our car starts 80% of the time the other 20% it makes a click sound and does not start if we leave it alone for 10-15 minutes it does eventually start - I had the alternator, starter and battery (which is 2 months old) all tested and Sears said it was all fine - help!!

Optional Information:
2003 Ford Taurus 6 cylndr

Already Tried:
Sears diagnosis