High Speed Cut-Out

Cody Forbes cody at 500tq.com
Wed Aug 18 21:49:27 EDT 2004

High speeds is a relative term. First off do you mean vehicle speed or
engine speed? Second by high speeds do you mean 70mph or 170mph...well not
170mph for sure but you get the point ;-).

Have you watched your boost level while this is happening? If you see 1.5 on
the digital gauge then you have most likely a bad wastegate diaphram and
your overboosting which hits the cutout. Lifting off the throttle then
getting back on would buy you some time to accelorate while the turbo
spooled back up, but then it would hit the cutout again eventually.

As far as speed limit cut-outs these old cars don't have anything other then
a lack of power to go too fast.

-Cody Forbes
'86 5ktq EFI
'87 5ktq EFI/K27/272cam/headwork - Has pinned the 160mph speedo once
'88 80 4cyl
'88 90 4cyl

----- Original Message ----- 
From: "Mark J. Besso" <quattro at audisport.com>
To: "Audifans" <quattro at audifans.com>
Sent: Wednesday, August 18, 2004 2:49 AM
Subject: High Speed Cut-Out

Vehicle in question: 1986 5000 Turbo Quattro Wagon

Is it normal for this type of vehicle to cut out at high speeds?  I found
that if I backed out of the throttle slightly it picked back up.  It would
cut out again, but at a slightly higher speed.

I finally gave up when the "Antilock Off" light came on. (Not related, but
equally annoying)

Is this caused by something electronically cutting boost and/or ignition?

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