1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks Discuss the Early Eighties Bullnose Ford Truck

Auto Choke

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Old 09-10-2011, 07:28 PM
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Auto Choke

On a 1983 f-150 with auto choke, am I suppose to push the gas pedal before I start the truck? I've tried, but still have to start it a couple of times to get it running.
 
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Old 09-10-2011, 07:46 PM
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Yes, push it before you try to start it. You need to experiment to see what your truck likes as far as starting routine. When you push the pedal to the floor and then let up, you are doing two things;
1. You are squirting fuel into the engine.

2. You are relieving the pressure between the throttle and the choke mechanism, so the choke can freely shut and the fast idle cam can set.

You may find your truck starts better if you push the pedal twice before starting, or possible once in the summer, and twice in the winter. The first time will set the choke and give a squirt of fuel and the second time will give another squirt of fuel.
 
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Old 09-10-2011, 08:03 PM
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Dave's right with everything he said. But, it is possible that your choke isn't adjusted properly if you have to start it a couple of times on a cold start. The fact that it starts probably means your accelerator pump is working and giving the squirt of fuel Dave mentioned. However, if the choke is set too lean then it won't close firmly enough to keep the engine running after it uses up the squirt of gas.

If you decide that it isn't working well enough then we can talk you through making a small change to the choke - after writing down where it is now so you can get back there if need be. Just let us know.
 
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Old 09-11-2011, 08:34 AM
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Thank you. I'll take your advise and let you know how it goes.
 
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Old 09-11-2011, 01:06 PM
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A 1983 Ford truck would have come with a hot air (thermostatic) choke and an electric assist. The "hot air" is the primary choke and it would have an insulated tube connected from the choke cap to the passenger's side exhaust manifold. This tube typically rusts off, so check to make sure it is still there. If it is not hooked up, your choke will never work as it should. The "electric assist" is secondary and not absolutely necessary but it should have a wire connecting the choke cap to the back of the alternator.

Watch this video a fellow member made over in the 1973 - 1979 forum demonstrating how a carbureted vehicle should start:

https://www.ford-trucks.com/forums/10...art-video.html

As you can see, a carbureted vehicle can start in any weather and run just as good as any modern fuel injected engine, so long as everything is adjusted correctly. That means a properly set choke is absolutely necessary for cold starts and overall driveability!

Since this is your first carbureted vehicle, you need to understand that it is a bit different than modern EFI vehicles in that now you have a choke and a manual fuel pump to deal with. You will have two starting procedures:

1. If you drive your vehicle daily, one or two pumps of the gas before starting should be all it takes. As long as the choke is hooked up and set correctly, your truck should start right up, even if the temperature is 0 degrees. It got down to near zero degrees in South Carolina last winter, and my own 1985 F150 started right up and continued running without stalling, with only two pumps of gas before starting it. In the summer, one single pump will start the engine every time.

2. If your vehicle sits for an extended period of time, say, over a week or two, the fuel in the fuel bowls in the carburetor will dry up. When this happens, you will need to crank the engine for about 10 seconds (without pumping the gas) and then stop cranking the engine and pump the gas 7-10 times. Your truck should start right up after that.

After your vehicle has been started for the day, you don't need to push the gas down before every start. As long as it is not extremely cold outside, it should start right up. For example, if you stop to get groceries, etc., just get in and turn the key. If it has been say, 5 -6 hours since it was last started, you may need to push the gas pedal down half-way before starting the vehicle.
 
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Old 09-11-2011, 01:18 PM
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Lariat - Did it really get down close to zero there a month ago. It did here as well - our new reality was that 80 was the new zero. Anyway, good information. I forget that not everyone grew up with carbs and chokes.
 
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Old 09-11-2011, 01:34 PM
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Originally Posted by Gary Lewis
Lariat - Did it really get down close to zero there a month ago. It did here as well - our new reality was that 80 was the new zero. Anyway, good information. I forget that not everyone grew up with carbs and chokes.
Good eye, Gary! No, it was over 100 degrees here in South Carolina a month ago, so that was definitely an error on my part. I just changed my original post. It got near zero degrees last winter though, and I really thought my truck would not start up as well as it did. This is my first and only carbureted vehicle as well, and all I used to ever hear about is how difficult carbureted vehicles are to start in cold weather. With my hot air choke set correctly and thermostatic air cleaner in place, cold starts are not a problem at all for my truck.
 
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Old 09-11-2011, 03:03 PM
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I hope he gets a routine down that works for him without messing with the choke adjustments. The choke system can be very complex to a newbie and can take several mornings to get all the adjustments just right.
 
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