fd3s_rx7

iTrader: (13)

I notice the other day when I WOT I see black smoke flying off from my exhaust.

Is it good or bad sign for FD.

Mods:

Petitt Fuel Computer that was remapped to run rich.
HKS exhaust
Downpipe
intake

Thinking could be running rich that's why???

cloud9

iTrader: (4)

it's probably just a bunch of carbon build up from your motor, it's good to clean it out and going WOT is pretty much the best way to do it

jdhuegel1

Nothing to worry about. Just a little carbon and fuel..

fd3s_rx7

iTrader: (13)

yeah I figure.
Compression did turn out good. Guess I'll just have to start premix and WOT more often, because I normally shift at 3 to 2.5 k rpm. that's prob. why.

cloud9

iTrader: (4)

yeah I drive like that most of the time too, I'm always shifting before 4K, I get it on the highway to clean it out on the weekends though

gdnimr0d

iTrader: (4)

hmm thats wierd i never get that and my car has been premixed for quite some time now

ijneb

If it does this everytime the engine revs high, with the same amount each time, then I doubt its carbon. I'd bet its fuel.

JONSKI

Why did you remap the stock ECU to run rich? It already runs considerably rich.

Mahjik

iTrader: (1)

I think he just means he has a Pettit ECU.

fd3s_rx7,

ijneb is right. If it's happening ALL the time you step on the gas, something may not be right. If you only see it once in a while, it's probably just carbon build up.

fd3s_rx7

iTrader: (13)

yeah Mahjik is correct. I have the Pettit ecu not my stock.

and yeah it only happens once in a long time.

jdhuegel1

Premixing would not cause black smoke.

chiminoid

all smoke = bad

jdhuegel1

Please elaborate.

JONSKI

I thought the Pettit ECU was a re-chipped stocker.

pito13b

iTrader: (3)

My car smokes all kinds of colors. WOT, its gonna be fuel. I can leave a hell of a cloud.

z28_SS

My car smokes black smokes too.

Mechanic says nothing to worry about cause normal for FD to be like that.