My gf's 91 accord randomly drops the speedometer to 0, the sport light flashes, and sometimes the check engine light comes on...... it happens when she accelerates too fast most of the time. What could cause this? i was thinking a sensor?

 

Have u checked the speedo cable

 

check the code; it sounds like a VSS problem.
Here's a link to help you ;
http://members.troublecodes.ne...n.jpg