s13 HUD Speedo shows i'm moving on cold start while parked?

[cobrarstreetracr]

I tried searching the forums for this problems, but came up empty handed, maybe i had the wrong search terms, but if this question hasnt been answered before, heres the problem:

I have been having a problem with my H.U.D in my 91' coupe with an sr20det. Every time i go and start the car after i havent driven it for a while, like over night on a cold start, the speed on the HUD and the dash bounces around to random numbers (normally between 0-10 example: 4, 8, 6, 10, 0, 2, but it has read as high as 30 in rare situations) but all of this is while sitting still at idle on cold starts. Once the car warms up it dose just fine and it dosent do it again till the next cold start. Has anyone else seen this problem or had this problem? The idle doent bounce, just the speedo for some reason while i am parked. Just not sure what would be causing this. This car came from the factory with the hud so it wasnt a retrofit if that narrows anything down. Thanks in advance!

[cobrarstreetracr]

Anyone?!?!

Even if you havent seen this let me know. That way i can at least know its something new and weird.

[biggie]

Never heard of it.

Possible that the speed sensor is the issue?

[blacksrjdm]

I dont know that that is that weird. Electronics do funny things when in cold temperatures. But be sure to check the harness going to the speed sensor, make sure that it is intact.

[cobrarstreetracr]

hey thanks yea i am going to check plugs today and maybe try to insulate the plugs or harness so it dosnt get so cold and see if that helps.