white smoke from exhaust, black soot buildup, and rough rpm on acceleration
 

Hey guys and gals, I've been having an issue with my car and was hoping yall could help me out here. I drive a 2003 350Z Touring fitted with a Procharger Supercharger kit. I've been looking around on the forums of multiple sites just to at least get a pinpointed direction of what the issue might be, and so far my money is on that it's running rich... Luckily, the 03's weren't fitted with a wideband O2 sensor, so getting an air/fuel ratio is a no bueno in my position. I've been using the Torque app for Android and even though I don't fully trust the measurements it displays (since I haven't been precise in fully configuring my car's profile) I do trust the freeze frame and test results it gives from the ecu, like voltages and whatnot.

So far, these are the issues:

1.) Rough rpm on acceleration (@ approx. 2500rpm and separately at 3000rpm)

2.) Black soot from exhaust on warm up; evidence of black exhaust debris on bumper picture below)

3.) Never stalls on its own, but it feels like there's a loss of power (butt dyno may be inaccurate)

4.) White smoke from exhaust
- Smells like sulfur and gas (does NOT smell sweet, coolant levels are fine, clean, and oil cap has no indication of coolant; I removed the upper and lower plenums recently to change the spark plugs and there was no evidence of coolant)

**Please note that the smoke is always present, not just on warm up. No smoke is present when cruising, but once it's WOT, I look like I just smokescreened everyone behind me. (James Bond, baby)

5.) Switching to neutral while rolling to a stop from >20mph, rpm tends to drop low (around 500rpm) and then bounces back up to normal idling range (approx. 850-900rpm)

6.) Oil light flashed on then off (number of times flashed unverified), so this might be an indication of burning oil (considering I just changed my oil roughly two weeks ago) it just started flashing yesterday, but the one time it flashed I didn't catch it in time to see how many times it flashed.

**update** I pulled the dipstick out and the oil is blacker than dead space, so it could be running rich.

7.) I just recently changed the spark plugs. The problem was occurring before I changed them; I did feel a better response from the car after changing them(typical), but the problem still persists.

Here are some pictures I took along with screenshots of O2 sensor voltage values at idle as well as this other thing I have never heard of but I felt might be important, called the Rich to Lean Sensor Threshold which was displayed as NOT OK on the torque app

https://i.imgur.com/geikRwJ.png

https://i.imgur.com/W4lYr7m.png

https://i.imgur.com/GVAvSSn.png
I ran my finger across so yall can see the contrast of bumper to black soot

https://i.imgur.com/httdCa3.jpg


Anyways, if anyone has a clue as to what the core problem might be, please let me know! I'm officially at a loss and need someone who has more knowledge than me. Thanks again, everyone.

Oh, I also forgot to state that I'm currently running stock. I pulled the belt off of the supercharger since I kind of figured it would be a bad idea to keep it on...

Alright, no one answered on here but I did find out the problem in case anyone ever has problems like these. Turns out the piston ring in cylinder 4 is fried, so I'll be heading for a engine rebuild with some new, sweet, sweet tasties going in :icon21: . But ya, so if anyone has these issues, I'm really sorry. But hey, at least have a great day. If you're in the Orange County area and plan on doing anything engine-wise, let me know. I might have a good recommendation for the price.

I have a 2003 350z Enthusiast, original owner.

So I came across around the same issue. I just finished installing; ngk colder spark plugs, unorthodox stock size pulleys, skunk2 plenum spacer, injen cold air intake, mishimoto radiator and fans, oil catch can, dc stainless steel headers and invade gemini exhaust. The vehicle is running good it just smells like burnt marshmallows and there is an abundance of white smoke coming from the exhaust, like you said seems like you are smoking out everyone behind you. I also have not really driven the vehicle for a good amount to break it all in.

Vehicle still needs to be tuned, which I will be going in 4 weeks to the local Zspecialist. I am hoping that the tuning will correct the issue.

Maybe you you know of something else other than the piston ring being fried.