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Question about difficult cold start


jps

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I have always had a very difficult time starting my 1929 when the temperature is below about 65 degrees F.  Starting fluid has not helped (when sprayed into the air cleaner just before cranking).  The car has an updraft carburetor.  What suggestions does anyone have to help?  Fuel flow to the carb and spark at the plugs are verified to be OK.  I don't have as much trouble in warmer weather.

 

Thanks

 

John

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When did you buy the gasoline? In some places, the gas they sell in the summer is different than winter gas. I don't know where you live, but it would be harder to start a car in cold weather if the tank is full of summer gas. They add more heptane and hexane in the winter and more octane and nonane in the summer, in places that have cold winters.

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What's the condition of the coil like? 

 

Our 26 was difficult to start until it was replaced with a remanufactured one and now it fires almost instantly in weather around 60f  even without using the choke

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Hi everyone, and thank you for the ideas and questions.

 

My situation is more complex than for what I originally asked, but after about 2 years of working to get the car running again due to several repairs I think that I am back to my original problem that I have always experienced with this car; namely, that I can't get it to start in cool weather (roughly, below 65 degrees).  I have been working through other problems, but I believe the one at present is still the original cold start issue.  Temperatures here are changing a lot each day - I did get it to start on Saturday when the temp was 60+, but then it would not start on Sunday when the temp was only about 45.  Today it only reached 39 but next weekend it should be 55-60 again.

 

The carburetor was rebuilt and adjusted about 3 years ago by Tony Bult.  It is a 1928 Marvel which I prefer over the 1929 version because the '28 still has a brass bowl and I can avoid the pot metal bowl problems of the '29.  I had old gas in the car, about 2 years old with Stabil added, so I siphoned out most of it and filled the carb bowl and fuel pump glass bowl with fresh gas I bought 1 week ago.  In addition, the two aftermarket fuel filters were replaced.  I also had to blow out the low speed jet on Saturday (it was plugged) to get the gas to flow into the carb.  Now gas is definitely getting to it and if I crank too long w/o the engine firing, fuel drips out the air cleaner.  This is traditionally what happens when temp < 65 degrees and I can't get the car to start.

 

Compression is OK on 5 cylinders (55-60 psi) but low on the 6th (40-45 psi).  I have only checked it though when I cannot get the car to start, so these readings are from a cold engine.  I have checked them about 5 times over 7 years and I get the same results each time.  However, I have been able to start and run that way as long as the temperature is warm (ie, summer).  I cleaned up the distributor and bought a new coil last year, along with completely rewiring the car and buying a new battery.  All of those things have helped, but the cool weather starting issue persists.  I always try to start with full choke (unless trying starting fluid sprayed into the air cleaner), medium to high throttle setting, fully retarded timing.  The heat riser was re-sleeved about 5 years ago, and I don't see any leak points for air in the manifold up to the cylinders.

 

I charged the battery about a week ago, but have tried cranking about 25 times since then, so I could put it back on the charger to top off the battery again.  I also can drain the rest of the old gas out.

 

However, I have generally done all of these things (charge the battery, re-time the ignition, re-gap the plugs, etc) several times since I've owned the car and those things help to get he car started when it is warm.  Nothing yet has helped me get it to start when it is cold.  Yesterday after several cranking attempts I took out the spark plugs and only 2 of them had a little liquid fuel on them.  This is how they look each time I have checked plugs after a long period of unsuccessful starting attempts (most or all plugs are dry).

 

My thinking now is that fuel is not making it up to the cylinders, at least not enough fuel to start, because the lower pressure in the venturi causes the corresponding temperature to be even lower than the ambient and the fuel is not vaporizing to mix with the cold air.  Either that or the choke valve isn't cutting off the air enough.  But this must have been a problem even in 1929, so what did people do then to get the car to start in January?

 

John

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One time I tried to start my E-49 when it was cold. It had been 20 overnight and now it was 45 and the air was damp. When I opened the (unheated) garage there was a little condensation on the car because the car was much colder than the dew point of the outdoor air. When I tried to start it the intake manifold became colder due to the evaporating gasoline, and was it covered with condensation. Of course the car didn't start, it was sucking in water from the atmosphere. If the outside of the intake manifold had water droplets on it, so would the inside.

 

Plans are in the works for a heated garage.

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