My 93 nissan altima stalled while driving and will not start back. put on a new coil, new fuel pump. still will not start. is it the crank sensor or distributor?

First, verify all connections at distributor (both ends of each cable) are securely connected and inspect all lengths of each plug wire to make sure there are no major breaks, cuts, burns, abrasions that would be causing a short. Then, try another plug just to make sure it's not a bad spark/coil wire. If still no spark, then I would say rotor/distributor cap/distributor/ICM module (Ignition Control Module) is the problem. You can generally buy those parts seperate, or you can buy a whole distributor that typically has all combined. The ICM can usually be removed without too much difficulty and taken to an autoparts store for a test, but not always. If you go with the "piecemeal" solution, start with ICM test (if removable), then rotor cap, then move to distrubutor cap. If nothing has worked to this point, you can replace the distributor, but you have already bought everything BUT the actual distributor. It would make sense to price everything seperately versus cost of new distributor...up to you.

If you do replace the distributor, be absolutely sure to mark the position/direction the rotor cap is pointed on old one, so you can re-install the new one in exact same position. Otherwise finding TDC (top dead center) on #1 cylinder is another whole process.