5kCSTQ boost Q (fwd)

[quk@sievers.com (Phil Payne)]

In message <199608261852.LAA28924@netcom2.netcom.com> Orin Eman writes:

> 5th gear, WOT, 2500rpm plus.  The boost built up and kept building up to
> 10psi at which point I did hit the fool pump cutoff.
> 
> Everything is fine on the 3rd gear 35 to 55mph test.  Anyone know if lower
> rpm behavior is different?

It shouldn't be.

a) Has the car been "chipped"?
 
b) How warm was the engine - i.e., how _recently_ had it warmed up?
   Had it just reached a reasonable operating temperature, or had you been 
   driving for a while?  I ask because several MB owners (in fact, all 
   who've tried it) have been able to demonstrate an overboost window
   just as the engine reaches operating temperature.  Myself, John
   Robinson and Steve Evans have all been able to reproduce this problem.
   We suspect an ECU map bug.  In fact, if anyone feels like mistreating
   their car just once by hitting the loud pedal _HARD_ just before the
   "N" symbol is reached on the water temperature gauge, we might see if
   this is common to more than one design.  It happens in all gears.
 
c) Are the small-diameter wastegate control hoses, to and from the 
   overboost control valve, frayed internally at the ends?  Sometimes the
   rubber perishes through inside the fabric - if you cut the last 1/2"
   off the hose, you'll find a fretwork inside.  Sometimes they chafe
   through on things like cable ties.

--
 Phil Payne
 phil@sievers.com
 Committee Member, UK Audi [ur-]quattro Owners Club