I have a 2002 Nissan maxima that was given to me, previous owner swapped a 2005 vq35 into it using the 02 transmission and it has no spark and when it did run it was very hard to start. it would start after counting to 3 while cranking and now it wont start at all and has no spark, I need help!!!!

 

There are many, many things to check. Do you have tools and work on cars?

Have you connected an OBD code reader and checked for trouble codes?

You could have a bad crankshaft sensor or a bad camshaft sensor. The ignition relay could be bad or maybe you have blown a fuse or 2.

A remotely possibility is that the timing chain jumped a tooth on the gear.

Can you check stuff like this?