I'm new to all this but need to figure it out so I can figure out how to fix my car.
 

I am new to all this. I hope you all will have a little patients with me.
I have a 2007 Infinity G 35 coupe 6 sp. Mtrans. And I can't wait to.get it going. Im having problems getting it running. I bought it from a dude that said it was in good shape. He lied! Rod knocking! So.i pulled the motor and spent a week polishing the rod journal of the knocking rod. New bering and put it back in and it started ran a little and quit. Cranks but no fire. I changed the crank sensor and got it to run a little about 5 min. So i went to the wrecking yard cuz im broke and got a few sensors. Put them in and now its a no start at all. Fuel pump isnt priming and im thinking new crank and cam sensors so i ordered new ones. I put a fuel pump from a wrecked g35 in but no prime. Could it be that the crank sensor and cam sensors are not letting it start or no fuel pump prime? Anyway i had the locksmith come here today and he says the ecu is not communicating with the key. SO HERE I AM ASKING FOR HELP PLEASE I can wrench I just need advise on what to do now? Anybody want to help this old guy out? I would appreciate any help please as long as you know these cars. Thanks

It can be a long haul when these things don't work..keep your chin up.

Are you getting any check engine lights?

The fact that you had it run for 5 minutes says, to me, that the key and ecu are ok.

You need to buy a forseal wifi obd2 connector from amazon and download the Torque pro app down to your phone.
This way, you can talk to your own damn car and run diagnostics and read codes.

This is step one..otherwise you are just going to be replacing parts by guessing...i.e shotgunning parts.