bucking above 1.1 bar, max boost 1.3

Kneale Brownson knotnook at traverse.com
Mon Feb 25 06:33:10 EST 2002

My bet's on the fuel pump.

At 10:42 PM 02/24/2002 -0500, Chris Covington wrote:

>I took a nice trip this weekend to Burlington, VT to visit a friend and
>give the 200 a nice 200 mile each-way trip.  No problems on the way there,
>in fact I even got 23.8MPG.  On the way back, merging/passing a Volvo
>after the I87 onramp in 3rd gear, at around 5K RPMs at WOT the 200
>seriously bucked and I let off the throttle.  The engine ran fine as long
>as it didn't get over 1.0 bar, without any missing / roughness, then it
>would buck really hard as if it were backing off or intentionally
>preventing high boost.  I let off boost for awhile then I then pulled over
>to get gas and check the intercooler hoses, and everything seemed fine.
>After the fill-up on 87 the 200 seemed normal again - I still got 1.7-1.8
>but I didn't push it too hard because I was more concerned with getting
>When I got home I tested it again and basically now get serious bucking
>in any gear starting when boost gets over 1.0 bar, with 1.3 being the
>highest I can get.  I thought it might've been the WOT switch because it
>seemed to only do it at full throttle, but under further examination it
>will buck at 3/4 throttle too, or in any other situation in which it goes
>above 1.0 bar.  So it seems to be a boost issue (or the witholding of) of
>some kind.  All my hoses are either new / in good shape.
>Is this the WGFV?  Something else?

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