The 2700VV was completely different from carburetors previously used on US Capris. Instead of the usual main jet - emulsion tube - air corrector system, vacuum operated metering rods regulated fuel flow through the main jets. The most radical difference was the slider plate at the top of the carburetor, where the choke would normally be found. This housed the oblong variable venturis, and it replaced the normal fixed venturis and the choke valves. The slider plate would move back and forth in response to engine vacuum, altering the size of the venturis. This was supposed to simultaneously provide good response at low engine speed, and good high RPM power. Fuel was also could be metered more precisely over a wider range of conditions, which would allow good performance while maintaining low exhaust emissions and superior fuel economy. All of this looked good on paper; indeed, Carter successfully used the metering rod system on its famous four barrel carburetors for many years, while the slider plate was conceptually similar to the damper in "constant velocity" carburetors like the SU. In practice the 2700VV was mechanically complex and tended to be unreliable. The slider plates had an unfortunate tendency to stick as they aged, which of course adversely affected performance.
The 2700VV was also more difficult to service than previous carburetors. Service procedures were complex, and many special tools were required; most backyard mechanics, independent repair shops, and even some dealer service departments simply didn't have them. This meant that when a 2700VV needed adjustment or repair, it was maddeningly difficult to find someone who could do the job properly.