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black soot or water coming out of exhaust on start up's

Started by Bill Balkie 24172, June 24, 2015, 11:34:51 AM

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Bill Balkie 24172

I have owned a 1957 Seville with a single carb  and never really had a problem with the black soot or water shooting out of the exhaust pipe  always had a little but not much . My convertible has 2 X 4  carb stock with batwing and runs extremely well . Easy starts , decent fuel mileage  8 in the city maybe 13 on the highway . and runs very cool . however the black soot the comes out on start ups is considerable more then the Seville . So much where I find myself cleaning the garage for every time I use it  however I do let the car warm up for a minute nor two before pulling it out .  Is this caused be another problem or is the nature of the beast .

  Thanks,
   Bill
Bill Balkie
1970 Coupe DeVille
2009 CTS

Jon S

If you lightly tap the accelerator 5 seconds after starting the car, the idle should drop down as the fast idle cam drops when the choke opens slightly.  This leans the mixture and should minimize the soot from an overly rich condition of initial startup.  Water normally begins to flow about 45 seconds after startup and is normal.  I get two clear puddles if I leave the car in the garage for over 2 minutes.  If I back it out before that, all is dry in the garage.
Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

Alan Harris CLC#1513

Nature of the beast. We tend to forget now how much cleaner fuel injection is than carbs were.

Condensate and soot are normal on cold starts

Jon S

Quote from: Alan Harris CLC#1513 on June 24, 2015, 06:05:02 PM
Nature of the beast. We tend to forget now how much cleaner fuel injection is than carbs were.

Condensate and soot are normal on cold starts

A properly tuned carburetor is as clean as any fuel injected car. Back in the days of emissions testing, my Corvette registered .0000 and .0001. My mechanic told me the FI cars did not run that clean.
Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

Philippe M. Ruel

Water is due to condensation on exhaust walls after the engine is shut down, and during the time the car is parked.

It may depend on the temperature (more precisely temperature variations) and humidity of the garage, and of the nature and thickness of exhaust system. A thick stainless steel exhaust built for smooth and silent running (many labyrinthic inner walls) can bring out lots of water upon restarting.
1952 60 Special in France.

Roger Zimmermann

The 2 x 4 System is the most stupid thing I have on my cars but that system is good looking. Both the '56 Biarritz and '57 Brougham have a too rich idle; if I try to lean it, the engine is not running correctly. And I have black soot on the RH side as I still have good functionning heat riser.
I don't have those "problems" with my '56 de Ville with its single carb.
Don't forget that one liter (or one gallon) used fuel is giving the same quantity of water at the exhaust. When the engine is warm you don't see it, only cold.
1956 Sedan de Ville (sold)
1956 Eldorado Biarritz
1957 Eldorado Brougham (sold)
1972 Coupe de Ville
2011 DTS
CLCMRC benefactor #101