So i just picked up a 93 z auto drove good when i was test driving. Went to drive it the other day start the car and the speedo just starts going crazy it started reading 60-70mph with the car at idle. i put the car in drive and the speedo reads correct when im driving. that problem 1

Problem 2- kinda hard to explain the car will run awesome quick and fast but the tranny doesnt like to shift.. and when the tranny shifts nice and easy and i give it full throttle the car boogs stumbles runs like ****.

IDK what these problems could be i was thinking VSS but thats not the case any ideas??

 

just noticed that at idle if i put my foot on the brake the speedo goes down take foot off brake speedo goes up wtf

 

The speedpometer problem sounds like a bad ground wire somewhere,I would check the connector or sensor on the trans..If the trans is slipping when you jump on it,sounds like time for a rebuild.