Gas Problem? Ideas? See video. Please help.

[PepeLoco]

What is going on? Got frustrated with what I thought was vapor lock. Come to a light, stop, then try to leave and it's starving for fuel hesitating or dying. When you look you see the inline gas filter empty. Prior to this I would notice air bubbles popping into the gas filter until all the gas was out. Then sometimes it would not fill back up and it would run really rough or die.

So I:
Pulled tank, no obstruction
Acid washed it in/out
Put in tank Screen filter and Electric valve
Clear temporary hose to see what's going on.
Removed inline filter
Gas cap has been off during these test runs
Temp readings on the carb were around 150, +/- 5 degrees f.
Day temp was around 100. Radiator around 150.

Reminds me of how you can hold a full beer bottle, upside down in a glass of beer.

I am thinking of installing a smaller diameter hose to act as a vent.
Is there suppose to be a vent on the top of the carb to the outside? the only one I saw from the inside top was a pin hole going to the fuel inlet. Nope, I did not check to see if that thing was open or plugged. Rats, may have to do that. Would that be the cause?

http://s1229.photobucket.com/albums/...t=Gasprobs.mp4

[steve s]

What you are "seeing" in the filter is not air; it is gasoline vapor, which looks the same as air. This is what vapor lock looks like. I have seen the same thing, except for me when the filter filled with vapor the flow would stop completely and motor would die. There is no way that air could make it down from the gas tank to the filter--and only do so on warm days!

There is a vent on the carb fuel bowl but it's not easy to see. The problem is that surface tension and insufficient fuel pressure from above is keeping the vapor bubble from getting that far. Some folks who have not seen this with their own eyes insist that it is not possible, so discussions can get a bit testy.

IMO, the first thing to try is simply remove the filter. For some, this is sufficient. For others, insulating the fuel line, crafting heat shields (I see you've already grasped at that straw), or changing carburetors has been required to avoid problems from vaporization in the sediment bowl, fuel line, and/or carb. Some folks report success by avoiding ethanolated gasoline, or by adding Marvel Mystery Oil or a guart or two of diesel/tank to the fuel, or by adding an electric fuel pump (preferably in a cool place). The dumbest thing I've seen reported to work is clipping a bunch of wooden clothes pins to the fuel line, as an alleged heat sink (!?).

Here's a photo of vapor bubble forming in my sediment bowl. It would periodically grow, run down the line, grow again, and again ..., without the running engine barely hiccuping.



Your video is much more compelling! Nice work!

Steve

[Fred]

First I would get rid of that carb, & that piece of metal just below intake.. Put on a GOOD Zenith with a copper gasket.. Next get rid of all the other stuff you just added..

[J Franklin]

It's time to adjust those valve clearances. An ice bag on the carb would do wonders.

[Mitch//pa]

is that aquarium hose your using for a fuel line?

[PepeLoco]

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Originally Posted by Fred

First I would get rid of that carb, & that piece of metal just below intake.. Put on a GOOD Zenith with a copper gasket.. Next get rid of all the other stuff you just added..

After I added that other stuff, I brought the carb temp down, a little and the performance improved (ironically). That heat shield really works. I have a Zenith and can try swapping them out. But it drives me crazy to figure out the root cause.

I appreciate the advice. Hey, what is the difference between a Zenith and a Tilly carb?

[Pickupman]

Originally Posted by Mitch//pa

is that aquarium hose your using for a fuel line?

Mitch, He states that he is using "Clear temporary hose to see what's going on."

[PepeLoco]

Originally Posted by Mitch//pa

is that aquarium hose your using for a fuel line?

OF COURSE NOT!!!!
It is left over from a beer bong! LOL!!!!!!!!!!!!!

Motorcycle fuel line. $15 from a Yamaha dealership.

[Mitch//pa]

Originally Posted by Pickupman

Mitch, He states that he is using "Clear temporary hose to see what's going on."

oh thanks i missed that one

[PepeLoco]

Originally Posted by J Franklin

It's time to adjust those valve clearances. An ice bag on the carb would do wonders.

I know. Need to adjust them as soon as I get this dang fuel prob in check. Otherwise I don't venture too far.

Ice bag? Seriously?
I did think of a saline drip bag from my past surgery, with the line running to the carb!!!!!!!!!

But you know what. I will take you up on that, I will do exactly that. Get an ice bag, strap it to the carb, drive till hot and shot the next vid.

