"Bucking" around

Neil Vonhof nhvonhof at attbi.com
Mon Jun 17 18:59:36 EDT 2002

After a 2 hour drive recently in warm (for Seattle) weather suddenly the car
started doing that bucking thing that's been talked about at times on this
list. Couldn't go above 1.1 or 1.2 bar on the dash gauge without complete,
instantaneous failure but then quick recovery and normal performance as long
as I stayed under 1.1. So, today I did a Google search of Audifans using
"bucking" and "lurching" as key words and found enough info. to lead me to
check the MM hose and TBV. A thorough cleaning and inspection of the MM
revealed no cracks, splits or leaks of any kind (it's only a year and a half
old) but a quick glance at the TBV revealed that the vac. line back to the
IM had fallen off. I found that it was frayed and split down one side an
eighth of an inch or so right on the end where it slides onto the nipple of
the TBV, so I snipped off the bad part, removed the TBV so I could really
force the hose back only the TBV nipple, put it all back together and no
more bucking. I guess that was the problem.
I replaced the TBV about a year and a half ago also, and noticed then how
hard it was to get that hose securely on to the nipple and never really felt
sure that it would stay. This time I got it on further than ever before, but
I really had to reef on it hard to get it to move over the flange on the
nipple, barely far enough to put a clamp on it even if I wanted to or had
So the question I have is how do you guys deal with this? Is there a tried
and true way to get that hose fully on (and maybe clamped) so that it stays
put? I am using the stock vac. hose which I have thoroughly inspected and
found to be in good shape. I know about the idea of replacing and re-routing
the hose away from it's normal path - away from the heat, but my hose is in
good condition so I have yet to have the need to do that. Is there hose
around with a slightly larger inside diameter that would more easily slide
on and then use a clamp?
Wada ya think?
Neil Vonhof
91 200q20v Sedan, 140,000 miles

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