2008 maxima. Car won't always start
 

2008 Maxima. Car run perfect then out of the blue go to start it and won't start. No juice to fuel pump. Been through the crank and cam sensors change both as well as fuel pump relay as well as the fuel pump and filter. Not dummy when comes to cars but this is blowing my mind on what the problem is I can't figure it out. After car sits for a couple days can go out turn key and fire right up. Run perfect no check engine light will be fine for a week or two then go to start it and nothing. Cranks over just fine has sparked just not getting fuel

POSSIBALY A COMPUTER ISSUE? sorry for the caps

Replace the ECU relay before you do anything else. It's only 30 bucks or less, so just do it. That effin' part cost me almost a year of nightmares a while ago.

Maybe this is a long shot, but it just could be your I-Key unit is failing. You won't get a check engine light for that, and it can only be scanned by a high-end tool. When next the car refuses to start, check the security light whether it's off or on when the ignition is turned to the On position.

So I decided to take another shot at my 2008 Maxima that has been sitting and basically now what I am running into is I have power to the fuel pump which is brand new as well as all new relays Cam and crank sensors and many other things. Have power going to black and yellow wire but doesn't seem to be getting a ground to activate the pump but when wire directly to battery both hot and ground car starts up and runs fine.
any suggestions????

Check your battery ground strap.