Black flagged!
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Black flagged!
Hoping to get some advice on the direction to go. I was black flagged on our first time trials day for too much smoke. It's an LS1 so oil needs to be managed, of course. I have valve cover and pcv vents going through a catch can, so there can't be too much oil getting in through the air.
I did have a tune this year so thinking it might be too rich. All the plugs came out looking black and juicy. I'm spraying black soot out the exhaust on revs and start up, doesn't feel like oil.
Anything else to check before I go back to the tuner complaining?
Jim
I did have a tune this year so thinking it might be too rich. All the plugs came out looking black and juicy. I'm spraying black soot out the exhaust on revs and start up, doesn't feel like oil.
Anything else to check before I go back to the tuner complaining?
Jim
Le Mans Master
Joined: Aug 2005
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From: CA.
St. Jude Donor '13-'14-'15
If the smoke is white or grayish it is OIL--Then i would suspect you don't have your PCV system plumbed correctly--The crankcase is not vented correctly nor if you are using a PCV valve it is again NOT in the correct location If you choose to vent the valve covers entirely with breathers to atmosphere and delete the PCV system there will never be any oil injestion into your engine --I do this on many street/race type applications--but realize they won't pass smog that way
It is very rare on any computer controlled engine to become so rich that it puffs black smoke from overrich fueling---If it does this would indicate a huge mechanical malfunction somewhere--Without seeing your tune I would find it very unlikely that any competent tuner would have your tune so far off to puff black smoke
It is very rare on any computer controlled engine to become so rich that it puffs black smoke from overrich fueling---If it does this would indicate a huge mechanical malfunction somewhere--Without seeing your tune I would find it very unlikely that any competent tuner would have your tune so far off to puff black smoke
Drifting
Joined: Apr 2007
Posts: 1,517
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From: Lafayette Louisiana
Hoping to get some advice on the direction to go. I was black flagged on our first time trials day for too much smoke. It's an LS1 so oil needs to be managed, of course. I have valve cover and pcv vents going through a catch can, so there can't be too much oil getting in through the air.
I did have a tune this year so thinking it might be too rich. All the plugs came out looking black and juicy. I'm spraying black soot out the exhaust on revs and start up, doesn't feel like oil.
Anything else to check before I go back to the tuner complaining?
Jim
I did have a tune this year so thinking it might be too rich. All the plugs came out looking black and juicy. I'm spraying black soot out the exhaust on revs and start up, doesn't feel like oil.
Anything else to check before I go back to the tuner complaining?
Jim
I remember the the old days at the strip when didn't matter how much you smoked so long as you got to the white line ahead of the car next to you. And dude with flags started the race Another dude 1/4 away with flag decided who got there first.End of event could do " challenge Racing" ... $$, $$$ ,$$$$ or title. Drag racing use to be fun.
Last edited by UM Rebel; May 13, 2018 at 02:56 AM.
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Thanks tblu92, the smoke was described as black, it worried the track so much that they scrambled rescue to the hot pit to escort me to the garage. The venting seems correct, I'm burning less oil than I was at prior events, and the catch can seems to be catching. All the plugs are wet and black, that's what keeps me from thinking it's a valve seal. I'll see what the tuner has to say tomorrow.
Le Mans Master
Joined: Aug 2005
Posts: 5,375
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From: CA.
St. Jude Donor '13-'14-'15
Black smoke is mostly always excessive fuel or not enough airflow
If this just started happening these are the most common issues
1. Fouled or dirty MAF dues to over oiling of a cold air intake that is oiled--Clean the MAF with brake clean
2. Front 02 sensors that have failed ( especially if you have LT headers)
3. Fuel pump regulator failed ( check fuel pressure at idle it should be about 50-58 PSI)
4. Dirty air filter---
5. Bad MAP sensor--
6. Bad fuel pump
If this just started happening these are the most common issues
1. Fouled or dirty MAF dues to over oiling of a cold air intake that is oiled--Clean the MAF with brake clean
2. Front 02 sensors that have failed ( especially if you have LT headers)
3. Fuel pump regulator failed ( check fuel pressure at idle it should be about 50-58 PSI)
4. Dirty air filter---
5. Bad MAP sensor--
6. Bad fuel pump
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Thanks for the additional info, all good things to check. I may have narrowed this down a bit but can't seem to solve it. I'm getting a P0113 code for the IAT sensor. I clear it but it keeps reappearing, even after replacing the sensor. I did not know that an open IAT circuit would cause a rich AFR, but apparently it can.
So apart from tearing apart the harness, how do I troubleshoot this? Is it possible this could be caused by another sensor down the line like O2? I'll get it on the lift tomorrow and check that wiring.
So apart from tearing apart the harness, how do I troubleshoot this? Is it possible this could be caused by another sensor down the line like O2? I'll get it on the lift tomorrow and check that wiring.
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Burning Brakes
Joined: Jul 2009
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From: smyrna de
Willing to bet your catch can is filling up with oil due to the high vacuum levels achieved on the track. Can fills up with oil, then starts getting sucked into the intake manifold. Happened to me before. For track days I vent the can to atmosphere and it only collects a tiny amount of oil all day vs filling the catch can in about 2 sessions when attached to the pvc/vacuum. The high rpms while throttle is closed during braking causes the really high vacuum levels. If u got blacked flaged because it was that over fueling/ rich. You would have most likely noticed it running very poorly at wot.
Last edited by MX621; May 17, 2018 at 09:28 PM.
Burning Brakes
Joined: Jul 2009
Posts: 976
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From: smyrna de
Valley cover vent and drivers side valve cover go to catch can. Top of catch can goes to intake manifold. Pass side valve cover pulls fresh air from behind maf completing the pcv setup for normal street use. Yea I was filling my can about 1/2 way per 20 min session. By 2 sessions it was full and started smoking. First time it happens I thought I hurt the motor. Lol. Now when doing a track day I put my filter on top of the catch can and vent to atmosphere. After 6 20 min sessions it’s prob 1/8 the way full. I’m using a custom modified Moroso/Endyn catch can
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Thanks MX621 - have any pictures of your setup? The filter in particular. The Elite Engineering can is the opposite, top is routed from PCV and lower hose to intake. I know a guy that runs two cans, one for the PCV and one for the valve cover vent.