Re: Help, Dropping Boost

[raf40@oes.amdahl.com (Richard Funnell)]

Paul,

A previous car of mine, a 5KT, started having similar boost problems and it
turned out to be the turbo bearings getting fouled.  The theory was that I
wasn't running the car before shutting it off after a highway run.

Earlier, that same car had problems developing boost and it was a clogged cat.

I used a can of carb cleaner to look for leaks some time ago on my urQ.  I
found them at the injector seals and the accordion hose.  All I did was
spray it at suspicious things and if the rpm increased, I had found a leak.

>I have a little problem I have been trying to fix
>without success.  Over the last four months of
>driving my Ur-Q, the maximum boost attainable has
>been dropping. In december I reported times of
>11.2 stock boost and 10.2 with 15 psig.  This last
>week in the stock configuration I was getting near
>14.0, and I can't achieve 15 psig.  In addition,
>I have noticed some reduction in the speed of
>boost increase.
>
>I have thouroughly done over the schrappnel knobben
>and removed it as a possible source of problem.
>Since stock boost times are effected this isn't
>suprising.  I have had some problem with the
>accordian hose, but have added another layer of
>material to close off any possible leakage.  I still
>hear some hissing under boost.
>
>Could this been air coming out the cruise control vavles
>at the pedals due to a bad one way valve?
>
>Would that effect boost by reducing the wg control pressure?
>
>Is there some other area I should concentrate on?
>
>I have used a propane torch as a leak detector with
>no positive indications.  Any hints on it's proper
>application?
>
>Thanks in advance to the net at large for any assistance.
>
>paul timmerman
>
>(gruby of nail, weak of back, but determined to break 10.0 by sunday)

Richard Funnell,
San Jose, California
'83 urQ
'87 560 SL