I put the SGI 5 box in my 91z28 after my t56 swap and now rigth after I start my car, my speedo read between 100 and 130 MPH. worse part is my odemeter racks up miles too. it will work after I take off but when i come to a stop the thing is pegged. anyone have this problem.

 

Have someone read the installation sheet for you, especially the part about the DIP switch settings.

 

Kevin you trying to be sarcastic or something. For your information I do read instructions and the box is hooked up correctly and the setting have alrady been played with.

 

If you are sure that you installed it correctly and you set the switches correctly, then I can only think of one thing. I don't remember which two wires exactly, but I think the ground wire and the wire from the vss(not sure) need to be twisted around each other to eliminate interference. I doubt this would cause your speedo to jump all the way to 130 mph, but its all I can think of.

Mine has been working fine since I installed it, no problems at all.

If it makes you feel bad that you are racking up miles on the odometer when you aren't moving, just drive around without the conversion box connected.