Also, if you don't just happen to have the stuff for adjusting the valves, take it to any VW mechanic, the shims are the same for all the old VW water cooled engines.

And it would also be a good idea to completely drain the fuel tank to get any settled junk out and refill with fresh ( your '82 may or may not have a drain plug on the bottom of the tank, if not you'll need to hook some kind of electric or drill pump on your fuel line and pump it out).

How much blow by does it have? If you pull the breather hose does it puff out hard? is there oil residue on top of the air filter element?

Also if pump timing is off( too far retarded) you won't haev any power. if it has had a timing belt done by a general mechanic, chances aer the timing is off bad..
You should really have the tools to do it right , but if you mark the position of the pump with a marker etc, then experiment with advancing the timing a small amount and se what happens, you can always put it back..
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-------Robert, '93 940t, '90 240 wagon, '84 240 diesel (she's sick) , '80 245 diesel, '82 Mercedes 300SD