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I promise I did a search, and didnt find what I was looking for.

Ok heres the deal. I notice we have coverted the exhaust tip getting black real quick and its all probably related. But still curious. Well, I noticed sometimes on a little spirited throttling, I notice a good puff of smoke out the back. Is this normal on a turbo or should there be something to be concerned about. I'm at about 2k miles.
 

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Under high loads, the engine will run rich resulting in some black smoke (unburned hydrocarbons).

It doesn't really have anything to do with the turbo per se but the MS3 runs richer than most cars under hard acceleration.
 

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going from full load to full throtle lift will almost always produce a bit of unburnt fuel in the exhaust gas. Not much you can do about it, even with tuning this will still happen to a certain degree.
 

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black is normal, but not ideal...blue is bad and so is lots of white
 

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When I was first investigating the MS3 at the local dealer, I had them start one so that I could hear it run. It was about 18deg F at the time and even on start up, it blew a few puffs of obviously rich black smoke. I attributed it to the cold start enrichment which seems, umm, aggressive.
 

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black is unburnt fuel, blue is oil (bad), and tons of white is coolant (bad)
 

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Man last night you woulda thought i was driving a diesel. I was being a stoplight warrior shifted to second and saw a huge puff of black stuff, i sure would hate to be the car behind me. Maybe that why im getting 18 mpg, all my fuel is flying out the tailpipe lol.
 

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I don't really think that our cars in general run any richer than any other newer cars given the strict emission standards they are forced to meet (Tier II, Bin 5 on my non-California MS3, I am not sure if the CA cars have to meet a stricter standard or not). Gasoline cars almost always bounce around a lambda value of 1 after the catalyst reaches operating temperature. But because of direct-injection, our cars are predisposed under certain conditions (typically cold starts and heavy accelerations, where the engine may not be in a closed-loop fueling mode) to form particulate matter, just like a diesel engine does. There have been a lot of studies on this subject by the EPA, CARB, OEMs, the EU agencies, every catalyst and particulate filter manufacturer, etc.

These same conditions in a non-DI engine will also put that car into similar fuel-enrichment strategies that the MS3 uses, but they don't form particulate matter like a DI or CI engine will.
 

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I don't know what exactly is going on but I never had this much black build up happen this quick on the tailpipe of my Subaru WRX. For some reason the tailpipe on the MazdaSpeed 3 gets black after 1 trip.

It makes me think the engine is running too rich and I make that assumption from experience I had on the WRX. When I put an after market BOV on the WRX it put all of the extra blow off from the intercooler out into the atmosphere. THe stock BOV directed blow off back into the intake. So the aftermarket one let that air go and the computer never realized that the air was being lost and it thought the ari was being reused for combustion. Because of that the engine woudl run rich and I actually got a CEL a few tiems because of it.

At the same time I noticed unburned fuel and black build up coming out the tail pipe. IT is similary to waht I see on the Mazda but not exactly the same. It jsut seems liek the Mazda is running slightly rich. Probably does nto cause problems but I would think a car like this would be a bit more lenaned out.
 

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this for the none turbo 3 manual

Blue smoke (Burning oil):
• PCV valve malfunction
• Engine internal oil leakage

White smoke (Water in combustion):
• Cooling system malfunction (coolant loss)
• Engine internal coolant leakage

Black smoke (Rich fuel mixture):
• Air cleaner restriction
• Intake-air system is collapsed or restricted.
• Fuel return line is restricted.
• Excessive fuel pressure
• Improper engine compression
• Injector fuel leakage
• Ignition system malfunction
 

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well, I had seen the PUFF before, but it was either at night or low visibility. hard to tell what was really going on, specially with the tint a the back.
but today, bright and sunny and I saw the PUFF after shift from second to third at 6000 rpms.
It was black and was more like "here - eat my dust - pooof" to the SUV behind me before I took off.

By the way, only see it when I PUNCH it! make me want to say its right during the turbo lag...I think just before the turbo KICKS in.
but not sure.
 
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