VW T4 Forum - VW T5 Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
226 Posts
Discussion Starter #1
Hi all..was wondering!! what sort of a difference does it make fitting the AAZ fuel pump??? to a 1.9 td....I have wound my standard pump up and done intercooler mod allready...
And whats involved in the pump swap???
cheers mateys..
 

·
Somebody stop me!
Joined
·
11,941 Posts
Mahooooosive difference if you get the boost pin from Brickwerks as well, do it and you will see what i mean T:T:T:T:T:

In short the boost comes in from no revs and holds all the way to the redline, the idle is stock but you could do with traction controll in the wet to stop it spinning in 3rd gear :eek:
 

·
Registered
Joined
·
226 Posts
Discussion Starter #3
OHH Good!! how much of a job is the swap though??? and the boost pin..is there a picture to identify what you mean..cheers...
 

·
Registered
Joined
·
1,585 Posts
http://www.brickwerks.co.uk/shop?page=shop.product_details&flypage=flypage.tpl&product_id=490&category_id=96&keyword=boost

The 'pin' is ocated vertically from/in the 'spaceship'(LDA) on the top. When 'boost is made it provides positive pressure via the narrow bore line to the LDA/spaceship.

This in turn acts/pushes on a rubber diaphragm. More boost=more pressure=more diaphragm gets pushed down.

still with me?:D

Ok , attched to this diaphragm is one of these pins - various makes/models had varying shaped pins. The importand part is the ramp angle. If you look at the BW link you will see the new one has a very steep/aggresive ramp on it , the AAZ pin is the straight one, an 'eco' pin.

When the diaphragm has boost/positive pressure applied it pushed the attached pin down. If you take the boost pin out you will see in the side of the drilling it sits in there is a very small pin that is at 90' to the boost pin and sticks out into the side of the hole the boost pin moves and down in. So as the boost pin moves up and down this small pin 'rides' on it and vertically.

This pin alters the fuelling internally , the more it moves out the more/extra fuel is provided.

Now , when this small pin rides on the original boost pin it stays in the same position as the original boost pin is the same diameter on its entire length so does not introduce extra fuel so in effect not making much use of the 'boost' the turbo is providing.

With the aftermarket boost pin it has a steep ramp angle. When the new boost pin is pushed down , the fuelling pin riding on it obviously comes out of its position more , introducing more fuel at boost. The more boost you make the more extra fuel (over and above that , that is governed by throttle arm) it introduces.

Thus , the OE boost pin is cack and does not make full use of the boost made by the engine. Turning up the max fuel screw increases fuel across whole rev range regardless of boost. By going for a pump with an LDA you are introducing fuel when you need it.

Simples:*
 

·
Registered
Joined
·
226 Posts
Discussion Starter #5
Hi again...how easy is the actual diesel pump swap???? thanks for the other info.....very helpfull...
 

·
Registered
Joined
·
1,585 Posts
If your competant enough to do a cambelt change than its within your realms of expertie.

3 bolts at front , one at back and remove injector lines-basically it really.

Dti on back of pump to sit pump lift or do it by ear if you havnt (but get it set asap after).

If you do it by 'ear' method , leave bolts snug but so you can still move pump , pull pump towards bumper then slowlyl push it towards head. You will reach a point when you get a rather obvious rattle/diesel knock type sound. Tap it gently back towards radiator until noise just goes.

Never fitted one with a T4 adjustable pully , only done it with non-adjustable pully.
 

·
Registered
Joined
·
226 Posts
Discussion Starter #7
ok..all I need now is a pump...and pennys....thanks for the info....
 
1 - 7 of 7 Posts
Top