Where is the starter on a 1990 Nissan stanza?
Look at the lower rear end of the engine
== == I had the same problem with my 92 Nissan Stanza XE. Turns out it was the starter. You might need to look into getting a new starter. Also, have someone check your spark plugs, plug wires, and your fuel pump. I say fuel pump because after we fixed the starter problem. The fuel pump went bad. These are great cars, you just have to take a little extra care of them.
The starter is located on the back of the engine. Support the car on jack stands and you will be able to see the battery cable that needs to be unhooked first and then unplug the starter kill switch. After that go under the hood on the drivers side of the car and you will able to take loose the two bolts that hold the starter in place.