RE: '87CSTQW Engine under load cuts out momentarily.

["Ned Ritchie" <NED@IntendedAcceleration.com>]

Also, maybe, a split in the wastegate diaphram.  In effect the diaphragm
doesn't  work.

 -----Original Message-----
From: 	owner-quattro@audifans.com [mailto:owner-quattro@audifans.com]  On
Behalf Of DeWitt Harrison
Sent:	Thursday, June 10, 1999 1:22 PM
To:	BSWANN@arinc.com
Cc:	quattro@audifans.com
Subject:	Re: '87CSTQW Engine under load cuts out momentarily.

On Thu, 10 Jun 1999 11:34 -0400, Ben Swann wrote:
>[  ... ]
>Onto the next question.  When I'm accelerating and hit 1.5 on the
>barometer, the car bucks as if the ignition or fuel pump is shutting
>out momentarily.  This is rather aggravating and seems almost
>dangerous especially when passing.  The engine kicks back in when
>boost drops to 1.4 and is insistant to not accelerate so hard - to me
>it seems that the car is just getting into its power band.

Congrats on acquiring Daddyhood status.

Your ECU should shut off the fuel pump at 1.5 bar as an engine
protection measure, so that much is working correctly. I would
say your waste gate is stuck closed and failing to relieve exhaust
manifold pressure at the correct pressure of 1.3 to 1.4 bar absolute.

"Chipped" ECUs typically have had the cutout pressure threshold
value increased or, in some clumsy code hack jobs, eliminated.
Speaking of clumsy hack jobs, it is also possible that a former
owner intentionally altered the WG to prevent it from
opening. You should figure out why the WG is not operating
correctly and repair it. If that little taste of "over boost" has
wetted your appetite for running boost pressures above stock,
look into installing a properly engineered ECU/WG upgrade kit.

DeWitt Harrison
Boulder, CO
88 5kcstq