Looking for advice for my carb issue. It's an AFB Carter and it isn't spraying fuel into the bowl as it should, so the car won't start. I don't want to keep manually adding fuel each time I want to start it. It also has been rebuilt and adjusted if that makes a difference at all. My other buddy can't even figure it out.
Are you saying the acceleratior pump is not working? If so, check linkage, pump, check valve, and see if the spray nozzles are clear. It’s been forty years since I worked on an AFB, so can’t give you any peticulars. Just the basic. Bones
It shouldn't...be spraying fuel into the "bowl" That should already have fuel in it..! It should be spraying fuel into the venturi/booster area. 1. No gas in the carburetor. 2. Accelerator linkage not connected. 3. Throttle not connected. 4. The spring and lock on the pump shaft (above the diaphragm) are not in place. 5. No ones pushing on the gas pedal. 6. The steel ball is not at the bottom of pump well. 7. The steel ball is not in the squirter well location. 8. The squirter is not in place. Bought all I can think of at this hour. Mike
It probably is a political problem, not a carburetor problem! Check this link: http://www.thecarburetorshop.com/Troubleshooting.htm#Hardstartcold Jon.
If you have to put gas down the ventures, then for some reason the accelerator pump isn't working. There are only two possibilities for that, the rubber seal on the pump has gotten hard or the passages to the nozzles or the nozzle itself are plugged
I think what carbking mean's is that you have to see if there is any fuel in the carb. After you prime it and let it run, shut it off and see if any fuel comes out of the shooter when you pump the throttle, if no, accel pump, if yes, fuel is evaporating when the engine is shut down for awhile. ( Ethanol blend's )
From the troubleshooting page I posted above: Accelerator pumps Often the accelerator pump gets the blame for other problems. It is very easy to test the function of the accelerator pump. Start the engine, and warm to normal operating temperature. Shut off the engine. Remove the air cleaner. The choke butterfly should be fully open, as the engine is warm. Observe the pump jet in the carburetor, and with your hand, work the carburetor throttle to the wide-open position. You should observe a healthy squirt of fuel from the pump jet. A single barrel carburetor will normally squirt a single stream; while a two or four barrel carburetor will normally squirt 2 streams. If you see the stream(s) of fuel, the pump is working. It is important to start the engine prior to doing this test. With modern gasoline, it is quite possible the carburetor will be completely dry prior to starting. If there is no gasoline in the bowl, the pump will not work; and this would give a false result. Jon
Could the float level be so low that all of the fuel evaporates when the engine is shut off? If so, that would explain why it may have a good pump shot while running, and none when trying to start it after it has cooled down (and the fuel has evaporated). I have also had weak fuel pumps on quadrajet equipped small block chevys do the "needs primed to start after sitting" deal on me.
It actually worked fine after the rebuild for quite some time. Even drove around the country side without issue & ran strong. Sent from my iPhone using The H.A.M.B. mobile app
The accelerator pump shaft on those are plastic.As they get older they develop a curve.This curve causes it to not travel correctly.Disconnect its linkage,and the shaft may lean to one side.It shouldnt.
If I remember correctly , and this maybe on the timeout bench now for me . The pump on an AFB was leather , if a rebuild it maybe gone by now anyway . If it is still a leather pump and it drys out it usually takes a bit for it to gas soak and swell up to work properly again after a timeout also . Any help here on this memory issue ?
That sounds kind of familiar to me too. And it seems like at least some of the carbs with the leather pump seal also had a small garter spring inside them that helped load the seal against the inside of the accelerator pump well. Don't remember ever seeing one come out of place but there's always a first time for everything.
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