Wacko Speedo?

[Bob Greene <rgreene@whoi.edu>]

Hi LisTeRs:
    Here's a new one (too me anyway). 1979 Spitfire. The speedo seems to 
work fine, with the one exception. While driving down the road it works 
well, when you put the gas pedal to the floor, the speedo falls back to 
zero. If you let up slightly on the gas pedal, the speedo come back up 
to road speed?
    Any ideas?
    Bob Greene
    76 TR6 & 79 Spit
    CCBCC
    www.capecodbritishcarclub.org