Re: 1983 280zx Won't Crank or start
Power steering fluid has indeed destroyed one alternator that I know of, from a year or two ago on this forum. Alternators really don't like foreign crud inside them!
You need a good battery with a full charge. It needs to be at least 12.5 volts at rest, and it needs to not drop below about 11.5 volts while cranking the starter. If your battery charge is too low, or the battery won't support the power drain during start, your ZX won't do much for you. If the battery gets too low, the injectors won't inject, the spark system won't fire, the fuel pump won't pump enough, et cetera. Note that those voltage measurements MUST be taken, with a decent volt meter, directly on the battery posts. Do not depend on the dash mounted volt meter. It is not accurate enough.
If the filthy alternator has been taken out by the PS fluid, then you have been running on your battery, and that can only take you so far. If the battery gets weak enough, you can't even push start the car.
Also, use the ohm meter function of your multimeter to check your fusible links, especially the black one. That is the one that brings freshly generated +12 volts to the battery and the car. If it is blown, the battery will eventually be discharged, even if the alternator is actually good.
Download a FREE copy of the original Nissan shop manual for your car, by clicking on the appropriate link in my sig. There are lots of troubleshooting tables and diagrams, things for you to check. If you carefully perform them, you might even fix your problem!