RE: Power Loss During Warmup

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

... if this is suspected ... and if the MC engine is anything like my WX
engine I would suggest one possible culprit ... the electrical connector to
the "OXS Frequency Valve" on the loom a few inches away from the valve.  On
the ur-q it is pretty busy right there ... and it may be so on the 5k as
well as I can't recall ever actually seeing the OXS Freq Valve on my Avant
... that electrical connector is not protected from the elements by anything
in particular so it is easy for corrosion to occur on the pins ... it has
happened to my car a couple times, but fortunately it would do this while
idling.  It was quite obvious that there was a correlation between the
buzzing stopping and the car starting to idle like crap ... buzzing comes
back on and the idle straightens up.  Perhaps I'll hack an OXS heater
connector set from a car in a wrecking yard some day and install a proper
connector there ...

Another source of a similar problem on the WX engine is the infamous intake
manifold ground.  The MC isn't known for this symptom AFAIK, but it could be
that the ground braid from the engine to the frame of the car is in need of
repair ...

HTH!
Steve Buchholz
San Jose, CA (USA)

	----------
	From:  Avi Meron [SMTP:avi@cosmoslink.net]
	Sent:  Monday, April 05, 1999 8:58 AM
	To:  Doyt W. Echelberger
	Cc:  Quattro
	Subject:  RE: Power Loss During Warmup

	Doyt,
	Sounds as your frequency valve is coming on and
off...............(will
	cause exact symptoms that you are describing),
	Avi

	-----Original Message-----
	From:	owner-quattro@coimbra.ans.net
[mailto:owner-quattro@coimbra.ans.net]
	On Behalf Of Doyt W. Echelberger
	Sent:	Sunday, April 04, 1999 11:01 PM
	To:	Quattro List
	Subject:	Power Loss During Warmup

	My 87 5kcstq at 150k miles starts on first crank, runs fine for 1-2
	minutes, and then begins losing power and running so badly that I
can't
	keep up with traffic. This condition continues for about 18 minutes,
and
	then gradually gets better and finally the car runs just slightly
off its
	best form.

	After about 20 miles on the turnpike, the car runs normally and gets
better
	and better the longer I drive it. Tonight, after 2 hours at a steady
65
	mph, engine management was very stable and power was satisfactory.
The
	engine did not cycle up and down at stoplights and toll booths, and
did not
	stall out and refuse to start for a few minutes, as it did during
the
	initial 20 minute warmup phase.

	WHAT HELPS? During the loss of power-RPMs falling off-going to stall
out
	pretty soon-phase, I can drop down into 2d gear and tramp the
accelerator.
	The engine grabs, the neck snaps, and the car races off like it had
wings.
	In traffic this lasts about a second and I have to let off and coast
out of
	gear, with the engine reving about 3k. Then I can put it back in
gear and
	drive a few more seconds and do the floor-it again. Sort of like the
Easter
	Bunny hopping down the highway. WOT works great during the warmup
phase.

	WHAT ELSE HAVE I DONE? Ran through a half tank of new high test gas
laced
	with gas dryer and Techron. Tried to blow out the carbon by running
in 2d
	and 3d gear at about 5k-6k for a few minutes. Engine runs great at
high
	RPMs and light load. Refilled tank with Sunoco Ultra 94 octane and
another
	bottle of Techron, ran 4 hours on turnpike at legal speeds. Came
home,
	parked it, and sat down to write this up.

	WHAT'S NEXT? Car goes into mechanic at 8 AM Monday, with this
report, as
	you see it. I want him to have it sitting in front of his shop,
engine
	cold, at 8 AM.    (So he can experience the power loss during the
warmup
	phase.)

	DATA POINTS: Ran fuel pump fuse test and got 4444 readout. Dash
showed 'OK'
	at startup. Used voltage tester (cheap neon bulb thing) and found
current
	at all sensors but no current at either terminal of the ISV while
the
	engine was running. Pulled fuel pump relay and popped off cover,
insides
	looked fresh and new. One plug blade of the fuel pump relay appeared
	bluish, like it had been heated and cooled down. Two weeks ago the
fuel
	pump could be heard briefly from an open driver's window. Then it
quieted
	down.

	That's about all I can tell you.

	I am hoping something in the story will ring a bell in the memory of
a
	fellow lister, and you will tell me enough before 8 AM tomorrow that
I will
	not have to pay my mechanic several days wages while he takes the
entire
	system apart and swaps every sensor and relay and module and ECU
while
	blindly searching for the cause of the condition. He drives a 5kcst
	automatic, and is very familiar with the car, but BTDT would be very
much
	appreciated.

	Doyt Echelberger
	87 5kcstq