I vote for a plugged catalytic converter or a disintegrated one that has plugged
the muffler.  Had the same problem with my '83.5.  Took a punch and broke out the
remaining cat matrix, emptied out the pieces, emptied out the muffler put it all
back together and the problem was gone and the power was back.  It even passed
SoCal smog.

Good luck,

Jim Arnott
Union, OR

Dentonair wrote:

> Here is my question:  The VW engine rebuilders just put my engine back
> together
> and said that everything runs great but........the top end speed "is not what
> they expect out of a new 1.9L engine.  They have swapped off every part on the
> engine to see if anything would give it that extra umph!  No luck.  It has new
> fuel injectors, belts, idle stabilizer, 02 sensor, clutch, water pump, and air
> filter.  The exhaust system is very tight (new cross-over pipes too).
>
> The shop told me that the engine runs better when the temp sensor is
> unplugged?
>
> The only thing that I can think of is a dirty fuel filter (I havent changed it
> yet). Could this be the problem?  If not, does anyone have any ideas on where
> my top end power is going?
>
> Thanks for any help you can give.  Thanks, Jason  (Everett, WA)