There are probably quite a few things that could cause this, but here's what I'd
check:

1. Distributer - I had a similar experience on a non-VW, but it could cause this
problem. One of the pieces for the mechanical advance kept flaking on me. Oh, 
did you check that your points are gapped right and tightened down?

2. Fuel Injection connectors - I had exactly the same symptoms on a type III car
with fuel injection. Turned out to be a cracked injector protective bootie that 
would let water in there and corrode the contact. Cleaned the contact and the 
problem was solved. Fuel injector connections need to be clean and low 
resistance.

3. Clean the fuel filter - less likely but you never know.

Missing is probably ignition/electrical system-related. Next on the list is fuel
delivery system. Way down on the list would be heads/valves, IMHO.

Good luck,

Erik

In message <m0s3FNG-0001oSC@skypoint.com>  writes:
> I've got a 2.0 liter with fuel injection and am wondering if anyone can help
> me.  The engine seems to run good (I just put this engine in about a month
> ago), but it misses occasionally.  It will work fine for a while and then
> all of a sudden miss badly at certain rpm's and loads.  It seems to miss the
> worst at a medium load in middle rpm ranges.   ?????
> It has a new cap, rotor, and spark plugs.
> 
> I noticed in the new Hot VW's there is an article about type IV heads and
> the valve seats loosening up.  Has anybody had that problem, and what are
> the signs of it beginning.  In the article it says the engine will sound
> clanky or bang and there may be a loss in power.  Are there other symptoms?
> 

NSC Analog Automotive Systems  Tel. (408)721-3476  Fax (408)721-8292  M/S C2611