Godzilla

Black soot on acceleration – otherwise tuned dead nuts…need suggestions please..

My 408 CI stroker is dead nuts on the ltrims ( -2 ) , KR (<.5) and WB A/f (13.1) yet on acceleration I get black soot and for an instant it looks like diesel

Help! Any suggestions on what to do…is it my early PCM? (98)

NoGo

iTrader: (2)

Try changing your WOT settings. Set an RPM delay in your PE table. On the 98 you should be able to do this.

Black LS1 T/A

Or, adjust your PE/RPM settings in that RPM range where the richness occurs. ?

WAHUSKER

iTrader: (4)

Do you have a Greddy Catch Can (or similar)? that might solve your problem. I hear many people complain about the puff of smoke when they first nail it, and I would guess it's due to the oil that collects in the intake / tb area from the PCV.

Another_User

If you are referring to black soot that comes out at high rpm, it may be normal. Soot builds up in your exhaust, and it will come out at high RPMs particularly at WOT. Otherwise if it is blue smoke you cuold have blown your valve-guide seals. Just a thought.

billc5

iTrader: (1)

I took the magnacharger intake manifold off this winter and found what I thought was lots of oil laying in the runners, they tell me that this is from reversion picked up from the valve guides. Since Ive never notice any oil consumption this shouldnt be a problem.

My tail pipes had excessive soot and looked like Hell (I tried in vain for months with LS1_Edit). I changed the new 39# to 42's and magic no more soot. I cant tell you why but this was a used set that took all of 15 minutes to change and a few more to calibrate and I now have a shinney exhaust.

Black LS1 T/A

Black smoke is fuel
Blue smoke is oil
White smoke is water/condensation

Godzilla

Thanks for the replies. I am going to change out the injectors because I never have any blue smoke - only black -