V6 with engine fire?

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

In message <m0xi12k-000FhuC@post.cis.smu.edu> randrews@post.cis.smu.edu (Robert Paul Andrews) writes:

> I was at a junk yard the other day in Austin and they had a 93 90, with a
> engine that caught fire.  What would make it catch fire like that?  The 
> whole thing was burned up pretty bad.  Just makes me wonder, mechanic fault or
> owner fault or Audi's fault......

a) Bad workmanship on the fuel injection system.  Re-using the sealing washers, 
   for instance, or not tightening to the proper torque.
 
b) Mechanical failure.  On the later CIS systems, there is an external pressure
   regulator that contains a diaphragm supposed to be open to air.  It seems to
   be acknowledged that there is a finite danger of this diaphragm rupturing
   and delivering fuel at ca. 6.1 atmospheres in a fine spray across the 
   engine.  This is the valve that has a square block on one end (draining
   back to the tank), two fuel lines bolted to the cylindrical body, and a
   small hose connection on the axis at the other end.  This small hose 
   connection should drain to somewhere safe, such as the air boot over the 
   mass sensor.  Every hose I've checked so far would not have been up to the
   task of containing a fuel leak.

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

 (Coming to you from the country that thinks T-bone steaks are as dangerous
  as handguns.)