high fuel consumption / cold start / rough idle

[yurple at hotmail.com (Mark Malowicki)]

Hello!

  I have a 1983 Scirocco with the 1.8L, and a while back it started having 
cold start problems.  I checked the thermo time switch, cold start valve, 
and aux air regulator, and they all checked out fine.

  Then, recently it started having rough idle problems -- drops down a few 
hundred rpm, shudders, then recovers, drops, recovers, etc.  It seems to run 
fine otherwise.

  AND THEN, this past weekend I noticed the fuel mileage has gone way down 
-- I usually get ~33mpg, now I'm getting 23 or so.  I rechecked the cold 
start valve, but it still checks out ok -- sprays fuel when cold, no leaks 
when warm.

  What could explain all of these symptoms?  Warm up regulator???  I checked 
the resistance across it, and it's OK, at 16ohms.  Any suggestions?

                                                       - Mark