[200q20v] Great Acceleration until "Brick Wall"
hah at srv.net
hah at srv.net
Mon May 21 15:09:00 EDT 2001
>Oh wise ones...
>While on a modest 100+ mile trip I encountered several instances while
>accelerating of "bucking, erratic engine behavior". This happened both
>during "hard" acceleration and occasionally when the cruise control
>would attempt to adjust the speed (appx 85 mph, 22 mpg). The engine
>compartment fuel filter has about 5K on it and about 120K on the
>engine/vehicle. I usually run 93 octane and suspect the fuel pump (gas
>tank). No other symptoms of engine problems. Are there any other
>filters that may be restricting fuel flow?
I had a severe bucking problem after filling up with 91 octane (the
"premium" available at that altitude) that I strongly suspect was crap
(technical term). This was pre-chip, first time after I filled up that I
exceeded 1.4 bar on the dash gauge - huge bucking, I thought fuel
filter/pump too. No, just extreme detonation, very very bad. No problems
the rest of the tank as long as I was very unleaded with the right foot -
and I was! Probably illegal to so badly underperform advertised octane
rating, but it was all the way across the state and I seem to have escaped
without permanent damamge...
If the bucking isn't so severe, it could be a sign that the mass air flow
sensor (hot wire) has died (or the Motronic thinks so) and you are
operating on best-guess limp-home mode. Others have documented this in the
1991 200 quattro, 112k, picky eater
1988 GTI 16v, 218k, happy with regular
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