Basic tuning of the AAZ - few questions...now with pics

[mugly]

Hi all, new to the forum and i've got a 95 vento AAZ.
Looking to tune it up for a bit more power and i've already searched but to no avail.
The FAQ '1.9td faster' thread is missing a few basic pics about hooking wires together before i can adjust fuel and boost.
Could someone run through exactly what i need to do with the wires and solenoids and do you have pics? Do you need to reset these wires before you up the fuel and boost as i still want the car economical on the frequent long journeys i do.

http://vwdiesel.net/phpBB/viewtopic.php?t=579

Is it possible to get better MPG by turning the max fuel screw out and doing nothing else as the MPG seems quite low at the moment? (max fuel screw hasn't been tampered with yet)

I know they're 2 different questions but i'm a bit of a noob when it comes to diesels :lol:

Pics as promised if people can help

[Vincent Waldon]

Hi there, welcome, and congrats on reading the FAQ first... a perfect start to learning about these engines!

In terms of your first question, there's a bit of controversy regarding the additional solenoid on the typical AAZ pump.  According to the Bosch service documentation its purpose is to slightly retard timing when triggered by the engine control module (evidently under low power conditions etc).

Some instructions I've read say just connect it to 12V, others say leave it disconnected.  My opinion: its effect is so subtle either way, particularly if you've advanced the timing slightly anyways (as most people end up doing) and I personally opt to leaving it disconnected.. less wires, things to go wrong, etc.  On my own pump I ran it both ways for a couple of weeks and noticed no difference, other than a slight increase in pump noise with the solenoid connected.

Having said that, I remember a post from one of the members of this gang who said that there's a particular version of the pump where the solenoid must be connected or pump damage could result... might be worth a bit of a search.  As I recall the pictures of said pump looked completely different from the standard AAZ pump.

I also get rid of wires to the microswitch on the top of the pump... I delete the switch and the wires.  Among other things they are used on some "Eco" versions of the engine to trigger the turbo... my turbo is full time thank you very much. :wink:

In terms of mileage:  for starters, if you're somewhere in the world with any kind of winter you can expect your fuel economy to decline 10-25% in the winter automatically, mostly due to increased friction and the vendors switching to a winter blend of diesel that has significantly lower BTU value.

You can tweak the max fuel screw a bit but my experience has been that any fuel economy gained comes at a fairly drastic reduction in power,  so you need to put your foot in it more, and you use the same fuel... if not more.

Just some thoughts... no doubt others will chime in with their AAZ thoughts.  Some day we should clean that FAQ post up a bit, huh ?!!

[mugly]

Right ok i think that makes sense.
At the moment i've tweaked the screw inwards and i'll be adjusting the idle screw to suit so in effect getting more power when i put my toe in but not really affecting the overall MPG if i drive sensibly? If that makes sense.

Pic of my engine if you can tell what turbo etc i'm running...will try and get a close up of the pump and asscociated wires.

[Vincent Waldon]

Ok, that picture helps.

Your AAZ has the full EGR setup, which if memory serves means your turbo might well be governed by the throttle switch.  One way to check is to find the turbo's wastegate and see if there's a small line directly from the intake side of the turbo to the wastegate, or longer lines that lead to a solenoid valve usually bolted to the passenger side shock tower.

If so, a potential performance upgrade is to delete the extra hoses, solenoid etc, and simply connect the wastegate to the intake directly... full time turbo.

[mugly]

Ok, that picture helps.

Your AAZ has the full EGR setup, which if memory serves means your turbo might well be governed by the throttle switch.  One way to check is to find the turbo's wastegate and see if there's a small line directly from the intake side of the turbo to the wastegate, or longer lines that lead to a solenoid valve usually bolted to the passenger side shock tower.

If so, a potential performance upgrade is to delete the extra hoses, solenoid etc, and simply connect the wastegate to the intake directly... full time turbo.

