Are Chokes Necessary????

[55 Fargo]

Hi all, after the choke wire burned up on my engine tonight, I have pondered what might have been the cause.

It is the OEM wire, it was burned from the terminal ring that attaches to the choke up about 6 inches of wire.

Now what might have caused this, would it have been the wire shorting to the engine block, or was the choking getting too much juice or what.

I am wondering if I run a new wire will this happen again. Should I run a new choke wire and see what happens?

Do I really need a choke, if I am starting my car in temps above 30 fahrenheit.

As I plan to have dual carbs someday, I would not run a choke anyway, so will I need one with a single carb,. I am not being lazy or cheap, I can run a new wire, I just don't want another to burn up all of a sudden...............Thanx Fred

[Normspeed]

Fred, maybe you could put a fuse in the new wire, maybe a 30 amp or so. It sounds like an internal short in the choke to me. I may have a used Sisson choke if you need one. I don't run any chokes on my 53 and have no cold starting problems at all. I do have an electric fuel pump though, and I just pump the pedal once or twice and she starts right up. I warm it up for a few minutes before driving. I like sitting in the driveway listening to the motor run anyway.

[55 Fargo]

Here is a pic of the burnt choke wire.....Fred

[Rodney Bullock]

Fred, with a sigle carb or duals you are going to need a choke. You must have a electric choke, I know this must be very nice however have you ever considered a pull choke? I know I have a older car (1940) and both my thottle cable and my choke cable are used to start my car. I would not be able to start my car without running my battery down in the winter without these two options.I do have a dual carb truck and I use my choke with that as well. I think with a cable choke you have more control of the system. As the car warms I push the choke in until it's ready to drive.

[55 Fargo]

The wire was burnt on the bottom side , it was on the engine block and mighty close to the manifolds, a lot of heat wonder if the old wire burnt a bit, allowing an exposed wire to short, that would create resistance while cranking, this wire is about 14 gauge, but is double insulated, except the 6 inch portion of where it burnt, that extra insulation was worn away in this area.

I am going to run a new 12 gauge wire, and an inline fuse, but why would this little choke solenoid need a 30 amp fuse, isn't that a little high for this, just wondering, not questiong your wisdom Norm..........Fred

[Norm's Coupe]

Fred,

I don't think you need the fuse. It didn't have one originally, so why put one there now.

As Rodney pointed out you do need a choke in our climate. Maybe Normspeed gets away without one due to warmer climate. That car won't start in our climate without some kind of choke, unless its already been running as it was when you run into the problem. When the engine is warmer it doesn't need the choke so much.

That wire probably shorted out for two reasons. First the insulation was burned off in spots and possibly sparked between the block and wire. Also, it's stranded wire. Being as old as it was, some of the strands could have been broken and that could also cause the short. I would simply try a new wire and see what happens. It will probably be ok. I would also try to route the wire so it doesn't contact the block or anything else. You could also put a wire loom on it to help protect it from touching anything hot or sharp.

[Reg Evans]

I had the very same thing happen a few weeks ago on my 49 Suburban with a 59 Truck engine installed. When I got the car the wire had been completely removed so I thought I'd be smart and install a new wire.

Well....the next time I went to start the car that wire turned into a smoke bomb and melted most of the insulation. I figured the choke must have an internal short but haven't looked inside yet.

Normspeed, if Fred doesn't need your sisson choke I'd be interested.

[55 Fargo]

I just started the engine no problem without the choke, it was 32 degree ambient temp, the engine was last started at 9:00 pm last night, the engine started like nothing, it started better than with the choke it seemed. my engine is really for warm weather use, in winter the garage rarely goes below 32.I also have another B&B carb , with manual choke linkage maybe I will go with that.

Reg I will contact Normspeed, about the choke, if I am not interested it's your ball how does that sound, will know today..................Fred

[Reg Evans]

Sounds good to me Fred !

[55 Fargo]

Reg, if I can one up here from other Mopar freaks, I will let you know, will find out today....................Fred

[Norm's Coupe]

Fred,

Could be the car started easy because it 32 degrees and dry in the garage. When it gets colder in there you may have a problem. Also, the choke isn't just for starting the car. It's also to keep the car running smooth while going down the street with a cold engine, especially if you come to a stop.

Now, you could compensate for the choke not working and keep the car from dieing at stops by setting the idle speed up on the accelerator. However, if you do that, it will make the car harder to shift gears and you will get hesitation when you hit the gas fast because it then puts too much fuel in the carb all of a sudden. If you look at the old carbs with automatic chokes, and read how to set the automatic chokes, you will see that the chokes have a step down on them. Thats there so that when the car is cold, it's on the highest setting. As the engine warms up the choke will automatically step the choke down to each other step until it's completely off.

That was for the automatic chokes. Actually, you are supposed to use the manual choke in the same way. Only difference is, you control turning it down by pushing in the choke knob as the car warms up. In warm weather or when the engine is warm, the choke may not come on at all, and of course you may not need to use a manual choke either.

