The Ford Barn

Rustynutz52 · 03-20-2014, 06:23 PM

My 39's carb is giving me a fit. It seems to loose all the fuel in the bowl after a few days. I have changed power valve twice with the same outcome. Any thoughts as to why it might be going dry. It is a 94 carb. 91-99. Any other areas of potential leak down? Car could not run better then it does smooth as glass at idle and no flat spots. Its about to drive me crazy.

ford38v8 · 03-20-2014, 06:35 PM

Rusty, it's the corn gas. It evaporates faster than you can blink an eye.

Rustynutz52 · 03-20-2014, 06:36 PM

I am fortunate to live near a lake and can get ethanol free. I cant figure the darn thing out.

ford38v8 · 03-20-2014, 06:42 PM

Ethanol is corn gas.

Vic Piano · 03-20-2014, 07:01 PM

Alan, I'm sure he meant he gets ethanol-free gas, not get ethanol gas free... LOL

trainguy · 03-20-2014, 07:12 PM

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Some of the modern power valves have a problem seating in the carb.I believe that the carb restorers face the seating surface of the PV to achieve the seal.

ford38v8 · 03-20-2014, 07:14 PM

Vic, I think you're right. Still, ethanol or not, i believe the formulation is more volatile than in the past. They make fuel these days for EFI, not carbs.

Tinker · 03-20-2014, 07:26 PM

When you put the car away pour about a bowls worth of gas that you are using in a jar and set it somewhere in the garage (open). I tried it and with about a quart of non-eth gas over a month, interesting. See if it goes dry the next time you fire the car. Fuel does evaporate quickly. But I would lean to what the trainguy said, if it goes dry after a few days.

Vic Piano · 03-20-2014, 07:47 PM

Quote:

Originally Posted by ford38v8

Vic, I think you're right. Still, ethanol or not, i believe the formulation is more volatile than in the past. They make fuel these days for EFI, not carbs.

Alan, you are 100% correct about the "corn" gas, it plays hell with carbs, fuel pumps, etc.

I haven't had an opportunity to fill up any of our vintage vehicles with non-corn gas, so I can't make a comparison.

flatjack9 · 03-20-2014, 08:25 PM

Remove the carb, fill it with gas and set it on the bench and see if it leaks out and where.

JT FORD · 03-20-2014, 08:28 PM

When you shut it off, pull the choke all the way out. That gets you some more time before it goes dry. If its leaking out that will not help........

41ford1 · 03-20-2014, 08:40 PM

Trainguy has the most likely issue. The gasket that is commonly provided with the modern PVs have a triangular shape ID. These do not seal well on early 94s. You need a gasket the same ID and OD of the carb seating surface.

To be sure do what flatjack9 says. Do the test also without the throttle body on. You will readily see if the PV is leaking.

1952henry · 03-20-2014, 08:47 PM

Quote:

Originally Posted by flatjack9

Remove the carb, fill it with gas and set it on the bench and see if it leaks out and where.

Bingo!

'Tis not that the gas is formulated for EFI, it is formulated in accordance with the EPA.

And, back in the 80s when ethanol first became an option, many folks in the midwest used it with no problems. My father was one of them. First car he used it in had 30,000 miles or so on it when he switched. NO problems! One caveat, he put 100+ miles a day on his cars, so the gas didn't sit too long in them.

Bolts · 03-20-2014, 10:09 PM

Quote:

Originally Posted by Vic Piano

Alan, I'm sure he meant he gets ethanol-free gas, not get ethanol gas free... LOL

That was funny!

Bolts · 03-20-2014, 10:12 PM

Quote:

Originally Posted by flatjack9

Remove the carb, fill it with gas and set it on the bench and see if it leaks out and where.

Excellent suggestion flatjack9.

Charlie ny · 03-21-2014, 12:17 AM

Rusty,
Machining the gasket face on the carb and bowl helps, if you have leak a problem.
A few days is the new normal in my opinion if your situation is evaporation related.
You need a good fuel pump for sure....ever wonder why even concourse cars have
an elect fuel pump hidden up near the tank. I sent you a PM.
Charlie ny

Charlie ny · 03-21-2014, 01:02 AM

Rusty,
First sentence should read......Machining the power valve gasket face
on the PV and bowl helps.....
Charlie ny

Rocketsled · 03-21-2014, 03:15 PM

Use chrush washers under the power valve to get the orifice on the correct plane.

03-20-2014, 06:23 PM	#1
Rustynutz52 Member Join Date: Apr 2013 Location: Lake Wylie South Carolina Posts: 76	Holley 94 dry after sitting few days My 39's carb is giving me a fit. It seems to loose all the fuel in the bowl after a few days. I have changed power valve twice with the same outcome. Any thoughts as to why it might be going dry. It is a 94 carb. 91-99. Any other areas of potential leak down? Car could not run better then it does smooth as glass at idle and no flat spots. Its about to drive me crazy.