Ok cool, will have a check...any info on how to convert to full time turbo as the pics are missing from the 1.9td faster thread

[LoneWolf]

UK Mugly? where abouts?

[Vincent Waldon]

any info on how to convert to full time turbo as the pics are missing from the 1.9td faster thread

This just means deleting the extra tubing, solenoid valve etc between the wastegate and the intake scroll and running a short piece of hose directly between the two fittings.  When you look at the wastegate it will probably all make sense... if not, post a picture or two and we can point you in the right direction.

[mugly]

UK Mugly? where abouts?

Yeah sorry guys UK based, Midlands...lichfield to be exact

Thanks for the info dudes, will get pics up on sunday if i've got a spare 5 mins

[nogama3]

hi there fella, i'm too from the midlands - nuneaton so not too far away.
i am a complete idiot when it comes to anything technical involving engines and i used dervdoctor in derby to get my work done. cost approx 2 hours work.
give gavin a call if you get stuck.

[mugly]

updated with piccies, can anyon run me through the basics?
Already turned up the max fuel screw a couple of qrtr turns and adjusted the idle.
Am i needing a 1.6td boost pin or a rover 220td one or can i use the original 1.9?

[veedubcanuck]

On my AAZ when I put constant 12v to the timing advance solenoid (front of the pump) it made a big difference at low end RPM. It makes NO difference to the middle to upper end. In my case I could really feel it when the switch was energized when you take off from lights as it felt kinda sluggish and then there was a jump in power after you got to a certain RPM.  You might want to block off the EGR too. It can cause more headaches than good, ie. plug up your intake system with carbon, plus it reduces power and economy. Just make sure you can hook it up easy enough if you have to pass emissions.

[mugly]

On my AAZ when I put constant 12v to the timing advance solenoid (front of the pump) it made a big difference at low end RPM. It makes NO difference to the middle to upper end. In my case I could really feel it when the switch was energized when you take off from lights as it felt kinda sluggish and then there was a jump in power after you got to a certain RPM.  You might want to block off the EGR too. It can cause more headaches than good, ie. plug up your intake system with carbon, plus it reduces power and economy. Just make sure you can hook it up easy enough if you have to pass emissions.

How do i go about blocking up the EGR and which bit is that  :lol: sorry for the dumb questions as i don't want to fook it up

[nogama3]

i took my egr valva off, took it to an engineering placing and asked them to make blanks to fit both ends, cost around a tenner i think.

[Vincent Waldon]

The good news, based on the pictures, is that you have the simpler emissions setup... no microswitch on the IP to worry about, and as far as I can tell your turbo is already full time.

The bad news is that you have what's known in the biz as the "joke" boost pin... so named 'cause it's usefulness is laughable.  You won't just be able to jam in a 1.6 boost pin (at least not very effectively)... to modify the boost fueling properly you'll most likely need to find a different pump top in which the LDA (the spaceship-looking thing that houses the boost pin) has the proper adjustments and spring.

The EGR stuff is your third picture... thin tube that routes exhaust gases back into the intake manifold to reduce emissions.

[mugly]

The good news, based on the pictures, is that you have the simpler emissions setup... no microswitch on the IP to worry about, and as far as I can tell your turbo is already full time.

The bad news is that you have what's known in the biz as the "joke" boost pin... so named 'cause it's usefulness is laughable.  You won't just be able to jam in a 1.6 boost pin (at least not very effectively)... to modify the boost fueling properly you'll most likely need to find a different pump top in which the LDA (the spaceship-looking thing that houses the boost pin) has the proper adjustments and spring.

The EGR stuff is your third picture... thin tube that routes exhaust gases back into the intake manifold to reduce emissions.

Ah right ok, so pointless getting a different boost pin for this pump then?

Did a search on the EGR blanking and had a quick go at knocking a blank up earlier, fitted it and tweaked the fuel a bit more and tbh i can tell the difference...certainly made it a bit quicker and it doesn't seem to lag higher up the rev range