You want some kind of choke on any car to start it and keep it running smooth. Just because you started it once in the garage doesn't mean the car will start all the time or run smooth without a choke.

PS: On later model cars of the late 60's and up the automatic choke is controlled by a "Pull Off Valve", which does the same thing like you manually pushing the choke off slowly.

[55 Fargo]

Thanx Norm, I have manual chokes on my lawn tractor (Honda V-twin 17.5 hp, and my John Deere Snowblower also has a manual choke, I pulll them closed to start, then open them half way once started and run them a bit,then I open them full,I would prefer this type of choke on my flathead. I do have a B&B carb set-up for manual choke. Maybe this one could be used with a universal cable for the choke............Fred

[Reg Evans]

Reg, if I can one up here from other Mopar freaks, I will let you know, will find out today....................Fred

Thanks Fred but I don't quite understand what you are saying here. Maybe I need more coffee.

[oldmopar]

I do not like auto choke always a headache so I convert everything to manual. Its easier, works better and you can get a cable kit in most auto stores that have the cable and necessary adapters to convert. If you have a carb that is set up for manual even better I would rebuild it before install or maybe you could just swap the top of the carbs not sure if it would work but I do not see why not.

Ed

[Normspeed]

A choke does make things easier. But, around the holidays I was in an area where the overnight lows were in the mid to high 20's (F) and each morning I would go out to the frost covered car, pump the pedal, start it up, warm it up for 5 minutes or so, and go driving. No chokes at all in my carbs. That's a dual Ball & Ball setup, not a single. It's good practice to warm your engine up a bit even if you have a choke and a fast idle setup. Good for the motor and good for the soul, listening to it purr.

I'll look in the parts pile this weekend, I'm sure I must have saved at least one Sisson auto choke setup from my old manifolds.

[55 Fargo]

Hi all, closer examination of the choke solenoid wire revealed that it was spliced togther near the terminal that attaches to the choke unit.

It was taped over tightly, I did not notice this before, someone joined to sections of wire, no solder, no butt connector either, it was real loose and frayed. Could this have been the problem.

I have made up a 12 gauge wire with new ends, connected it up, started engine, no problems, the choke is working,will keep an eye on this for any other problems.

I am thinking of putting an in-line fuse on this circuit, can't hurt any, not sure what amperage of fuse is necessary.

I did a contiuity test one lead to the screw on the scissons choke one to ground = conductivity, so the unit inside should not be shorting out,correct?

Thanx all Fred

[blueskies]

I have the chokes disabled on my dual setup. I have found that I don't need them at all, and I live in a cold climate. I'm also running a water heated intake, which helps.

I have driven my car regularly in temps anywhere from -10 degrees and up, and have never had any issue with not having a functioning choke. The engine will not idle right after starting, but if I keep the rpms up just a tad, it is warmed up and ready to go by the time I have backed out of my garage and will idle without increased rpm. By the time I've gotten a block from my house, it's ready to race.

Pete

[Dodgeb4ya]

That choke wire only has voltage in it when the starter cranks-only time it could short out. Two common reasons for the wire to burn are that the wire is old/frayed or not the correct guage and also too long of a screw that tightens the choke wire to the "Sisson" choke unit. Oh, and a high anperage draw because of a shorted choke coil winding. These chokes work very well when adjusted correctly and are electrically ok. I do agree these flatheads will usually run pretty good with out them if started at least once a week and the float bowl stays up on fuel.

Bob

[RobertKB]

I have the automatic choke on my '53 Plymouth and find it works fine and have never had a short on it. I would guess there is an internal problem in the choke itself as they only get power when you turn the key. They also need adjusting and it is very simple to do. I always thought they were hard to adjust but it really is straightforward after an old time mechanic showed me how. Good luck!

[55 Fargo]

There is no internal choke problem, at least that i am aware of, I had to replace a poor wire, it seems to be corrected. The choke itself has contnuity, so it is not shorting internally, to the best of my limited knowledge.

[55 Fargo]

Will continue to monitor the choke, I have made up a new wire, there is continuity, when you place one lead to the screw terminal and one to ground. So I have ascertained it mustbe working.

After a number of starts today, there was no evidence of any more problem, I hope..........Fred ps if this choke is toast, I will need to replace with another

[55 Fargo]

Here is the new wire installed, the engine was started about 10 times so far, no frying yet, should I be okay then.....Fred

[Normspeed]

I used the Sisson choke for quite a while before I went to dual carbs. It's realiable and I agree, easy to adjust. Rugged too. If they had a flaw it would be that they snap shut on every start, cold or hot, and if your engine happens to be flooded with raw gas the last thing you want is more choke.

Reg and Fred, I'll PM you later today. whoever needs it, it's yours for the cost of postage.

[Normspeed]

Thanks Shel! I had heard that the earlier model only uses one mounting stud, is that the case? Mine is off a 53 and uses 2.