JNorris

iTrader: (4)

I am hoping you all can give me a few suggestions that might help me determine why I have black smoke at WOT.

My mods are listed below:

TEA stage 1.5 5.3L heads milled .015
TR224/114 cam
Stock length push rods
Stock (factory) timing chain
LS6 intake
30# SVO injectors
Mac headers
Ported TB
De-screened stock MAF
Fast Toys Ram Air kit
ASP pulley
Built 4L60E with a PT4000 stall converter

I use EFILive, Innovate Motorsports WB O2 meter, and LS1Edit to tune the car.

LTFT are between -.8 and -10 while at cruse and 0 at WOT.
WOT AFR bounces around between 12.7 and 13.1 depending on what gear and RPM.

My AFR looks good. I have confirmed proper operation of the WB on other cars.

I know black smoke is not always an indication of a rich condition. It can also be an indication of incomplete combustion.

Any suggestions?


Thanks

John

monodax

How long does the black smoke appear @ WOT?

JNorris

iTrader: (4)

"How long does the black smoke appear @ WOT?"

Until I let off the gas.

TA2SLOW346

iTrader: (3)

Do a WOT run and at top of 3rd kill the ignition and do a plug reading. reading the plugs might tell you something other then what the wideband is telling you. You might find one cylinder different then the rest also.

DarDaug

I have a 2001 Trans Am and I was having the same problem. I have some minor modifications such as MAC headers and cats, slp loud mouth cat back exhaust, msd superconductors, slp lid intake, ls6 MAF, Hypertech Programmer III, and a Hypertech Powerstat 160 degree. My car was eating excessive oil, more than a quart every 1,000 miles. GM ran a oil consumption test on my car and decided to rering the cylinders. I kept having black smoke sometimes when I started it cold and when revving over 3,000 rpms. It turned out that I had scratches on the cylinder walls allowing oil to seep past the rings. GM completely replaced my engine with a brand new 2004 crate ls1 motor.

JNorris

iTrader: (4)

Thanks for the suggestion.

Although I have not checked the plugs exactly as you described, I have pulled the plugs and they are consistent (light/white ceramic and electrode) with what you would excect with proper AFR.