i was driving my civic down i-264 when i looked at the speedo to check how fast i was goin i noticed it jumping arond and then it went completly down so i just kept driving and then about a mile or two the needle jumped back up.

what could cause that?

 

Bad ground for electronic speedo's

 

you need the speedometer piece in your cluster replaced.

 

What year? Any CEL codes?

 

I kinda have a simlar problem. mine sits at 30 kph untill i drive abitthen it snaps up to normal. I am goign to test my wires for shorts i will let you know if i find anything.

do you have accses to another cluster to put in to see if thats the issue?
keep us posted

 

a short, bad ground in the system, could also be a speedo sensor going out. one of my old cars did this and it ended up being the speedo sensor

 

i'd check the speed sensor on the tranny and clean it, see if that solves the problem. This has happened to me before but it was because I had a y8 speed sensor in a GSR tranny