Is there still a warranty on the distributor? If so, I would swap it out. Aftermarket distributors are notorious for early failure on Nissans. The crank position sensor is on the top/driver's side of the transmission bellhousing; they are a real pain to get to, especially on 4x4 models, but they aren't as prone to failure as the distributors. It probably wouldn't hurt to just check the basics first....fuses and battery cable connections...burnt fusible links...rodent damage to wiring. Of course, if you want to fix it correctly, you would need to consult your Nissan factory service manual and go through the diagnostic steps for a "no start/no spark" condition. Nico Club's site has downloadable manuals available and NissanHelp.com has some downloadable service manual chapters.