96 nissan 200sx started and ran rough for 10 sec then died and wont restart. distributor is turning. no fault codes. has good fuel pressure. spark looked weak so i changed cap and rotor. still wont start. replaced spark plugs - still nothing.

If the spark will jump a half inch space you are probably ok with that.
My first question is do you know if the timing belt is ok ?
The second question is have you tried spraying carb cleaner or starting fluid into the throttle body to make sure you have fuel ?

Sounds like a fuel pressure problem, either the pump or the filter among other things.

check fuel regulator, fuel pressure, could be bad sending unit in fuel tank, change out fuel filter

re check spark plug wires-might be in wrong slots

it'll either be your ignition system (spark plugs, distributor cap, etc) or more likely your fuel system (most likely your fuel pump or your fuel filter)

check the cat. it may be clogged

this is a classic symptom of a defective fuel pump pressure check valve, it is not holding pressure after the car is turned off, this causes the problem you have, the check valve is part of the fuel pump and that is located in the gas tank.

First, never use starting fluid on a gasoline engine. Check for dirty air filter, then check for Mass air flow sensor (Fault code) . This sensor controls fuel mapping, bad signal here will cause over fueling (black smoke) also called loading up (rich). Stopped up Air filter will affect Mass air flow. Perform OBD II test to prevent buying unneeded parts. Also delete stored codes.

replace the distributor oil is leaking into the electronics of the distributor and shorting out pull cap back off and look and see if oil is leaking out

If the starter fluid worked for a little and the engine died again, it may be some of your filters. Check the air and fuel filters and replace them if they are dirty or haven't been replaced in a long while. This is the most common reason a car won't start.

Another idea is the engine may have been flooded. If you have a fuel injected engine, don't pump the fuel when trying to start it. The fuel pump primes the engine all on it's own. If the engine is already flooded, push the fuel pedal all the way to the floor and hold it there while you try to start the engine. This bypasses the priming and opens the air to blast any unburned fuel out of the cylinders.

Check to make sure you are getting spark with an inline spark tester (at auto parts stores) and if not try replacing (in order) the spark plugs, wires and (depending on your engine) the magneto's or distributor cap. Ask the auto parts store if they can look up if you have a distributor-less ignition or if you have a distributor.

So, first the filters (air and any fuel [there may be more than 1]) then check for spark and replace the spark plugs, wires, and magneto/distributor cap.

I hope this helps and good luck! Don't forget to rate! Thank you!