2003 Nissan 350z Touring

My car tends to shut off while driving when I push down my clutch pedal for too long. This seems to happen on windy days and when I let the rpm’s drop after leaving the clutch pushed in for too long. (I generally push it in when I am stopping, so I can just coast) I’ve replaced the alternator this past weekend and the battery is less then a year old. The MAF is also a little less than a year old. I have a rough idle, sits at around 640, then when I use any accessory it can drop to roughly 520 ish. It also makes a faint sucking or hissing noise while pushing on the gas at mid-higher speeds, and when I’m idle and blip the gas it makes a quick sucking/kissing sound.(I thought this was due to the cold air intake) There is an aftermarket cold air intake, the previous owner put on it. It’s a cylindrical shaped one.

I cannot figure out why this is happening. If you have any suggestions or ideas please let me know. Thank you.

Edit: Also I know there are a lot of posts about this, but a lot of the responses are saying things that I’ve already done to prevent this.

 

To prevent a bunch of responses on things you've tried,
What have you done?

 

Why are you depressing the clutch pedal when you are stopping and leaving it like that instead of shifting to neutral?

Have all your replacement parts been with OEM?

WHAT CODES IS IT SHOWING?

 

I have replaced the alternator, replaced the MAF sensor, did the idle relearn, replaced the battery, cleaned the throttle body, replaced the idler pulley (I don’t know if this is related).
No they haven’t all been OEM, but they were the right parts. But the issue was already happening on the OEM parts.
it’s not showing any codes besides B1081, B1086.
Which are, “Pre-tensioner front right hand(open)” and “Pre-tensioner front left hand(open)”.
And I leave it pushed down because when I idle and I start the car, as soon as I release the clutch (in neutral ofc) my rpms drop slightly then come back up. So if I hold it down I don’t risk killing the car more often.

 

Does your code reader do live data? Watch your short term fuel trims when it's stalling. Do they go up right before it dies? You might have a vacuum leak. Or you might have a fuel pump that's on the way out.

 

That's what I was thinking too

If you don't have a scan tool you can buy "starting fluid" and spray around the intakes/manifold while the car is idling. If the rpms go up, you have a leak.

 

min response to both of y’all; I have the BlueDriver Bluetooth scanner, so I can check live data. But I’m not too sure what I’m lookin for. The short term fuel trim? What Am I looking for on that? Im kinda new at looking at the live data so i just need a little walk through. Also could the vacuum leak be the cause of that hissing / sucking noise that I stated in the post?

 

You looking for positive numbers that indicate the ECM is adding fuel to compensate for a lean condition. Negative numbers means you're running rich. I believe the max is 25. Yes, the hissing could be a vacuum leak.

 

alright sorry about the late response. But I’ve attached the read outs for the short term fuel trims. I can’t tell if I have a vacuum leak by these numbers. But at about 4 minutes (240 seconds) I revved it to show you how it drops after the revs go down. The data also starts at about 56 seconds.