Fuel Dist. Rebuild

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <203570@isham-research.demon.co.uk> quk@isham-research.demon.co.uk (Phil Payne) writes:

> In message <3443C398.3D29@ast.lmco.com> russ southerlin writes:
> 
> > I think I saw in the archives where back in Aug. you were trying to come
> > up with parts and procedure for rebuilding fuel distribotors. Well I did
> > the dumb thing of taking mine apart (thought it was contaminated) and
> > now it is leaking. Any help would be appreciated.
> 
> This has so far been a long learning curve, and we're not done yet.

A few other points I forgot:
 
a) In general, you have to follow the guidelines on replacing a head as 
   documented in the fiche (and perhaps Bentley?).  This means, among other
   things, very carefully measuring the plunger's protrusion from the 
   bottom of the head _before_ taking it apart.  You need to work to around 
   0.05mm.  If you didn't do this - you're in deep weeds and will have to do a 
   'ground up' air mass sensor recalibration.  This is a tedious business and 
   requires some precision measuring equipment - a digital depth gauge is damn 
   useful, and a CO meter, an rpm meter and a multimeter.  And a _LONG_ 3mm 
   Allen key for adjusting the air mass sensor.  You can adjust the plunger 
   quite neatly with a pair of circlip pliers, though there is an official tool 
   - a Hazet 2655-2.  The world's most expensive screwdriver?

b) The mounting O-ring (between the head and the air mass sensor) is more 
   delicate than it looks. We find that they last for three head swaps at most 
   before becoming hopelessly distorted.  It's easily our biggest consumable.

c) Methylated spirit is best for cleaning the head surfaces.
 
d) One of the failure modes just pumps fuel straight through the injectors.
   This results in hydrolock in any cylinders that have their inlet valves
   open, and lets lots of fuel mix with the engine oil.  BTDT.  Watch for
   a kind of high-pitched whine when the fuel pump kicks in, and turn it 
   off QUICK!

I've made a major investment in a set of Stahlwille crowfoot flare nut sockets 
- the damn things are around $40 _EACH_.  You really need 12mm and 14mm for the 
head, and 17mm for the fuel pressure control valve.  I also have 6mm and 10mm 
Allen keys with most of the short leg ground off for use in the cramped engine 
bay of the ur-quattro.  I can do a complete head swap in around 20 minutes now.

-- 
 Phil Payne
 Committee Member, UK Audi [ur-]quattro Owners Club