Smoke Problem- - - - - - Why?
Smoke Problem- - - - - - Why? I have been really looking into a header and cam install but I have a few friends that have already started their installs and with just a header and orp install both of their cars started smoking terribly. I could understand a little black smoke at wide open throttle but this is White smoke at deceleration. I know of this on 3 cars that had no oil comsuption problems(approx. 1/2 qt. between changes) before;but, now have terrible smoking issues. Whats the problem? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
Re: Smoke Problem- - - - - - Why? I just can not understand why all 3 cars did the same thing after installing the headers and orp. If they were going to smoke this bad with headers, they should have been smoking with the stock manifolds. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
Trending Topics
TECH Regular
Joined: Mar 2002
Posts: 433
Likes: 0
Re: Smoke Problem- - - - - - Why? Was there any tuning ? If they ran them pig rich over extended periods it could be possible piston rings took damage from flushing oil film out of the cylinder walls.
<small>[ October 17, 2002, 05:35 PM: Message edited by: pekkaz ]</small>
<small>[ October 17, 2002, 05:35 PM: Message edited by: pekkaz ]</small>
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Re: Smoke Problem- - - - - - Why? I know that one of the cars has a Maf translator and another one has had no tuning at this time. According to autotap, The cars are running real close on their air fuel mixture. I could understand cylinder wash but these cars started smoking from the time we backed them out of the garage. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
TECH Regular
Joined: Mar 2002
Posts: 433
Likes: 0
Re: Smoke Problem- - - - - - Why? I've also been looking into header/ory install and these kind of issues are really scary. And this is definately not the first time I see the issue raised up. This should be solved.
I've been thinking about it for some time and I'm suspecting headers affect the o2 sensor outputs in a way that PCM thinks it's lean when it's not. Then either people tune LTRIMs to 0 or PCM raises LTRIMs to cure the lean condition PCM thinks it sees but in reality as a result part throttle will be rich. Getting LTRIMs to 0 will put WOT about in line though by preventing extra fuel to be added for WOT.
Has anybody verified their part throttle a/f in wideband with LTRIMS close to zero ?
I've been thinking about it for some time and I'm suspecting headers affect the o2 sensor outputs in a way that PCM thinks it's lean when it's not. Then either people tune LTRIMs to 0 or PCM raises LTRIMs to cure the lean condition PCM thinks it sees but in reality as a result part throttle will be rich. Getting LTRIMs to 0 will put WOT about in line though by preventing extra fuel to be added for WOT.
Has anybody verified their part throttle a/f in wideband with LTRIMS close to zero ?
On The Tree
Joined: Aug 2002
Posts: 162
Likes: 0
From: Knoxville TN
Re: Smoke Problem- - - - - - Why? thanks gm racin for this post. i'm one the cars he is talking about. normal driving there is no smoke. but when youlay into it and let off on decel it pours out white smoke. any help would great. thank
Re: Smoke Problem- - - - - - Why? You all are telling different stories here.
Black smoke, white smoke, accelerating,
decelerating, etc., etc.
Smoke on deceleration 1s most likely the
PCV. Super-high engine vacuum, with the
PCV purge supply fed from behind the throttle
plate, just wants to slurp up oil. But this
should really be bluish-gray smoke, not white.
I've seen white on other cars with loose
intake bolts, but those were "wet" intakes.
There should be no way of sucking in water,
except for a bad head gasket, on the LS-1.
Black smoke under load is most likely mixture.
You can get visible particulates from either
gross rich or gross lean, all you need is to
misfire. You would know which, by whether or
not you have knock / knock retard. You could
instrument up the O2 sensors and look at real
time voltage under the conditions of smoke.
Headers change tuning. Always have. Only on
these cars it costs you $595.00 to rejet
your carb. Some people get by with tricking
sensors on the cheap, but it takes a computer
to properly adjust a computer upside the head.
Black smoke, white smoke, accelerating,
decelerating, etc., etc.
Smoke on deceleration 1s most likely the
PCV. Super-high engine vacuum, with the
PCV purge supply fed from behind the throttle
plate, just wants to slurp up oil. But this
should really be bluish-gray smoke, not white.
I've seen white on other cars with loose
intake bolts, but those were "wet" intakes.
There should be no way of sucking in water,
except for a bad head gasket, on the LS-1.
Black smoke under load is most likely mixture.
You can get visible particulates from either
gross rich or gross lean, all you need is to
misfire. You would know which, by whether or
not you have knock / knock retard. You could
instrument up the O2 sensors and look at real
time voltage under the conditions of smoke.
Headers change tuning. Always have. Only on
these cars it costs you $595.00 to rejet
your carb. Some people get by with tricking
sensors on the cheap, but it takes a computer
to properly adjust a computer upside the head.
Re: Smoke Problem- - - - - - Why? I have been talking about white smoke all along! Not black smoke. The pcv is not the problem either, As we have bypassed that. Thanks guys for the input. Any more ideas we might try.
Re: Smoke Problem- - - - - - Why? I am in the same boat. Headers, custom exhaust, Delete EGR, AIR, Watching A/F mixture all of the time and running fine on that but get white/gray smoke upon deceleration when I put my foot throught the floorboard. PCV is going to the catchcan and collecting oil about 1/4 quart every two weeks but I am using about a quart every two weeks. Anybody got any ideas?
TECH Regular
Joined: Mar 2002
Posts: 433
Likes: 0
Re: Smoke Problem- - - - - - Why? If my theory, which is mostly based on suspicion, is right then with headers your piston rings gradually get damaged because of continuously running rich at part throttle. Your computer thinks the a/f is fine and if you look LTFTs everything seems ok too. If header install affects o2 sensor readings in a way that PCM thinks the a/f is lean when it's not this can happen and editing pcm tables probably won't help or , well, at least the methods I've seen documented.
Do you guys recall how headers affect a/f in a carbureted car ?
Do you guys recall how headers affect a/f in a carbureted car ?
