Weird jumpy speedo

[a80crewza]

Hi all. My speedo bounces back and forth a tiny bit at around 3000rpm, its hard to notice. Doesn't do it all the time, and have only noticed it when going high speeds (80-100ish). Seems to come in just before gears change from 3rd to 4th (1kz auto). I just installed a manual boost controller.. Any ideas?

Cheers.

[skid]

may last a year

may not

eventually it will just stop working all together

mine was doing the same till it stopped working, been that way for over 4 years now

[a80crewza]

So its just an ageing gauge Will just have to use the car in front as a speed gauge

[tweake]

some of them are quite prone to corrosion on the speedo boards and dry solder joints. fairly easy fix.

[Dirtydog]

just use a gps, easiest way to tell what speed ya doing...

[Ollie_216]

I had a really jumpy speedo on my '94 Surf, would sometimes sit on zero then go to 80 when I was only going 50. Was caused by the sun heating the top of the dash and speedo circuit board, it just melted two solder strips together on the speedo circuit board. I just got a nail and scratched between the two to break the contact. Easy 30min fix with no cost, if that's the problem..

[a80crewza]

Okay, so I started my truck up this morning and the engine revs up and down by itself? Seemed to go away when it started to get warm. So it's not the speedo? Could it be avacuum leak??