Surging at 11psi

[Bill Elliott <wcelliot@concentric.net>]

Life's never simple with a UrQ!

The problem of the day:  Surging/cutout at 11 psi.

On my 85 UrQ I have the IA Stage 1 kit and a K24.  For the past 25k,
I've been running at 2.0 bar and enjoying every single minute if it.

I have about 10k on the plugs (Bosch tri-electrodes).  Three months ago,
I replaced the IC/IM hose (blew the factory hose).  A few days ago, I
started getting some surging (almost a cut-out) at 11 psi in 2nd gear
when the car was just warmed up (7-10 minutes of driving).  The problem
was not apparent (or very minimal) in 3rd or above or at all after about
15 minutes.

Now it happens constantly.  I have a strong pull to 11psi and then it
flattens out significantly along with some surging/kickback.  Very
occasionally (and always in 3rd or 4th), I get a strong pull to 14psi
and then get the surging.

I checked the WOT switch and found an intermittent short.  I fixed this,
but it made no difference. Tweaking the wastegate allowed more boost,
but the same 11 psi cutout.

This is not rpm-related... strictly boost-related.   It does not feel
like an overboost cutout (but then I've never really experienced one).
Mileage and drivability are otherwise unaffected.

I'm open to suggestions. (No, I'm not selling it!) ;-)

Bill Elliott
Lake Mills, WI
(ps... I finally found a copy of Bill Cosby's "200mph"... the bit based
in fact when Carroll Shelby convinced Bill to trade his Ferrari for a
twin-turbo 427 Cobra.  " I _need_ a car that will do 200mph to the
grocery store"  I had heard it years ago, but had never been able to
find a copy. One of the funniest album sides I've ever heard! "Really
Officer, I was just blowing out the gunk!")