Won't run without choke (solved)
 

I just picked up a 1931 sedan Saturday. The carburetor was pouring gas from what seemed every seal. I just rebuilt the carb and no leaks. However the car will not run unless I keep the choke pulled slightly. Only thing odd on the rebuild was I had to use to washers under the float to get it to it's 5/8 settings. The car had been sitting for over a year. Any help would be greatly appreciated.https://uploads.tapatalk-cdn.com/201...a7b37c9aa8.jpghttps://uploads.tapatalk-cdn.com/201...031f0ec805.jpg

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Re: Won't run without choke
 

Where are running your gas adjusting valve? It should be about 1/2-3/4 open to start, and about 1/4 open to run when warmed up. The filter on the side of the carb should also be more vertical, but that shouldn’t affect performance.

Re: Won't run without choke
 

You beat me to it. I was just writing the same thing.

Re: Won't run without choke
 

When you say 3/4 do you mean 3/4 of a turn? Just tried with no luck. Here is a link to the video I just made of me working the choke. You can hear the engine inacordance with the choke. I couldn't figure out how to post the video on here so here is the video on YouTube. https://youtu.be/EvcFTxcw10c. Not sure if this helps.

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Re: Won't run without choke
 

I turn ours one complete turn to the left when starting car cold. Once car starts, I turn back to the right to half turn open until car warms up. Than close a little more depending on how car is operating.

Remember when you close valve, (turning to the right) do not tighten down hard. Just lightly close valve, turning to the right. I close valve every time we shut car off.

Re: Won't run without choke
 

The video really helps. It sounds like you have a very lean mixture. Partial choke is richening it up.

For the GAV, you gently close it and note where the little indicator is pointing on the knob face. From there, open 1/2 turn to 3/4 turn back open (CCW) for a rich starting mixture. As it warms up, you can slowly close it (lean it out). If you go too far, the engine will stumble; just open it back up a touch from there.

How fresh is the gas? People argue with me about this all the time, but I have seen many a Model A and Model T not want to run on old gas. Put in fresh gas and it runs great.

After that, you have 2 options to investigate that could be giving you a very lean mixture:

1) A clogged jet or passage in the carb that you just rebuilt, not allowing enough fuel in to keep it running. This can often be compensated for by opening the GAV. (Not a permanent fix, but to diagnose it.) Try blowing backwards through al of the jets with carb cleaner spray, see if any trash comes out. Make sure the spray actually makes it out the other end of the passage.

2) A massive vacuum leak at the intake manifold that is letting too much air into the engine that the carb does not know about, is not putting any fuel into. Look at where manifold bolts to engine. Nuts tight? Gasket good? Look for a cracked manifold. Check where carb bolts to manifold.

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Re: Won't run without choke
 

I cant tell but is there a gasket between the carb and intake? If not that could be a source. If your unsure get the engine running in any fashion then spray carb cleaner around all these joints to eliminate vacuum leaks. Also be aware the wiper fitting and vacuum wiper itself if equipped.

Re: Won't run without choke
 

There is a gasket between carb and intake. No noticeable cracks. There is a 50/50 mix of new and old gas. Also I checked the wipers as someone suggested. Yup the hose was split. I put a screw in the hose and now it will idle. But if I try to give it gas it does. Also the motor sounds like it has a bad knock.
https://youtu.be/r16d8TkNh1k

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Re: Won't run without choke
 

I watched the second video. You have proven that the GAV works because the engine died when you closed it completely and tried to run the RPM up. Leave it open 1/2 turn to 1/4 turn.

Have you checked the point gap and the initial timing? It now sounds like the timing is off. Once the engine starts, move the spark lever on the left 1/2 way down for idle. Always up to start.

Re: Won't run without choke
 

When you get it running right, take a 24’’ dowel or a long screwdriver or an engine stethoscope and see if you can locate the approx center of that knock.

Re: Won't run without choke
 

Everyone please know I appreciate you all taking the time to help. I work 2nd shift so the battle had to end for the day. However I did notice that the car will start with the timing lever in any position. Not sure if this is normal. There is a Model A cruise tomorrow I plan to visit just to see the cars and get some advice. When I get back from the cruise I will start back on the car. I will check the timing and go from there. Again I appreciate the help and any further help.

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Re: Won't run without choke
 

While you are attending the cruise, see if someone there lives near you. Perhaps they might be able to come over and give you a hand with it.

Re: Won't run without choke
 

Marco has good timing instructions on his site. http://www.abarnyard.com/workshop/timing.htm

Bob

Re: Won't run without choke
 

Please buy and read a couple books on the operation and peculiarities of the Model A before you go any further. At least a get reprint of the original owner’s instruction manual so you get an introduction to how the car should start and run. You will avoid a lot of trouble and headache with just this one simple book. $17 from any Model A parts supplier. You can get one specifically for the late 31 with your type of carburetor.

Also, while your Model A will start with the spark lever in any position, to avoid damaging your Bendix you must start it with the lever all the way to the top. As soon as it fires, pull it down to about 9:00. Driving it too far advanced or retarded will damage your engine and cause overheating. There is much more to the proper operation of Model A, but the Owner’s Instruction Manual will get you started in the right direction.

I am assuming your car is set up in a stock manner and all the necessary parts are properly installed and operational.

Finally, join a local club if you can.

Re: Won't run without choke
 

If the passage from the secondary well is plugged it will do the same thing. First time I found this was rebuilding a side bowl carb like this one. This will plug the cap jet. I have heard timing gears make this kind of noise as well. It would be worth it to pull the side timing gear cover and inspect it. Marco's timing diagram is dead on and will take care of your timing. If you have original points once the rubbing block starts wearing it will quickly close the point gap and add to your troubles.

When it comes to carb problems take a few minutes and review the operation of the zenith carb from this excellent site. www.modelabasics.com. Great animations that really show you whats going on.

Re: Won't run without choke
 

Have a look around your workbench - there may be a venturi hiding there!

Re: Won't run without choke
 

Oh my gosh!!!!!! That's it!!!!! I forgot to put it back in!!! I'm such an idiot. I'll get it in and update everyone. Thanks Synchro909!

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Re: Won't run without choke
 

I flatly refuse to say how I knew that!!:rolleyes:

Re: Won't run without choke
 

You get a gold star, Synchro :)

Re: Won't run without choke
 

The car was been sitting for "over a year" as can be read.
Last week I started a Willys Jeep that has been stored for more than 16 years ; it started within 2 minutes on the old gas. I also started a few motorcycles a couple of months ago that were sitting 4-5 years, and again no problem with the gas here.