Decel valve

[Block, Paul]

Hi folks,
A couple of easy questions.  
Is a sticky decel valve fixable?  I'm assuming it's not as Bently says to
replace it and I couldn't find any fix-its in the archives, so I'll ask the
second question.

Does anyone know the part num for the decel valve on an 89 200q
(WAUGC0449KN004876).  I included my vin because I was told that there are
two different ones for the car.  Is one supposed to supercede the other?  Do
they actually work differently?

Thanks a bunch for the info.  I am trying to get this ordered and fixed
before the weekend, but the last couple of days, I haven't had time to take
the old one out to get the pn.

Thanks again
-Paul