[PepeLoco]

Originally Posted by J Franklin

It's time to adjust those valve clearances. An ice bag on the carb would do wonders.

[QUOTE=steve s;470002]What you are "seeing" in the filter is not air; it is gasoline vapor, which looks the same as air. This is what vapor lock looks like. I have seen the same thing, except for me when the filter filled with vapor the flow would stop completely and motor would die. There is no way that air could make it down from the gas tank to the filter--and only do so on warm days!

Ok Steve, how about this?
On the Aquarium fuel line, right at the carb, insert a "T" facing up with a hose running up above the fuel tank; keeping it about the fuel line.

Don't you think it should act as a vent tube and allow all the gas to flow unrestricted?

I even though of brazing a fitting at the tank to have this tube go back into the tank.

Your thoughts?

[oldredford]

The crap in the bottom of the glass bowl is ethanol water mixed fuel. Try pure gas. It happened to me....

[TinCup]

We have had goog luck wrapping the fuel line with 5/8 robber gas line as an insulator.

[steve s]

[QUOTE=PepeLoco;470041]

Originally Posted by steve s

What you are "seeing" in the filter is not air; it is gasoline vapor, which looks the same as air. This is what vapor lock looks like. I have seen the same thing, except for me when the filter filled with vapor the flow would stop completely and motor would die. There is no way that air could make it down from the gas tank to the filter--and only do so on warm days!

Ok Steve, how about this?
On the Aquarium fuel line, right at the carb, insert a "T" facing up with a hose running up above the fuel tank; keeping it about the fuel line.

Don't you think it should act as a vent tube and allow all the gas to flow unrestricted?

I even though of brazing a fitting at the tank to have this tube go back into the tank.

Your thoughts?

Thoughts: First, if you don't vent it to the fuel tank I'm not sure how you could get the end of this line above the top level of a full tank of gas without removing the hood--remember, it's going to fill up with liquid gasoline most of the time. Second, it sounds really scary--an open line venting gasoline liquid and sometimes fumes over the top of a hot motor. Third, you're a bold man considering tapping into the fuel tank. Fourth: not sure it would work anyhow--it looked like most of the vaporization was going on in the upper fuel line, which would be unaffected by the mod--also, I'm not sure but it looks like the carb may be dealing with the vapor ok, once it gets down there.

Steve

[steve s]

Originally Posted by oldredford

The crap in the bottom of the glass bowl is ethanol water mixed fuel. Try pure gas. It happened to me....

That may have been a bad picture. Here's a better one. Except for the vapor bubble in the top, the rest of the bowl was filled with a homogeneous clear liquid that looked exactly like gasoline.

[Fred]

Originally Posted by pepeloco

after i added that other stuff, i brought the carb temp down, a little and the performance improved (ironically). That heat shield really works. I have a zenith and can try swapping them out. But it drives me crazy to figure out the root cause.

I appreciate the advice. Hey, what is the difference between a zenith and a tilly carb?

answer: Your problems !!:d:d

[Jerry in Shasta]

Looks like to me the tilly's vent it plugged and it's trying to vent back thru the fuel line.
Just my W A G

JB

[frank55a]

Two suggestions:
1. Check how far the gas line extends past the farrel into the carb. This should only be a short amount, if to far the gas line will butt up against the filter in the carb and restrict your gas flow. You might first simply remove the filter in the carb and see if this helps.
2. Try about 4 oz Marvel Mystrey oil in a tank of gas. I always add it for a fill up. Drove back from Oshkosh in 95-100 degree temps across IL, IN, OH, and PA thru the mountains in western PA with no problems.

[[email protected]]

I just got this email today from a RockFord A's Club member I know. It is about one of the few gas stations around the area that don't have alcohol in their gasoline.

"I just gassed up at my neighborhood Beloit, WI station. The owners informed me that their distributor gave them manditory rules that their mid-price had to be now 10% ethynol by "law". That soon they will be forced to go to 20%. They had to change the labels on their pumps over the weekend. The low and Hi price are still regular gas.
They are very mad about this political change."

[sturgis 39]

The price of gasoline is going up. They can not meet the EPA mandates for ethanol because the drought has caused a big corn shortage. I guess we are going to import corn to make ethanol. Only the government bureaucrats and politicians can be this stupid.

Are you sure you have a vented gas cap? Some people switch them during the polishing process. Nice looking engine. I enjoyed the movie.

