95 Maxima 5 speed 130K

My car recently have this weird cranking noise during start up like something is banging on the engine and the RPM is very unstable like the car is coughing when the car is started the first few second it goes from 500-1000RPM back and fore for like 5 second then it start to be normal but before i start up if i press on the gas a few time then start the car the werid cranking sound goes away sometimes i have just replaced a Nissan Factory starter 2 months ago i was thinking could it be the fuel pump or the knock sensor that weird cranking sound really scare me like the car is dying out on me sooner or later does anyone have an idea what is going on need the problem to be slove ASAP THANK YOU !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

How are your belts? Sometimes these make noises when the tension aren't as tight.

 

have you replaced any of your coils?

 

i believe it's your belt...i had this sound before also when i had a 96..