AAZ with electrically controlled timing advance

[Ghia]

I finally managed to find an AAZ engine for my T3 van from a 1995 Passat.

It doesn't have an immobiliser but the diesel pump does have 2 sets of wires coming out which I currently don't have connected up to anything.

Having read through previous posts, the general idea is that these are for advancing the timing at certain points within the rev range via a small ECU or box of relays...

Does anyone have a definate idea of what exactly this all does and what effect it has on how the engine runs?

I'm driving around without them connected and it seems to go well enough although it's fairly noisey and doesn't like to start much.

Here's a pic of where the wires come from on the diesel pump.



MG

[bigblockchev]

If I understand teh VE pump internals correctly teh section which can cause an advance in the timing is directly forward of the lower yellow circle in your pic. It has two torx screws securing it on a diamond shaped plate. The back side of the pump is where the cold start advance is hooked up to. In your pic the plug between the injector pipes is the one where you mount the dial guage to do timing, so it could be some sort of measurement sensor or switch but I can't see it changing the timing as it is in the wrong place for that to happen.  Cheers Dan

[Tintin]

http://vwdiesel.net/phpBB/viewtopic.php?t=9273

[bigblockchev]

I stand corrected thanks Tintin

[Ghia]

Does anyone have access to a wiring diagram for this engine?

Am I right in thinking that if the timing fails safe to full advance, that the performance shouldn't suffer at all but thta the engine will be a bit more noisey than normal?

Thanks again.

MG

[burn_your_money]

I have the engine wiring harness if that is of any assitance

[Baxter]

Autodata has the wiring diagram Mike.

[Ghia]

Tyler,
Do you have just the engine loom or the loom including what went into the car etc?

Any pics?

Thanks
MG

[burn_your_money]

Only the engine loom up to the big connector on the side of the engine by the metal coolant pipe

[Ghia]

Ok I already have that part and have removed it  :lol:

I'm looking for the next bit and most importantly the small ECU whatever it is.

Thanks anyway

MG

[Ghia]

After a small trip to the breakers I now have the double relay box (ECU) which matches the diesel pump.
It has 18pins and takes into account all sorts including engine temp, glow plug control, pump timing, keeping the glow plugs on after the engine us runninc etc.
I've connected up the bare minimum to it to get the system running with the timing advance/retard setup. The wiring is very simple to follow, just a feed, earth, switchable feed and then 4 wires from the pump.
There is a noticable difference at tickover of less noise so it's obviously retarding the timing there.
I'm going to be driving over 400 miles this weekend in it so we'll see how it does.
MG

[Ghia]

Well just connecting up the bare minimum to get the unit working results in a loss of power!

I drove for 80 miles wondering if it would change at any point. It didn't.

It could be that I need to connect up temperature senders to the unit etc as more advance may be allowed once the engine is hot enough but as I had to remove those for the normal temp sensors for the van that's not an option right now.

So I'll run it without and it seems to be fairly happy with good power delivery.

MG

[jc_geddes]

Mike

from what I have managed to find out the ecu will be looking for a engine speed signal - it uses this to alter the timing.  The signal I think comes from the W conector on the alternator.

With out this I think the ecu will think the engine is not running and set the timing to the cranking position and not alter it (advance it) as the engine speed increases, hence your power loss.

I am only guessing about the above but it makes sense.

Would it be possible to send me some pictures of the ecu?  I have been looking for one for my aaz conversion but the vw breakers around coventry just look at me funny when I ask them!

Also where was it on the donor vehcile? I think they are located above the fuse box but I am not sure.

Eqwually if you can't be bothered to have a play with it do you want to sell it me?

Cheers

John

[Giles@PerformanceDiesel]

hi  guys

can u give me the pump part # and i will look it up on the Bosch system
and i would like to find out the internals of this pump.

the Bosch part # should read like this

0 460 *** ***
if u can't read that then the VW #

Giles

[Ghia]

Giles,
Sorry to leave you hanging like that  :oops:

Having now looked at the pump, the Bosch number is 0 460 194 368. The VW number is 028 130 110 C

Hope this helps and I'd love to know what's going on also  

Thanks for your interest.

Mike Ghia