[PepeLoco]

Originally Posted by frank55a

Two suggestions:
1. Check how far the gas line extends past the farrel into the carb. This should only be a short amount, if to far the gas line will butt up against the filter in the carb and restrict your gas flow. You might first simply remove the filter in the carb and see if this helps.
2. Try about 4 oz Marvel Mystrey oil in a tank of gas. I always add it for a fill up. Drove back from Oshkosh in 95-100 degree temps across IL, IN, OH, and PA thru the mountains in western PA with no problems.

Frank, I thought the same thing and took it out long ago in this process.
I thought of the oil too, but we hear of reputable guys say they have never had nor seen vapor lock. This may not be vapor lock and not associated with the heat. I was going to take it for a spin after work and try to quantify the amount of air in that line during different engine and carb temps.

Thanks for the input.

[PepeLoco]

Sturgis,
I thought the cap might be an issue too, so I removed the cap during the testing.

Any other thoughts are hugely appreciated.

[BILL WILLIAMSON]

Someone posted recently that a ferrule fitted too deep at the sediment bowl can touch a "wall" inside & cause restricted flow?? Gotta' check that before I put on my new fuel line.
On my '30 that I sold, with standpipe filter in tank, cast iron sediment bowl, Zenith-2 carb, using only "Bad Bud's" crap gas, driving 200 miles + a week, I never had running problems or gum or goo or anything!! When draining cast iron sediment bowl, never got more than 2 or 3 water drops in a small baby food glass jar. Go figure that, I don't know either??? Before starting, I always pray, "Lord keep me safe & stopping well on this errand." Maybe that covers running well too????? Bill W.

[Kurt in NJ]

I am in the category of no visible "bubbles" in my fuel system, there has been a time that I thought I had "vapor lock", but it went away after I adjusted the points, although my car is near stock it has modified itself to give more carb heat to better vaporize fuel, and to compensate it has added more bowl vents in the form of a torn carb gasket ---with winter gas on a 95 degree day, long parade--idle speed for 1 hour ---then perhaps it is a little slow to get up to speed for a few seconds --then normal, the crack has exhaust blowing directly on the carb--you can feel it, i don't know what the carb temp is but you sure can't hold your hand on it.

the fuel pipe has had the burr removed from the end where the pipe was cut, the screens are original ,jets,float valve,float also original---cast iron sediment bowl (prove that it has a bubble in it)---nothing to worry about, no bubbles to see --therefor no problem

Yes I probably have gas boiling in the carb sometimes, but the car drives through it.

Have you tried having everything stock with original ford parts ---no modifications ???

I built the car stock, very few modifications ( B cam, diode cutout, Quartz Halogen headlight bulbs), since then it has thrived on neglect and been very reliable--other than for the halogen headlight bulbs it's the same as it got the blue ribbon in the 80s

have you tried the original fuel line routing using steel pipe, no low spots, gentle slope in horizontal runs ---no inline filter ( it is interesting, am working on a BMW Isetta the parts place for them warned me that I should never use a paper filter, that it would cause "vapor lock", this car also has a gravity system.) ---the stock screens won't pass anything large enough to easily clog a jet, too fine of a filter can restrict flow.

[BILL WILLIAMSON]

Has anyone ran with no hood for a long length of time when weather is extremely hot? Bill W.

[sturgis 39]

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[QUOTE=BILL WILLIAMSON;470866]Has anyone ran with no hood for a long length of time when weather is extremely hot? Bill W.[/QUOT


The first or second thing my brother and I did was to remove the hood. That was about ten years ago. The hood has not been on the car since we removed it. The car always over heated until we installed a new Brass Works Radiator. I never had a so called "Vapor Lock". We had a lot of plugged fuel filters. The gas tank was cleaned several times by a radiator shop. There are baffles in the tank that prevent the removal of all the rust flakes. We installed a stand pipe in the gas shut off valve and that seems to keep the big chunks out of the filters. We installed a see through filter between the shut off valve and the sediment bowl on the fire wall. It catches a lot of junk. The sediment bowl seems to collect some moisture. The little filter on the carburetor fuel inlet is always clean.

I think the car runs cooler without the hood. I run a two bladed fan because they look cool.

[Brobrian]

Wow, I love the heat shield. I was revving my motor at a stop light in 100+ heat the other day and told myself I would have to make just such a thing. And I'm goin to try to shield the floorboard while I'm at it.
Just saying, I like your enginuity!