i just traded my 1973 240 z for a 1983 280 zx he told me i need to set up the thottle position sensor. dont know how. can some one help.

We're probably going to have to start a ZX forum on this site.

You will have to find yourself a Factory Service Manual (FSM) for your car. I've got a '79 ZX so I can be some help to you, but there are differences between our cars. Check the classified section of the forums, I recall seeing a FSM for sale there.

Before you start tearing apart various peices of your car, you should probably do a basic tune up (including new plugs and wires), check ALL the vacuum hoses & fuel lines and check the condition of your gas tank.

The problem might be in there.

Search the forums for additional info. Before you start fiddling about with your fuel lines, please remember to release the pressure from the system, you will thank yourself for doing so-the directions are in the last photo.

Dark brown, not sure if this will help, but check the thread entitled "fuel tank?". My car was stalling and bucking, too. And it's the same year as yours. Just a suggestion to look at before you start getting into the high-dollar diagnostics and replacement parts.

That's just my $.02