04 6mt...anybody get a cloud of blue smoke from their exhaust for about 5 seconds after resetting their ecu?? if not, what exactly could this mean? i know blue smoke usually comes from oil..thanks for any help..

 

I doubt that there's any correlation between the puff of blue and the ECU reset.
Has the engine been burning any oil lately? If not don't worry.

<font color=red>GSM</font color=red>
<font color=red>GSM</font color=red>
<font color=black>Silverstone Coupe</font color=black>

 

nope..first time i ever saw it do that...i use the car everyday..and it only happened immediately after the reset..

 

That might not be oil, but unburnt fuel. Mine let off a puff like that when I reset my ECU. It might be normal, or we both did something wrong!

"What if there is no tomorrow....There wasn't one today!!!" Bill Murry

 

were you puffing on anything before you saw the blue smoke

AKA SET ROK

 

hey atleast that makes 2 of us that it happened to..anyone else?

 

I don't know why you are getting blue smoke this early on your coupe, but the main reason why you get blue smoke is when your valve springs wear out their seat on the head and the exhaust valve doesn't seal properly when combustion happens. You might want to have your car checked out to make sure. Good luck.

2004 G35 Coupe 6MT | Premium | Aero | Splash Guards | XM Radio | Z Tube | JWT Pop Charger

 

Totally normal. I'm guessing the outside air temp was cool when you did the reset. Here's what I think happens: WIthout any historical data, and in the absence of feedback loop info, the engine initially reverts to a standardized map, using say (I'm guessing) 15 degrees C or around 60 degrees F as a baseline. When the feedback from the MAF, exhaust and other sensors detect way more oxygen than expected, the carburetion quickly richens, since a rich condition will do far less harm or wear to the engine. (remember, colder air is denser, thus has more oxygen by volume) Hence the puff of smoke for about 5 secs. In those few seconds, real feedback data provided to the system allows adjustment back to a normal mixture of fuel and air. And the smoke quickly disappears.
I did 3 minor changes on the weekend, k&n drop-in, z tube, and ecu reset. But I did them one at a time, to see their effect in isolation. Here's what I found:
drop-in: immediately crispened carburetion, especially as revs fall off after revving at a standstill. The car used to have a (pleasant) sputtery burble on rev fall-off. Now it's crisp, never seeing that temporary rich condition that caused the burble.
Z-tube (Installed at 4 degrees C, or about 38F): Smoked on initial start-up, mixture cleaned up mostly before I got out of the driveway, entirely by the time I had driven for 2 minutes. Didn't really notice a big change in volume, sounds good, noticebly more eager once the engine gets onto the cam, around 3500 rpm (makes sense, this is when the engine is wanting to breathe more fully, I got the impression that the engine isn't so stuffed up).
ecu reset (using key and pedal method)- smoked on start-up, just like when I put on the tube, same timeframe for carburetion to clean up. Seat of the pants changes: none whatsoever. Urban legend IMHO (and I'm sure we'll see a bunch of posts to the contrary, but I hafta wonder if people don't sense a change because they want to, and are expecting to.)
I did these changes because they were cheap and easy, and I was curious. I think I spent 15 minutes under the hood, total.
BTW thank you to all who have posted instructions and photos. I'm sure it would have taken longer without.

Hope this helps, nthn.

Cheers,
Derek

P.S. When I see pics of the tubes next to each other, I hafta wonder, what the H@LL Nissan was thinkin'. One is a relatively straight intake (which all theory would suggest is optimal). The other costs a bunch extra to manufacture, more effort to install (one extra clamp), modification of the engine modesty cover (cutout for the OE G tube) for no apparent gain, other than allowing the Z to claim 7 more horsies. Frustrating and irritating. (Sorry for the rant, I feel better now)

DB

 

This winter when it was colder than heck, every time I started mine it would blow a real thick blue smoke for a sec. Was nasty but hasn't done it since the weather has been nice. Weird...

2003 BLK/BLK 6-spd Injen clear corners