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Re: Hiccups under boost...

At 06:56 AM 5/12/96 -0500, you wrote:
>For the last month or so, I've been chasing an intermittent problem with my
>'89 200q.  On occasion, the car won't run cleanly at greater-than-OEM boost
>levels: It pulls fine up to 1.3 or 1.4 bar (per the OEM gauge) then hiccups
>and bucks as if it was missing or had a tank of bad gas.  Other times, even
>just a few minutes later, it pulls fine all the way to 1.8 or 1.9 bar...
>The ECU is totally stock, the increased boost being achieved with a stiffer
>spring in the wastegate, and the knock-sensor indicator on the dash doesn't
>light up, which suggests it's not a timing problem.  It happened again this
>afternoon for a few minutes but didn't happen after the car had been parked
>for a while.  I thought it might be heat-related -- it hit 107 here per the
>climate control thermometer -- but it was 105 when it was working okay so I
>think that's not it.  I've checked the diagnostics for fault codes but came
>up empty-handed.  BTW, my car is an 89.5 with dual knock-sensors and I have
>recently replaced the cap/rotor/plugs/wires with OEM Bosch parts as well as
>installed a K&N air filter, for what that's worth.  Otherwise, it's a stock
>car w/100k on it...
>Does anyone have any clues or suggestions for me?  It runs just fine as the
>factory intended but I don't want to go back -- No, make that CAN'T go back
>(you know what's said about power and corruption!) -- and since I'm waiting
>until the problem has been solved before installing the RS2 turbo and other
>go-fast goodies I bought over the past few months, it should be clear why I
>am anxious to find a cure for this and quickly...
>     _             _             
>    / l       l o l  \       l o   Jeffrey Goggin
>   /__l l l / l l l  l l l / l l   * * * * * * *
>  /   l l_l \_l l l__/ l_l \_l l   AudiDudi@delphi.com
  It sounds like a problem I had been having with one of my cars with the
charlie spring.  Turned out to be a small tear in the I/C to manifold hose.
I didn't think to check that until the problem got to be so bad that it
would not boost above 1.5bar, but when I changed the hose, it ran fine all
the way to max boost.

               Michael Loeks
               '86 5kcstq - Red w/ Fuchs/D60A2 wheels 1.8 bar boost
               '86 5kcstq - Grey w/ stock wheels/Comp T/A HR4 1.8 bar boost
               '84 Ford F350 dually flatbed(NOW we're talking utility)
               Warren, Oregon