03-20-2014, 06:35 PM	#2
ford38v8 Senior Member Join Date: Jul 2011 Location: SF Bay Area Posts: 6,635	Re: Holley 94 dry after sitting few days Rusty, it's the corn gas. It evaporates faster than you can blink an eye. __________________ Alan

03-20-2014, 06:36 PM	#3
Rustynutz52 Member Join Date: Apr 2013 Location: Lake Wylie South Carolina Posts: 76	Re: Holley 94 dry after sitting few days I am fortunate to live near a lake and can get ethanol free. I cant figure the darn thing out.

03-20-2014, 06:42 PM	#4
ford38v8 Senior Member Join Date: Jul 2011 Location: SF Bay Area Posts: 6,635	Re: Holley 94 dry after sitting few days Ethanol is corn gas. __________________ Alan

03-20-2014, 07:01 PM	#5
Vic Piano Senior Member Join Date: May 2010 Location: Odessa, FL Posts: 7,611	Re: Holley 94 dry after sitting few days Alan, I'm sure he meant he gets ethanol-free gas, not get ethanol gas free... LOL __________________ Imagination is more important than knowledge.

03-20-2014, 07:12 PM	#6
trainguy Senior Member Join Date: May 2010 Location: Lehighton Pa Posts: 1,085	Re: Holley 94 dry after sitting few days Sponsored Links (Register now to hide all advertisements) Some of the modern power valves have a problem seating in the carb.I believe that the carb restorers face the seating surface of the PV to achieve the seal.

03-20-2014, 07:14 PM	#7
ford38v8 Senior Member Join Date: Jul 2011 Location: SF Bay Area Posts: 6,635	Re: Holley 94 dry after sitting few days Vic, I think you're right. Still, ethanol or not, i believe the formulation is more volatile than in the past. They make fuel these days for EFI, not carbs. __________________ Alan

03-20-2014, 07:26 PM	#8
Tinker Senior Member Join Date: May 2010 Location: MN Posts: 7,053	Re: Holley 94 dry after sitting few days When you put the car away pour about a bowls worth of gas that you are using in a jar and set it somewhere in the garage (open). I tried it and with about a quart of non-eth gas over a month, interesting. See if it goes dry the next time you fire the car. Fuel does evaporate quickly. But I would lean to what the trainguy said, if it goes dry after a few days.

03-20-2014, 08:25 PM	#10
flatjack9 Senior Member Join Date: May 2010 Location: Oshkosh, Wi Posts: 4,526	Re: Holley 94 dry after sitting few days Remove the carb, fill it with gas and set it on the bench and see if it leaks out and where.

03-20-2014, 08:28 PM	#11
JT FORD Senior Member Join Date: May 2010 Location: N.W. Iowa Posts: 306	Re: Holley 94 dry after sitting few days When you shut it off, pull the choke all the way out. That gets you some more time before it goes dry. If its leaking out that will not help........

03-20-2014, 08:40 PM	#12
41ford1 Senior Member Join Date: May 2010 Location: ManchVegas, New Hampshah Posts: 1,589	Re: Holley 94 dry after sitting few days Trainguy has the most likely issue. The gasket that is commonly provided with the modern PVs have a triangular shape ID. These do not seal well on early 94s. You need a gasket the same ID and OD of the carb seating surface. To be sure do what flatjack9 says. Do the test also without the throttle body on. You will readily see if the PV is leaking. __________________ You are never to old to enjoy your childhood. Forty1fordpickup on the HAMB.

03-21-2014, 12:17 AM	#16
Charlie ny BANNED Join Date: May 2010 Posts: 3,019	Re: Holley 94 dry after sitting few days Rusty, Machining the gasket face on the carb and bowl helps, if you have leak a problem. A few days is the new normal in my opinion if your situation is evaporation related. You need a good fuel pump for sure....ever wonder why even concourse cars have an elect fuel pump hidden up near the tank. I sent you a PM. Charlie ny

03-21-2014, 01:02 AM	#17
Charlie ny BANNED Join Date: May 2010 Posts: 3,019	Re: Holley 94 dry after sitting few days Rusty, First sentence should read......Machining the power valve gasket face on the PV and bowl helps..... Charlie ny

03-21-2014, 03:15 PM	#18
Rocketsled Senior Member Join Date: May 2010 Location: Wakefield, N.H. USA Posts: 142	Re: Holley 94 dry after sitting few days Use chrush washers under the power valve to get the orifice on the correct plane.