What's up with my speedometer when I start to accel hard and it jumps out to 120 then back to the real speed, and continues doing that until i level out?

 

must be an older (93 or before) Integra w/ a speedo cable. If so, lube the cable w/ some graphite lube (in a small tube). My Camry and my friend's old 3rd gen Prelude used to do that, but graphite lube cleared it right up.

 

had a 94 gsr that did the same stuff.Tach would go crazy also.Ended up a surge protector in the bottom of the under hood fuse box.Had to replace intire box to solve the problem.I hit the junkyard.

 

speedo cable....only like 30 bucks at ur local acura dealership