Black Soot ... ????
Black Soot ... ???? When I let my car sit and idle for just a few minutes, what makes the huge black soot spots on the driveway ... behind the tailpipes? It's moisture mixed with soot. Could this be engine problems or does normal overnight condensation just simply flow out the exhaust and carry the soot out with it? It leaves a HUGE black spot about 12" wide or more. 
might just be running really rich at idle especially with the cam. moisture is normal especially right after startup but the soot may be from too much fuel. Did you get a street tune or just a WOT dyno tune for the cam?
NLP tuned the car, recently. A/F was right on the money ... went back a couple weeks later (in January of this year) and the A/F was still the good. I dyno'd with my cutout open.
With the Borla restrictive plate now installed in my exhaust, it was pushing all exhaust though the Borla muffler ... that should have made it run more lean ...
With the Borla restrictive plate now installed in my exhaust, it was pushing all exhaust though the Borla muffler ... that should have made it run more lean ...
Last edited by JEB99TA; Apr 17, 2005 at 07:54 AM. Reason: sounded too arrogant > removed some wording
Mine Z28 does the same thing at idle and blows black smoke at WOT only in the warmer months. In the winter it does not blow black smoke at WOT.
My WB shows the AFR to be 14.7:1 at idle and 12.7-12.9:1 at WOT. All I can figure is that the engine is experiencing incomplete combustion. Maybe a timing issue?
John
My WB shows the AFR to be 14.7:1 at idle and 12.7-12.9:1 at WOT. All I can figure is that the engine is experiencing incomplete combustion. Maybe a timing issue?
John
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Verdad Gallardo My rear O2 sensors were turned off, as well. Mine also gives off a black smoke signature at WOT ... as soon as I hit about 5500 rpm's. Maybe I'll try changing out the 02 sensors and see if that fixes the prob. If I hit WOT several times really hard, there's like a mist of oil on the right side of my car ... some sort of blowback or something. Wouold bad O2's cause that, as well? There's no oil on the engine, anywhere. It's like it's being blown out of the crankcase in the form of smoke ... weird stuff.
Originally Posted by JEB99TA
My rear O2 sensors were turned off, as well. Mine also gives off a black smoke signature at WOT ... as soon as I hit about 5500 rpm's. Maybe I'll try changing out the 02 sensors and see if that fixes the prob. If I hit WOT several times really hard, there's like a mist of oil on the right side of my car ... some sort of blowback or something. Wouold bad O2's cause that, as well? There's no oil on the engine, anywhere. It's like it's being blown out of the crankcase in the form of smoke ... weird stuff.
Are you running the stock fuel injectors?
No, upgraded when TSP had the entire rail and injector assy with the 28.8 Bosch injectors on sale for $60.00 ... just couldn't pass that deal up. Duty cycle is below 80% at WOT.
TECH Apprentice
Joined: Jan 2004
Posts: 328
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From: Los Angeles, CA
Catch can may help, others on here have said that it helps with the soot/smoke. I've only had mine for 500 miles, but I've caught about 3 ounces of smelly oil that would have ended up in my intake manny.