electronic advance on AAZ pump - and joke LDA??

[regcheeseman]

Searched and searched and found several threads but seem to not find an answer.

I've got the AAZ pump with the electonic advance doohicky on the underside.

What are the implications of it's removal/disconnection? There are suggestions that it operate in a two stages either on or off - and others suggest that it is controlled by PWM to give more variation.


Also the LDA - I've got the domed LDA top but with the unground pin, I've read that there MAY not be the required internals to give boost enrichment, anyone know if this is the case for sure?

[jtanguay]

that info can be found in the FAQ under how to make your car faster.  it tells what to do with the timing advance solenoid and the LDA pin.

[Baxter]

If it has a boost pin already in then your good to go.
I have run those pumps with the advance doobery firkin snipped off, seems to work okay.
I started researching this recently for a AAZ fitting guide I wrote for the AAZ into T3 booklet I wrote and I stopped counting at 14 different variations!
But, in the UK there are 4 different pump types you are likely to come across.

One good pump, no KSB, no other electrical ***, just a boggo VE pump.
The wanky ECO pump with no LDA provision, castings there, just no internals or drillings.
A okay pump, just has KSB thats all.
Then theres the one you need the small ECU and a VSS to get it to work as it should, this is what you have.

[regcheeseman]

Cheers,

I figured I may as well find the answer out for myself as well.

With the start solenoid wired straight to battery I started the car then unplugged the pump completely - ran fine, If anything pulled better just off idle.

The loom plug housed the glow plug circuitry so I lost this and all instruments but I'm quite happy that the pump will run stand alone.

As for the LDA - I pulled the diapragm out and applied full throttle - there was pressure on the lda pin so I'm happy there is the gubbins in there.

Everyones a winner!

[Hey]

What are the implications of it's removal/disconnection? There are suggestions that it operate in a two stages either on or off - and others suggest that it is controlled by PWM to give more variation.

It is PWM because it wouldn't work otherwise. This pump won't work if you don't have the ECU or if you don't change the advance pistons timing+springs.

A guy on the french part tried and it wasn't working too well. Making an electronic system that would work should not be too difficult but you would need the electronic injector + cranksensor.

[Vincent Waldon]

I think we might be talking about apples and oranges here?

There's a version of the AAZ pump that has an additional fuel solenoid on the underside which is used for altering pump advance slightly for emissions reasons.  Pictures of this version appear in the FAQ under the "make your 1.9 faster" thread, and the general consensus seems to be to play with power or not to the solenoid and see which runs better.  Mine, for instance, runs better without power to that solenoid.

THere's also a "last version before the full TDI" version of the AAZ pump that has completely electronic control of advance... as controlled in a PWM-fashion by the engine control module.  This version of the pump usually also has a "start of injector" piezo sensor installed on the high pressure head where the dial indicator goes.

OP... perhaps have a look at the thread in the FAQ and see which version of the pump you might have ?

[ryanp]

hopefully this will be the case for my dad's pump, We have been under the impression that it will not work, i may as well try it then Reg/baxter?

The car i took the pump off looked to have not had this connected!!

Cheers

Ryan

[anto]

OP... perhaps have a look at the thread in the FAQ and see which version of the pump you might have ?

Mst of the links for photos are dead in that thread unfortunately....

[regcheeseman]

This version of the pump usually also has a "start of injector" piezo sensor installed on the high pressure head where the dial indicator goes.

Yep I've got that.

It is PWM because it wouldn't work otherwise. This pump won't work if you don't have the ECU or if you don't change the advance pistons timing+springs.

Don't be so sure.

I was going to hook the scope up to it but I thought it'd be much quicker just to disconnect the whole lot as a first test.

It runs fine - if anything slightly better at low revs.

I'll hook a scope up to it and publish my findings.

[Hey]

Without any ECU, you have more advance than you are suppose to... if it is the pump with #3 inejctor.


This system serves to decrease timing to the correct amount like in the tdi system.