Atjstballin

Here's the details,
1. Happens when Car is cold
2. Only under Any sort of moderate acceleration
3. Happens in all gears
4. No issues when idle
4. after like 30 seconds of sputtering, the car is perfect,
5. No codes.
Mods, high flow cats, z1 single exit exhaus. Nismo intakes, everything else stock.

car has 53k miles, I'm looking to change spark plugs maybe they are having an issue when cold.🤷‍♂️

Any ideas? 😂

travlee

iTrader: (8)

i would check for vacuum leaks

Atjstballin

I hear a light popping sounds near the top centerof the engine when cold. Do you think that could that be a vaccume leak?

icer5160

iTrader: (4)

You could have a vacuum leak, weak fuel pump, faulty injectors, or faulty coil packs. Another possible fault could be the cam or crank sensors, but unusual to see these go on a vehicle with only 53k mi. What year is the Z? Is this a DE or HR? I'm guessing HR since you said Nismo intakes (plural). I would try to smoke test your intakes, check for any signs of a leak. But before going any further and guessing, get a OBDII scanner on the car and check for any pending fault codes. With the type of issue you described, I would imagine the CEL to be on.
-Icer

Atjstballin

Yeah its an HR, I can hear a small very inconsistent tick sometimes with what also sounds like whistling (especially when cold), just cant pinpoint where its coming from yet. I would assume an exhaust leak could have for the car to run like this when cold, then expand as it gets warm, resulting in the issue going completely away?

bre240z

check the coil packs. You can disconnect one by one and if the idle does not change that coil pack is no good. Had something similar to this happen to me and it was a coil pack. Service light was not even turning on. Finally i put a scanner on it and sure enough one of the coil packs

lifekenophobic

When you feel the sputtering/hesitation, try mashing the throttle to see if that makes it stop. If so, congratulations! You get to spend $1,000 on new VTC covers like I did a few years back. Apparently quite a few HR's have this issue.

I hope for your sake it's as simple as some of the other suggestions that everyone had, if not I recommend reading my post here: https://my350z.com/forum/maintenance...l#post10886135

icer5160

iTrader: (4)

I hope phobic wrong! I would think it really strange if your VCT covers crapped out at 53k mi. Typically these last a really long time unless running with extended oil changes (every 10k mi or something). Change your oil often on these cars! Manual states every 3750mi for my 06. I do it every 3500mi. Oil is cheap! Engine repairs are not!
Cheers!
-Icer

lifekenophobic

Mine took a dump around 95k miles, and I change my oil every 3k miles with Mobil1 synthetic. Replaced the covers 5 years ago and haven't had one performance issue since.

It's kinda like gallery gaskets for the HR. Some people might have them fail at 50k miles, some people might not have any issues at all. Just luck of the draw. I do know the magnets in these VTC covers are very sensitive, and I believe that's the part that fails.

icer5160

iTrader: (4)

Wow, guess it's just luck of the draw. I can't believe how expensive the VCT Covers are. Fingers crossed I never run into this issue on my revup DE.
-Icer