Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Injection pump, servicing: Notes
Only vehicles with engine code ALH
- Note rules of cleanliness. Refer to Rules of cleanliness
- Always replace sealing rings and O-rings
1 - Seal
- Always replace
2 - Connecting piece 25 Nm
- For supply line
- From fuel filter
3 - Injection pump
- With quantity adjuster
- With Fuel Temperature Sensor -G81-*, checking. Refer to Fuel Temperature Sensor, checking
- With Quantity Adjuster -N146-*, checking. Refer to Modulating Piston Displacement Sensor and quantity adjuster, checking
- With Modulating Piston Displacement Sensor -G149-*, checking. Refer to Modulating Piston Displacement Sensor and quantity adjuster, checking
4 - Fuel Cut-off Valve -N109-, 25 Nm
5 - Connecting piece
- For return line
6 - Return line
- To regulator valve/fuel filter
7 - 25 Nm
8 - Injection lines
- Tighten to 25 Nm
- Use 3035 ring spanner to remove and install
- Always replace two-piece wiring set completely
- Do not change bend shape
9 - Connecting piece, 45 Nm
- With pressure valve
10 - 25 Nm
11 - Fuel injector
- Removing and installing. Refer to Injectors, removing and installing
- Checking. Refer to Injectors, checking
- For cylinder 3 with needle lift sensor
- Check Needle Lift Sensor -G80-*. Refer to Needle lift sensor, checking
12 - 20 Nm
13 - Tension bracket
14 - Mounting bracket
15 - Copper washer
- Always replace
16 - 10 Nm
17 - Cold Start Injector -N108-*
- Checking. Refer to Cold Start Injector, checking
18 - Gasket
- Always replace
19 - Sieve
- Clean strainer if dirty
20 - Timing control cover
- Replace seal if leaking.
21 - Socket
- With nut
22 - Bracket
23 - 25 Nm
24 - Securing bolts of injection pump sprocket
- Note different versions and tightening torques. See Versions of securing bolts for injection pump sprocket
25 - Injection pump sprocket
- Note different versions (replacement part numbers). See Versions of securing bolts for injection pump sprocket
26 - Mounting nuts
- For hub
- Must not be loosened under any circumstances. Basic setting of the injection pump may be altered, this cannot be reset with normal workshop equipment
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.