Leak Test (LEAK TEST)
The leak test checks for potential leaks in the control valve, high-pressure seals, and nozzle cap. Detecting and resolving leaks ensures proper injector functionality and prevents fuel loss.
Maximum Injection Quantity (VL)
This test measures the maximum fuel delivery:
- Too High: Leads to excessive smoke and high fuel consumption.
- Too Low: Causes poor acceleration and reduced engine power.
- Adjustment: Ensure individual injector deviations are within 6 mm³/HH. This is primarily adjusted using nozzle lift shims.
Medium-Speed/Emission Point Injection Quantity (TL/EM)
This validates injection characteristics:
- Too High: Causes excess smoke and emissions.
- Too Low: Results in weak acceleration.
- Adjustment: Includes nozzle spring shims, armature stroke, lift shims, and solenoid valve spring shims.
Idle Injection Quantity (LL)
This measures fuel delivery during idle:
- Too High: Leads to smoky idle and rough engine running.
- Too Low: Causes stalling and difficulty starting.
- Adjustment: Nozzle spring shims ensure uniformity within 2 mm³/HH.
Pre-Injection Quantity (VE)
This test determines the fuel delivered during pre-injection:
- Too High: Leads to engine knocking and smoke.
- Too Low: Results in increased noise, poor starting, and weak acceleration.
- Adjustment: Solenoid valve spring shims help maintain uniformity within 0.5 mm³/HH.
