Diesel Engines Inj. pumps - AAZ pump adjustments

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HarryMann: Inj. pumps vary a lot, even on nominally the same engines

1.9TD AAZs (usually from Passats) are excellent substitutes for the 1.6 JX TD in many T25s. There are a few gotchas, but here is a picture of a manually adjustable pump, with some notes for increasing fuelling...

File:AAZ Injection Pump.jpg

1) The slotted screw that seems to give it real go and a bit of smoke (but raises the idle) 1/4 to 1 turn in (locknut is 13mm) Main fulelling screw

2) & 3) Don't touch, provides reference face for dial-gauge timing adjustments

4)Solenoid for cold start advance (pulls a cable along engine side of pump which works a lever same side, small travel with adj. stop)

5) Lever boost enrichment (used to have something like this active from cab, when intercooler fitted, for towing caravan, kick-down)

?) Cover for blamked LDA vent.

On the top of the LDA diaphragm unit, selaed under a brass cover, is the boost enrichment spring pretension screw (setting the pressure at which boost enrichment starts?)


Main fuelling screw...

Disel Pump Back 01.jpg