Honda Civic speedometer bouncing
 

Just finished installing a VX transaxle into my '96 Civic HX. I have high hopes for an improvement in my freeway cruising fuel economy. One problem I'm having is the speedometer is occasionally bouncing or not working at all. This is an intermittent failure and usually happens when I first start driving the car. The first mile or so and occasionally during the middle of a drive. Speedo was working fine before the transmission swap. Anyone have a suggestion of what may be happening to cause this?
Thanks in advance.

Black Widow's used to do that every time it got cold outside (about one week out of the year). As soon as it warmed back up it would quit doing it. I never did track down the issue, and now occasionally it still does it to my son, who bought the car from me.

Well I finally had time to investigate this situation. I removed the speedometer sensor again and took a closer look at it. I noticed some corrosion on the terminals. I tried cleaning them but noticed the center terminal was nearly corroded off. I swapped the speedo sensor out of my other HX and speedometer worked fine. So my speedo sensor was shot and causing the bogus readings. Guess I'll be off to the wrecking yard tomorrow.

Update; Civic HX with VX trans. After fixing the speedometer I had my first road trip of about 150 miles of mixed driving. Trip consisted of about 3/4 freeway driving @ 70MPH, 20-30 miles back roads & small towns and one 10-15 minuets of stop & go Freeway traffic. My fuel consumption was 45.7MPG. A small sampling (150 miles) but encouraging none the less.