Injection Pump - Checking/Adjusting
86VW4Applies To
GOLF DIESEL,
JETTA DIESEL
1986
Group
23
Subject
Diesel Injection System
Part Identifier NA
Key Points
Injection pump, checking/adjusting
A241
Number
86-01
May 1, 1986
The Diesel Injection Pump adjustment values have been changed. The change ensures that NOx limits can be more easily maintained..
Injection timing, checking and adjusting
Requirements
^ drive belt tension OK
^ cold start cable must not be pulled in (actuation lever on injection pump in a neutral position)
^ engine adjusted so that cylinder number 1 is at TDC
With engine installed:
- turn crankshaft until the TDC marking on the flywheel and the boss on bell housing align with the markings on the injection pump sprocket and mounting plate.
With engine removed:
- adjusting with tool:
standard transmission: 5.0 mm automatic transmission: 85.0 mm
- left notch in the scale (arrow A) is the reference point
- turn crankshaft until the TDC marking on the flywheel aligns with the point on the adjusting tool (arrow B) and the markings on the injection pump sprocket and mounting plate
Checking and adjusting
- removing sealing plug on injection pump head
Note
Always replace cover plug gasket and tighten plug to 15 N-m (11 ft.lb.). If leakage occurs plug can be retightened to 25 N-m (18 ft.lb.).
- install adaptor and dial indicator (0 to 3 mm) in place of plug and preload gauge to approx. 2.5 mm.
- turn engine slowly counterclockwise (opposite to normal rotation) until dial gauge needle stops moving
- zero gauge
- turn engine clockwise until TDC mark on flywheel is aligned with boss on bell housing
New Specifications
Read delivery on gauge:
^ Normally aspirated diesel:
Check value: 0.83 - 0.97 mm stroke
Adjusting value: 0.90 +/- 0.02 mm stroke
^ Turbo diesel:
Check value: 0.95 - 1.05 mm stroke
Adjusting value: 1.00 +/- 0.02 mm stroke
Note
If figure is within specified tolerance (checking value) it is not necessary to reset injection timing. -if readjustment is necessary, loosen two upper mounting bolts and rear support bolt
- loosen lower mounting plate bolt from front through hole in pump sprocket (arrow)
- adjust delivery of the injection pump by turning pump until reaching adjustment value
- tighten mounting bolts to 25 N-m (18 ft.lb.)