder (may have great influence on normal start of engine), diesel fuel having inner leakage flows into the lubricating oil of lower chamber .
Solution: Open the side cover of fuel injection pump and start the engine. If abrasion of plunger and barrel assembly of wheel cylinder of fuel injection pump overruns, it means that plunger and barrel assembly needs to be changed and fuel injection pump also needs to be verified on test bed. Remove the feed pump (don’t remove the connecting tube). Pour pump oil of hand oil pump. If diesel oil leaks out from backlash of wheel of fuel delivery pump, it means that fuel delivery pump has obstacles. Also can remove connecting tubes and tighten the hand pump. Plug up the outlet of fuel delivery pump, introducing 0.4MPa of gas from its oil inlet. If gas leaks from backlash of wheel, it means that fuel delivery pump has obstacles and needs to be changed.
2. Oil leaks from connection of high pressure oil tube at outlet of fuel injection pump
Reasons: the connection between concave type oil outlet of fuel injection pump and round convex type high pressure oil tube causes untight seal and leakage for abrasion. Stack spacers up the concave type connection at outlet of fuel injection pump outlet. Every manufacturer has spacers which can be presented with pump. Using the same method can solve the leakage of connection between injector and high pressure tube. Practice is effective.
3. The axle of fuel injection pump breaks off
If the four fin thread bolts are not tightened tightly, when engine working, dry grinding occurs between loosening pump and pump seat, resulting in gap. The time is longer, the gas is larger. Installation site of fuel injection pump displaces. Decentraction of fuel injection pump and transmission shaft makes shaft broke.
Solution: Use copper having proper thickness copper as cushion. Pad it between pump and pump seat to eliminate the clearance. When refitting fuel injection pump, the thread hole should be cleaned. Then tighten 4 pieces of retaining bolt to specified torque, and check the coaxiality of shaft of fuel injection pump and transmission shaft. It needs to be readjusted if it is not conform to the standard. It’s suggested that remove the pump seat together when removing the injection pump.
Fault: engine oil level rises significantly with the smell of diesel oil. What is serious is that oil discharges from oil filer or ventholes. As for the piston fuel supply pump, diesel oil has only two ways to enter into the engine oil: diesel oil can enter into the lubricating oil inside lower chamber of fuel injection pump directly from backlash of the roller body in fuel delivery pump; the other way is that abrasion of plunger and barrel assembly of wheel cylinder of fuel injection pump overruns, causing the inner leakage of wheel cylinder (may have great influence on normal start of engine), diesel fuel having inner leakage flows into the lubricating oil of lower chamber .
Solution: Open the side cover of fuel injection pump and start the engine. If abrasion of plunger and barrel assembly of wheel cylinder of fuel injection pump overruns, it means that plunger and barrel assembly needs to be changed and fuel injection pump also needs to be verified on test bed. Remove the feed pump (don’t remove the connecting tube). Pour pump oil of hand oil pump. If diesel oil leaks out from backlash of wheel of fuel delivery pump, it means that fuel delivery pump has obstacles. Also can remove connecting tubes and tighten the hand pump. Plug up the outlet of fuel delivery pump, introducing 0.4MPa of gas from its oil inlet. If gas leaks from backlash of wheel, it means that fuel delivery pump has obstacles and needs to be changed.
2. Oil leaks from connection of high pressure oil tube at outlet of fuel injection pump
Reasons: the connection between concave type oil outlet of fuel injection pump and round convex type high pressure oil tube causes untight seal and leakage for abrasion. Stack spacers up the concave type connection at outlet of fuel injection pump outlet. Every manufacturer has spacers which can be presented with pump. Using the same method can solve the leakage of connection between injector and high pressure tube. Practice is effective.
3. The axle of fuel injection pump breaks off
If the four fin thread bolts are not tightened tightly, when engine working, dry grinding occurs between loosening pump and pump seat, resulting in gap. The time is longer, the gas is larger. Installation site of fuel injection pump displaces. Decentraction of fuel injection pump and transmission shaft makes shaft broke.
Solution: Use copper having proper thickness copper as cushion. Pad it between pump and pump seat to eliminate the clearance. When refitting fuel injection pump, the thread hole should be cleaned. Then tighten 4 pieces of retaining bolt to specified torque, and check the coaxiality of shaft of fuel injection pump and transmission shaft. It needs to be readjusted if it is not conform to the standard. It’s suggested that remove the pump seat together when removing the injection pump.
