[s-cars] RE: New MAF tested to fix stumble / low boost issues

[Walsh, Edward]

Billdge,

I keep forgetting to do that!  I know there is a recommended procedure for
performing this task (Schrader valve/block crankcase breather, etc), but I
can't recall what precisely to do.

Can anyone give me some advice?

Thanks, Ed


-----Original Message-----
From: wmahoney at disk.com [mailto:wmahoney at disk.com]
Sent: Thursday, April 24, 2003 3:17 PM
To: Walsh, Edward
Cc: s-car-list at audifans.com
Subject: RE: New MAF tested to fix stumble / low boost issues


EDdy,
Have you actually pressurized the intake manifold to check for leaks?  I
sort of recall a long ago post from Igor possibly, that reported a very hard
to find leak in the michelin man Xover hose.  IIRC it was right in a seem
that was rather difficult to detect.
And as there seem to have been such a number of mtm1 problem postings of
late, perhaps that software sucks as opposed to blows?
Bill m
95 1/2 Avant -ALL rs2 stuff smooth and steady to 27psi

-----Original Message-----
From: Walsh, Edward [mailto:edward.walsh at agedwards.com]
Sent: Thursday, April 24, 2003 1:37 PM
To: 'wmahoney at disk.com'
Cc: 's-car-list at audifans.com'
Subject: New MAF tested to fix stumble / low boost issues


Bill/List,

I installed a loaner MAF (thanks for the loan BILL M!) last night.  On the
way into work this AM, the car was seemed smoother, etc.  Alas, the boost
did the same thing (shoots to 16, then slowly creeps to 20 - fluctuates
along the way - every other MTM 1+ car that have driven would shoot to 22
PSI, and back off from there).

The good news is the engine didn't stumble at all.  I don't feel I have
enough miles on the car with Bill's MAF, so I can't say for certain that my
MAF was/is bad.  In the past, with the my MAF installed, the car would
stumble sometimes/sometimes not, though it was hard to predict when.   So, I
am guessing my MAF is weak/bad, and Bill's is good... But I still am having
a problem somewhere else with my boost.

(maybe this will be useful for the archives)  Back to the list:

95 S6 with 83k - MTM 1+ ECU
- Plug connectors all have 5K ohm resistance (swapped in known good
connectors - same problems)
- ECU is good (swapped in known good ECU - same problems)
- Hoses are tight/secure
 - Plugs are good (swapped in known good plugs - same problems
- WGFV is good (clicks during diagnostic test)
- Coil pack is good (swapped in known good Coil Pack) - same problems
- Idle is smooth
- New O2 Sensor
- Turbo is quiet
- Waste Gate is not torn, slides smoothly up and down with no radial play
- Power is smooth until about 1.2 bar
- Miss is subtle, but prevents boost from hitting 22-23 (MTM 1+) in all
gears.  Boost is lower as the gears are higher (2nd gear will hit 20 PSI
right away 5th gear goes to 17 then creeps to 20/21 over the span of 5 or so
seconds), Miss is worst when accelerating hard at hway speeds, after
coasting in heavy vacuum for a while (like slowing for traffic on a 2 lane
road, downshifting from 5th to 4th, then overtaking on the left) - Motor
will over boost to 28+ PSI if floored at low RPM (<2,500) in 3/4/5 gear.
When boost is that high, the motor makes a different, very rapid "thumping"
noise. ECU will sometimes bring boost down to safe levels, but sometimes it
won't, and only my right foot prevents a grenade.

Any more Ideas? Anyone have the pn for a WGFV

Thanks a million, Ed


--------------------------------------------------------------------------
Notice: Since e-mail messages sent between you and A.G. Edwards &
Sons, Inc. ("AGE") and its employees are transmitted over the
Internet, AGE cannot assure that such messages are secure. You
should be careful in transmitting information to AGE that you
consider confidential. If you are uncomfortable with such risks,
you may decide not to use e-mail to communicate with AGE. Although
you may be sending an e-mail message to a specific AGE employee,
other AGE employees may review such messages. Additionally, your
e-mail messages to AGE may, consistent with AGE's regulatory
requirements and retention policies, be retained. You should also
be aware that e-mail messages may be delayed or undelivered. AGE
does not accept orders to effect transactions or other similar
instructions through e-mail messages.
---------------------------------------------------------------------------