The Nissan Path

Alright. Long story boring, this is not my rig. A friend hired a meth head to change the oil pump (why? I don't know.) and the dude muffed everything up. So after four days of correcting everything he ruined I got the engine together, plugged everything in...aaaand the engine won't start. Yes it turns over, and yes the fuel system is working. I haven't got around to checking spark yet though. I suppose I'll try it tomorrow. Let's assume for the moment that it does have spark.

So...WTF? What are the chances that it could be the crank position sensor?

Well, if it does have spark, it's not the crank sensor. I would spray carb cleaner into the engine and see if it fires. If it does, then you have a fuel system issue.