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EUI operation and adjustments. Filling of chamber by lift pump pressure. Cam forces plunger down to raise pressure in chambers. Solenoid activation + Cam forcing plunger down to create high pressure and nozzle opening.
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EUI operation and adjustments Filling of chamber by lift pump pressure Cam forces plunger down to raise pressure in chambers Solenoid activation + Cam forcing plunger down to create high pressure and nozzle opening Solenoid deactivated + Cam forcing plunger down to create pressure drop and nozzle closing • Fuel delivery and timing is dependant on: • The duration and point of time that the solenoid is activated, (controlled by ECU on engine or Ocres on test-bench) not adjustable. • The reaction time of the solenoid electrically to magnetic strength, (controlled by the electrical and magnet properties of the solenoid) not adjustable, fit new solenoid. • The reaction time of the valve closing against spring pressure, (controlled by the holding spring and adjustment shim) adjusted by changing shim thickness. • The pressure raised by the plunger, (controlled by the sealing properties of the plunger to the bore) not adjustable. • The reaction time of the nozzle opening against spring pressure (controlled by the return spring and adjustment shim) adjusted by changing shim thickness. • The flow characteristic of the nozzle; Low, Medium, High (grading determined by manufacturing tolerances), compensated for by changing items 3, 5 or both.
EUI operation and adjustments • Adjustments need to take all dependencies into consideration and any adjustments there of? • Solenoid shim adjustment • To overcome a slow solenoid activation • To adjust fuel delivery • To overcome manufacturing tolerances in nozzle flow (L, M, H) • To adjust injection timing point (adjust delay time) • Nozzle shim adjustment • To adjust fuel delivery • To overcome manufacturing tolerances in nozzle flow (L, M, H)
EUI operation and adjustments • Adjustments will have the following effects? • Solenoid shim adjustment (within tolerances) • Increasing the shim thickness will:- • Make the response time longer (0.02mm = + 8µs) • Make the fuel delivery reduce (0.02mm = -1mm3/St) • Reducing the shim thickness will:- • Make the response time shorter (0.02mm = - 8µs) • Make the fuel delivery increase (0.02mm = +1mm3/St) • Nozzle shim adjustment (within tolerances) • Increasing the shim thickness will:- • Make the fuel delivery reduce (adjustment for high flow nozzle, set on upper limit) • Reducing the shim thickness will:- • Make the fuel delivery increase (adjustment for low flow nozzle, set on lower limit)