The Ford Barn

Wayne B · 02-01-2020, 05:23 PM

Hello,
New to the forum. I need a little help. Have a 1950 F3 with a rebuilt flathead, and converted to 12 volts. I can get the motor to start, but fouls the plugs and will not run correctly. Put in a fuel regulator to the carburetor and set it to 2.5 psi. There is no vacuum line now due to the new 12-volt distributor. Does anyone have any ideas?

JSeery · 02-01-2020, 05:39 PM

Welcome to the Barn Wayne. Sounds like a fuel problem, but. What type of distributor? Is it a modern one with a machinal advance or the original style? What are you referring to as a 12 volt distributor, normally a distributor doesn't care what voltage it sees. Is it an electronic distributor?

tubman · 02-01-2020, 05:40 PM

If it has a stock Holley 94 carburetor, I would immediately suspect a leaking power valve. Even if the carburetor has been rebuilt recently, it may be a problem. Currently available Holley power valves (for the 4BBL carbs) look like the older ones and even screw into the carburetor, but they are slightly different and do not seal correctly.

Wayne B · 02-01-2020, 05:48 PM

The distributor in electronic with built in advance. I have the holley 94 carb. Seem like the carb is dumping fuel.

JSeery · 02-01-2020, 05:51 PM

Quote:

Originally Posted by Wayne B

Seem like the carb is dumping fuel.

Sounds like it. Has it been recently rebuilt? There are several members here on the Barn that rebuild them. They can be a bit tricky.

tubman · 02-01-2020, 06:34 PM

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Again, it's probably a leaking power valve. I don't mean to be condescending, but do you know what a power valve in a 94 is, what it's for, and how it works?

Wayne B · 02-01-2020, 06:39 PM

I’ve looked it up and ordered one. Hope this does the trick. Thanks

tubman · 02-01-2020, 06:55 PM

Quote:

Originally Posted by Wayne B

I’ve looked it up and ordered one. Hope this does the trick. Thanks

You may not be out of the woods yet. Not all Holley power valves are created equal, although they look almost identical and screw into the same hole. When Holley went from the 94 series carburetors to the 4BBL's, they changed the shape of the seat slightly and the newer power valves usually do not seat correctly in the older carburetors. They can be made to fit properly with a little lathe work, but not all of us have lathes. If you ordered your power valve from a regular auto parts store or one of the major speed emporiums (Summit, Jeg's, etc.), you will almost undoubtedly get the new style which will leak. There are some sources that can probably supply the right part, but to be absolutely sure, you should get it from "Charlie ny" who is a member here and has probably forgotten more about 94's than most of us know.

tubman · 02-02-2020, 06:11 AM

Wayne, I believe it's better to try to diagnose a problem rather than just throw parts at it. You can check for a leaking power valve, by removing the air horn assembly from the carburetor and filling the bowl with fuel. Cover it with a rag or something (to inhibit evaporation) and let it sit overnight. If the fuel level is down significantly, you've found the culprit.

I'm not saying that this is your specific problem, but it's probably the most common cause of this sort of thing.

02-01-2020, 05:23 PM	#1
Wayne B Junior Member Join Date: Jan 2020 Posts: 10	1950 f3 Hello, New to the forum. I need a little help. Have a 1950 F3 with a rebuilt flathead, and converted to 12 volts. I can get the motor to start, but fouls the plugs and will not run correctly. Put in a fuel regulator to the carburetor and set it to 2.5 psi. There is no vacuum line now due to the new 12-volt distributor. Does anyone have any ideas?

02-01-2020, 05:39 PM	#2
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: 1950 f3 Welcome to the Barn Wayne. Sounds like a fuel problem, but. What type of distributor? Is it a modern one with a machinal advance or the original style? What are you referring to as a 12 volt distributor, normally a distributor doesn't care what voltage it sees. Is it an electronic distributor?

02-01-2020, 05:40 PM	#3
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,303	Re: 1950 f3 If it has a stock Holley 94 carburetor, I would immediately suspect a leaking power valve. Even if the carburetor has been rebuilt recently, it may be a problem. Currently available Holley power valves (for the 4BBL carbs) look like the older ones and even screw into the carburetor, but they are slightly different and do not seal correctly.

02-01-2020, 05:48 PM	#4
Wayne B Junior Member Join Date: Jan 2020 Posts: 10	Re: 1950 f3 The distributor in electronic with built in advance. I have the holley 94 carb. Seem like the carb is dumping fuel.

02-01-2020, 06:34 PM	#6
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,303	Re: 1950 f3 Sponsored Links (Register now to hide all advertisements) Again, it's probably a leaking power valve. I don't mean to be condescending, but do you know what a power valve in a 94 is, what it's for, and how it works?

02-01-2020, 06:39 PM	#7
Wayne B Junior Member Join Date: Jan 2020 Posts: 10	Re: 1950 f3 I’ve looked it up and ordered one. Hope this does the trick. Thanks

02-02-2020, 06:11 AM	#9
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,303	Re: 1950 f3 Wayne, I believe it's better to try to diagnose a problem rather than just throw parts at it. You can check for a leaking power valve, by removing the air horn assembly from the carburetor and filling the bowl with fuel. Cover it with a rag or something (to inhibit evaporation) and let it sit overnight. If the fuel level is down significantly, you've found the culprit. I'm not saying that this is your specific problem, but it's probably the most common cause of this sort of thing.