1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Puff of smoke every cold start.

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Old Oct 21, 2020 | 03:30 AM
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Puff of smoke every cold start.

So every time I start my car up I get a second worth of Grey ( NOT Blue ) cloud of smoke. It's quite literally one large puff that dissipates within 5 seconds. The issue only happens during cold starts or when the engine floods ( in that case its a 3-second puff with a lot more power, nothing like I had when it was leaking coolant, that was a smokescreen)
My engine has roughly 400 miles on it, there appear to be NO signs of water consumption, I have checked.
My mechanic said it was normal due to the premix I was running ( lucas synthetic two stroke, I'm now running idemitsu but it smells like **** so I'm switching back to lucas) BUT said it would go away after 200 miles and the subsequent reduction of the amount of premix he told me to use .
My car has NO SMOG EQUIPMENT, it's ridding dirty.
Is this normal or is it a symptom of my carburetor which floods or something else? ( and subsequently evaporates, and i assume a small amount seeps into the engine) . Also my engine has healthy compression after the rebuild.

Last edited by Frogman; Oct 21, 2020 at 03:39 AM.
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Old Oct 21, 2020 | 06:19 AM
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Honestly, it seems normal to me. If it goes right away, I honestly wouldn't be worried.
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Old Oct 21, 2020 | 09:06 AM
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a puff of smoke is totally normal.
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Old Oct 21, 2020 | 10:31 AM
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Mine does the same thing, sometimes it’s grey sometimes it’s more blue, usually goes away immediately
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Old Oct 21, 2020 | 03:24 PM
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So no fix for this? Its annoying stinking up my driveway every morning
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Old Oct 21, 2020 | 04:01 PM
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welcome to the World of Oil Burning Rotaries. My 110k mile 80 SA has done this the 20 yrs I have owned it. Orig engine, burning a minimum of (oil-stick-checked) oil. Could something be done for minor improvements? Probably. Would it be worth it? unlikely...
apologies to the neighbors!

Stu A
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AZ
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Old Oct 21, 2020 | 09:32 PM
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Just making sure it's not an actual issue. the oly problem my car has ATM is the carb and a minor trans leak at the speedo gear .
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Old Oct 23, 2020 | 11:02 AM
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Do you not have the OMP? Maybe the premix is not right?

I don't premix, 60k on the clock and not any noticeable smoke on startup. Rich fuel smell is another story.
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Old Oct 23, 2020 | 12:26 PM
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Neighbors love rotary engines.
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Old Oct 23, 2020 | 09:38 PM
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Originally Posted by Ckforker
Do you not have the OMP? Maybe the premix is not right?

I don't premix, 60k on the clock and not any noticeable smoke on startup. Rich fuel smell is another story.
I have no idea if i have my OMP anymore.. I was told to premix by the guy who built my engine.
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Old Oct 24, 2020 | 06:43 PM
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If you are not burning coolant, then it sounds like moisture in the air and it is normal. I rarely start the car is if is below 45 or 50 but the other day we had to get it inspected and it was in the 30s out. There was a lot more white smoke but it quickly went away. It is not there when it is warm outside.
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Old Oct 24, 2020 | 08:31 PM
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The persistent "steam" coming out of exhaust pipes in the winter is just that. H2O is a constituent of normal exhaust gas. You see it more in cold weather as it condenses quickly when hitting the cold air (same reason cooling towers, for example, are so obvious is winter compared to summer).

Oil burning generally has a blue tinge, and coolant burning is white and more copious than the normal level of H2O in the exhaust.
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Old Oct 24, 2020 | 10:33 PM
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Neighbors not getting rotary engines...

Last night I got home from an errand and backed the 84SE into the driveway and then pushed it the rest of the way into the garage, nose out. A neighbor of mine was walking past the front as I was closing the coach gates and he said, "She's running a little rich." I replied that it always runs a little rich, and thats just unburned hydrocarbons. "Smells great", he said.

I don't know if he was being sarcastic or not.
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Old Oct 25, 2020 | 11:47 PM
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From: Downey California
today it was cold outside ( low 50's) and I got a constant stream for about 30 seconds. I capped a hole that comes out of the pipe where you add oil. , the mechanic said it's a breather hole but I'm concerned humidity or other gunk will get in there so I put a rubber cap on it with a tiny pin-sized hole, I honestly felt the car idled better and vibrated less, no idea if its a placebo or if the little hole contributes to something. Checked coolant levels again today, the cap was full. Must be a combination of running too rich and humidity then.
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Old Oct 27, 2020 | 07:24 PM
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My SE doesn't have cats so it is not fun being around it. Nobody follows me closely for long so it has to be bad but I don't smell anything until I stop.

t sounds like the hole is a vacuum leak.
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Old Oct 28, 2020 | 01:40 PM
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From: Downey California
Originally Posted by TimNH
My SE doesn't have cats so it is not fun being around it. Nobody follows me closely for long so it has to be bad but I don't smell anything until I stop.

t sounds like the hole is a vacuum leak.
i don't have smog or an air pump any more , what vacuum leaks ?
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Old Oct 29, 2020 | 06:49 AM
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I think its just fine and wouldn't worry about the exhaust smoke. Good idea on capping the breather and adding a pin hole. My son asked about the smoke coming from my RX-8 the other day when I started it. It was completely normal and I explained to him how the engine is rich on first start and that its cold outside and that you will see more exhaust traces when its cold out.
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Old Oct 29, 2020 | 03:01 PM
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Originally Posted by Frogman
i don't have smog or an air pump any more , what vacuum leaks ?
That port is usually connected to the purge valve which is closed unless the throttle is wide open. I was thinking of something else and when you plug a hole and the idle improves it can be a vacuum leak. I stand corrected.
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Old Jan 14, 2021 | 01:28 PM
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Update, the issue went away almost entirely after adjusting the air mixture screw on the carb, it now just vents a dispersed cloud even if the car floods. So I can confirm it was the carb running wayyyyy too rich.. funny enough the smoke wasn't black .
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