I read all of the forums with everyone's problem with there 24z engines reving out around 2500rpm. Has any one figured this out yet?? I just bought a 86 model that's doing it. Has a 23 and 24 code. Done all the basics but no change. HELP!

You're in the wrong area but I'll try helping and then move to the correct area. On a Z31 code 23 is a TPS, which can limit rpm, this is where I'd start. if the tps checks out ok, often a bad MAS can lead to rpm related issues.

Check the ground wires on the block and chassis while you're at it. I think 23 is Idle Switch and 24 is Throttle Valve Switch... those two are part of the same sensor, being the throttle position sensor. So, you likely need a new one installed and then you have to twist it to the right spot to get the proper voltage/ resistance.