wfritts911

iTrader: (2)

Ok so i got my car dyno'd last week and i noticed that when it got close to the redline that it puffed out a bit of black smoke. Didn't see it any other time but just before it redlined, would this be because the computer about to shut it down and its not a big deal? Or because the PCV system was blowing by? 98 LS1 M6 just flowmaster muffler by the PO. Oh and wheres the best place to get something to do a leakdown test with? Thanks

-Will

IH8EVRY1

iTrader: (5)

Black smoke is normally a symptom of a rich fuel mixture. If I remember right, at WOT the computer is adding fuel to prevent a lean situation. If you have any leaks where extra air is getting in and the computer is reading that it will also dump extra fuel because it thinks you are lean.

Did the guys running the dyno say anything out of the ordinary? Was the car hooked to anything to read air to fuel ratios? If the guys at the shop didn't say anything I probably wouldn't sweat black smoke.

roach4047

My ride did the same thing on the dyno a couple of pulls back to back. No body at the dyno seemed too concerned. One guy commented..."it looked like fuel to me."

Roach

SWEET98SS

iTrader: (8)

Mine does it also. I have a cutout, maybe it tries adding extra fuel for it thinking its a leak.

jeremyjones

my brothers car smoked everytime he went wot. but his rings were gapped for a 250 shot. ur is prolly fuel

wfritts911

iTrader: (2)

ya guys at dyno guy said it ran really good, and it didnt do it anytime but right before redline so i wasnt worried. Just curious and yea it had an o2 at the tail pipe but they didnt say anything was wrong so im sure its not a problem.

-Will

Duffster

iTrader: (103)

just blowing carbon out. . .