[s-cars] Fw: Hoppen Stage IV - boost (or lack thereof) issue

[Keith Maddock]

Perhaps I missed something, I read Marc's post as saying his boost gauge is always at zero no matter what.  To me, this means it HAS to be a leak somewhere in the boost control system.  If the turbo failed, I'd still think he'd see vacuum readings on his boost gauge, right?  Marc can you confirm or reclarify your boost gauge behavior?

If you are certain there is no problem with the boost control hoses, perhaps there is some sort of failure in the WGFV system.  If you unplug the WGFV you are stuck with  max 5psi of boost (or more if you have played with your WG spring).  This, however, is very smooth in operation.  Check the electrical and hose connections to the WGFV, some of my hoses looked a little suspect when I looked at mine.  On my car, I experienced intermittent electrical connections on the WGFV, but that led to overboosting to 30 psi, which is the opposite of your problem.

Maybe another lister can help by loaning a ECU and WGFV for "swap-diagnosis"...

HTH,
Keith
93 S4  (4000 miles away)

****************************************************************
Keith Maddock, TRW Automotive,  Koblenz, Germany
Slip Control Systems, Systems Design, Traction Control
+49 (0)261/ 895 2474     -    -    keith.maddock at trw.com

>>> "Fred Munro" <munrof at sympatico.ca> 22:23:54 15.09.2002 >>>
Hi Marc;

I hate to belabour the obvious, but have you checked the pressure hose to
the ECU at the fuel seperator? This commonly pops off under pressure and the
ECU shuts down the boost. Depending on where you tied in your boost guage,
it may also cause your gauge to read zero.
Just a quick check you can do before you tear your turbo apart.

HTH

Fred Munro
'94 S4

-----Original Message-----
From: s-car-list-admin at audifans.com
[mailto:s-car-list-admin at audifans.com]On Behalf Of Marc Weiner
Sent: September 15, 2002 8:49 AM
To: s-car-list at audifans.com
Subject: [s-cars] Fw: Hoppen Stage IV - boost (or lack thereof) issue


This is a multi-part message in MIME format.
--
[ Picked text/plain from multipart/alternative ]

Hey all, don't post often.  I have a 94 S4 w/ Hoppen Stage IV (est.360hp)
RS2 turbo, exhaust man., injectors, lehman re-worked cyl. head, lower
compression pistons, lehman stage IV chips (same car written up in EC w/
Frank "Don" Amoroso, Mark Hunter, etc.)  Anyway, I was doing a typical
commute to Denver from Ft. Collins and somewhere in the middle of it I lost
all boost.  Car seems to be running on just the 20V 5cyl. w/ no turbo
assistance (or maybe very little).  I have gone through all the hoses (not
getting any wooshing sound -like its blowing out somewhere BTDT many times
(have all 3 of the samco sport hoses and and the upgraded adjustable (metal)
WBV from Dave Jones.  I know what it sounds like when a hose has popped off
and that is that the case here.   I am getting absolute 0 reading on my TDO
0-30psi boost guage (needle won't budge even on full throttle) - car had
been consistently making 25-26psi at full throttle overboost.  There are no
warning lights coming on.  Car had been running flawlessly, however, I do
have 180k on the clock.   Any ideas????- could it be an ECU or pressure
sensor problem (the ECU has a 3.0 bar pressure sensor/transducer).  Thanks
in advance for any help. . . .I am stumped.
Marc Weiner
Ft. Collins, CO

--

_______________________________________________
S-CAR-List mailing list
S-CAR-List at audifans.com
http://www.audifans.com/mailman/listinfo/s-car-list

_______________________________________________
S-CAR-List mailing list
S-CAR-List at audifans.com
http://www.audifans.com/mailman/listinfo/s-car-list