Start of Injection, Dynamically Checking and Adjusting
Start of injection, dynamically checking and adjusting:Note: Dynamically checking and correcting start of injection is only possible using "Basic Setting" scan tool function 04.
Note:
Start of injection must always be checked and adjusted after:
- Replacing the toothed belt
- Loosening the Diesel injection pump mounting bolts
- Loosening the toothed belt sprockets
Special tools, testers and auxiliary items:
- VAG1551 or VAG1552 Scan Tool (ST)
- VAG1551/3 adapter cable
- 3035 injector line wrench
- Torque wrench (VAG1331 or equivalent) - 5 to 50 Nm (approx. 40 ft lb).
Checking and adjustment conditions:
- Mechanical engine basic settings OK
- Toothed belt tension OK
Checking:
1. Connect VAG1551 or VAG1552 scan tool.
2. Start engine and let idle.
3. Press buttons -0- and -1- to insert the "Engine Electronics" address word 01.
Scan Tool Display:
The above image will now be indicated on display:
4. Press buttons -0-and -4-to select "Basic Setting" function 04.
5. Press -Q- button to confirm input.
Scan Tool Display:
The above image will now be indicated on display:
6. Press -0-button three times to input display group no.0(000).
7 Press -Q- button to confirm input.
Scan Tool Display:
Indicated on display (1-10 display fields)
Note: The start of injection value in display field 2 varies depending on the fuel temperature value in display field 9.
Start Of Injection VS Fuel Temperature:
A - Display field 2--Start of injection value.
B - Display field 9--Fuel temperature value.
C - Specified range for start of injection (depending on fuel temperature).
Example: The fuel temperature value "B" in display field 9 (e.g. 90) corresponds to the start of injection value "A" in display field 2, which should fall within the range "C" between 34 and 73.
Note:
- If, when checking the start of injection, the results fall within zone -C-, no adjustment is required.
- After repairs e.g. removing and installing Diesel injection pump, set the start of injection to the mean value (dashed line) of the specified zone -C-.
- If the start of injection is too far advanced, adjust by turning the injection pump in the direction of engine rotation.
- If start of injection is too far retarded, adjust by turning the injection pump against the direction of engine rotation.
8. Loosen Diesel injection pump mounting bolts approx. 1 turn, but leave easiest-to-reach bolt until last.
9. Hold injection pump under tension by hand, in direction to be adjusted.
10. Carefully loosen last mounting bolt until injection pump can just be turned slightly, then re-tighten last mounting bolt.
11. Check values in scan tool display field 2; if necessary adjust again until display equals mean value for specified range -C-.
12. Tighten injection pump mounting bolts. Tightening torque: 25 Nm (18 ft lb).
13. Check start of injection again.
14. Press the next arrow "-->" button.
15. Press buttons -0- and -6-to select "End Output" function 06.
16. Press -Q- button to confirm input.
Note: Loosen and re-tighten the injector lines on the injection pump (25 Nm, 78 ft lb) after it has been dynamically adjusted. This relieves any line strain and prevents damage due to vibration.
17. Using Scan Tool, Check and erase DTC memory. Testing and Inspection
18. Using Scan Tool, Re-create readiness code as shown in Computers and Controls, Testing and Inspection Procedures.