2005 G35 Coupe (VQ35DE)
Hey everyone just looking for some input on how I should go about diagnosing this rough cold start I'm having. It cranks up the first time still but the startup is getting rougher every day. As of right now, I have to crank for about 4 seconds before she fires to life (no throttle input needed).

The car has no idling issues, no misfires, no CEL, and runs fine cold or warmed up, and starts up right away if warm.

This is concerning to me as I'm getting tuned on June 22nd with AdminTuning and want the car to be in optimal mechanical condition before I start the tuning process.

The spark plugs were all replaced about 3 months ago (I also pulled them all out and checked each one a couple of days ago)
The fuel pump & fuel filter were replaced about a year ago
MAF has been cleaned

What else should I be checking? Any input would be amazing stress is at a high right now in my life

 

Check for hidden codes, you might have a crank or cam sensor on the way out. Long crank is a symptom of a failing CKP / CMP sensor.