OT-Digifant Jetta Question

[rfkellner at snet.net (Rick Kellner)]

My DD, a 91 Jetta 1.8l Digifant, has an annoying running problem.  It
will stumble or stutter at low RPM when you first give it some gas.
Basically, if the car is idling and you give it a quick tap on the
accelerator, it will run rough and stumble between 1k and 2k rpms.  It
acts like a carbureted car when the accelerator pump on is the way out.
 
Any ideas?
 
Thanks, Rick K.