The VW AAZ Engine
For a long time the VW 1.9TD “AAZ” has been a popular engine upgrade to the T3 however they are getting harder and harder to find at sensible money and so are the injector pipes.
As time has gone on, other more readily available engines have taken over in popularity to retro fit into a T3 but there are still a lot of T3 out there with the venerable AAZ sat in the engine bay doing their thing.
The supply of new AAZ injector lines dried up years ago leaving customer scrabbling around hoovering up what they could from forums and eBay to keep their AAZ ticking along nicely.
After the sad demise of the AAZ in Simon’s own T3 Westy and over 15 years of stirling service pushing the camper up hill and down dale it was replaced with a TDI. This left us with a set of injector pipes that we could have replicated and which we’ve duly done.
This then opened the can of worms of which set of AAZ lines we actually had, you see as time went on the injector lines were updated as were the injection pumps.
The differences
There appears to be 4 distinct injection pump types for the AAZ and 3 different sets of injector line sets. As usual from VW, trying to work with the parts catalogue and work out when and why they changed is a living nightmare with some injector pipes changing on a VIN number and some on an engine number. When you add in the multitude of vehicles that the AAZ is fitted to, well we gave up!
Here’s the different AAZ injector line sets, to the best of our knowledge.
| Cylinder | VW No. | Engine | Date Range | |
| Early Set ’91 – ’94 | 1 | 028 130 301 C | AAZ | ’91 – ’94 |
| 2 | 028 130 302 C | AAZ | ’91 – ’94 | |
| 3 | 028 130 303 D | AAZ | ’91 – ’94 | |
| 4 | 028 130 304 C | AAZ | ’91 – ’94 | |
| Mid Set ’95 – ’98 | 1 | 028 130 301 G | AAZ | ’95 – ’98 |
| 2 | 028 130 302 G | AAZ | ’95 – ’98 | |
| 3 | 028 130 303 H | AAZ | ’95 – ’98 | |
| 4 | 028 130 304 G | AAZ | ’95 – ’98 | |
| Late Set ’98 – ’98 | 1 | 028 130 301 N | AAZ | 98 – ’98 |
| 2 | 028 130 302 N | AAZ | 95 – ’98 | |
| 3 | As “Mid” set | AAZ | – | |
| 4 | As “Mid” set | AAZ | – |
Some engines had an immobiliser over the ELAB (Elektrisches Abstellventil / electrical shut off device), some had KSB (Kaltstartbeschleuniger / Cold Start Device) later pumps had electronically adjustable commencement of injection and some injection pumps had an LDA (Ladedruckabhängiger Anschlag, / Manifold Pressure Compensator) whilst others did not. There are quite a few variables at work here.
Usually the changes to the injector lines are slight, a bend in a slightly different place to give clearance to that new “thing” that they introduced. Our problem is, we have some samples but we are not sure of which age range they are from.
The sample set came from an engine fitted with the nicest injection pump, the easiest one to work with and devoid of all the whistles and bells so our educated guess is that they are from an “Early” set or a “Mid” set, that’s not to say they don’t fit the “Late” engines, truth is we just don’t know!
What we do know that we have a set that works together on a AAZ engine.
As always, we welcome feedback
Links to the lines.
And you may need some clamps.
