318 down

[Intrepolicious]

Of course I should probably wait until it's almost empty lol

I made that mistake once with my LH body.

 

[AJ/FormS]

I think you should replace the jumper at the back and quadruple clamp it, and if you already have done that, then take the cap off and throw it in the trunk for an hour.
What I think, with twice at the same-ish liquid level,either the pump is sucking air or the tank is not venting.
And before you replace the pump, do a volume output test. If you have to take it off,check the arm return spring first, before condemning it..
If there is junk in the tank, that makes it thru the sock it will end up in the filter.If it makes it thru the filter, you are in need of a better filter. Fine powder that makes it thru the filter while uncommon to me is a non-issue; it will coat the bottom of the bowl, no big deal. And if it makes it into the slow-speed system, it is too small to do any damage. It is iron oxide, it burns in the chamber.It makes a nice bright flash and then it is consumed.
If removing the cap solves the problem, you will have to troubleshoot the venting system.
Those are the things I would do.

 

[Intrepolicious]

Well, she started up after work for a minute then died before I could ever leave the parking lot. Now she won't start at all.. vapor locked? I had to quit trying to crank her before I killed my battery (and starter!)

 

[Intrepolicious]

AJ, when you say "jumper at the back".. where exactly is that? On top of the tank?

I think you should replace the jumper at the back and quadruple clamp it, and if you already have done that, then take the cap off and throw it in the trunk for an hour.
What I think, with twice at the same-ish liquid level,either the pump is sucking air or the tank is not venting.
And before you replace the pump, do a volume output test. If you have to take it off,check the arm return spring first, before condemning it..
If there is junk in the tank, that makes it thru the sock it will end up in the filter.If it makes it thru the filter, you are in need of a better filter. Fine powder that makes it thru the filter while uncommon to me is a non-issue; it will coat the bottom of the bowl, no big deal. And if it makes it into the slow-speed system, it is too small to do any damage. It is iron oxide, it burns in the chamber.It makes a nice bright flash and then it is consumed.
If removing the cap solves the problem, you will have to troubleshoot the venting system.
Those are the things I would do.

 

[Intrepolicious]

After it sat for a while then it decides to start

 

[Intrepolicious]

Totally just like last time. Now she's home and starting right up, like nothing ever happened lol.

 

[Intrepolicious]

I guess I could just start replacing stuff. One at a time, fuel pump, fuel lines, tank, carb the whole schlameele?

 

[Intrepolicious]

I'll try the volume test on the pump tomorrow AJ. I do appreciate your knowledge and your help! Tomorrow I'll have time to pull that alternator out of the way and go to town.

 

[BudW]

Two items popped up in my head.

If engine is running hot (carburetor too hot to touch after turn off), sometimes fuel can percolate out of the carburetor bowl. Generally fuel will remain in the accelerator pump circuit – so you have one or two shots of fuel - but other than that, it takes a while for fuel to re-fill the fuel bowl before car will run (vapor lock).

Second thought is if you have a rusty fuel line or cracked fuel hose, an air pocket will develop in fuel line. Fuel pumps prefer to pump liquid and not air, and it takes a while to pump air before fuel gets where it needs to go. Generally the fuel line after pump to carburetor still has fuel as well as fuel in carburetor – so maybe 15 seconds of fuel (or more) after startup, maybe?

Might even have both conditions.
BudW

 

[AJ/FormS]

AJ, when you say "jumper at the back".. where exactly is that? On top of the tank?

This is the 4" or so short rubber hose that jumps from the tank sending unit to the main line. From the factory there is one flat band spring clamp on each side. These are the best. If they are no longer there, then gearclamps will work. Install two on each side and stagger the screws 180*. Do not over-tighten them.
When this jumper rots, it may not leak fuel cuz it is higher than the liquid in the tank. But the pump will suck air here, along with whatever fuel it picks up from the full tank. As the fuel level in the tank drops, it becomes harder and harder for the pump to lift the fuel up and over, so eventually the pump only pulls air, and everything comes to a halt. If the venting system also is not working, then this is likely to occur early and often.Remember, atmospheric air in the tank is what pushes the fuel up into the line. No air,equals no push.
When you let it sit, all the air in all the lines rises up towards the ends, and all the fuel settles in the low spots, and the tank pressure equalizes with the atmosphere. If the tank vent is completely plugged, then the tank may become pressurized by vapor pressure, which is the same process which makes your plastic jerry-cans swell up in the sun.
So now you go to start it and vapor pressure is forcing the fuel along in response to the pumps pull. Pretty soon the pump has got a prime and it fills the bowl, and the engine springs to life. So off you go happy as can be. Some undetermined time later, depending on many factors, the vapor pressure may drop to zero, and the pump starts pulling air, and the whole thing crashes again. And that's why I said

I think you should replace the jumper at the back and quadruple clamp it, and if you already have done that, then take the cap off and throw it in the trunk for an hour.

I'm not saying this is or these are your problems, but I do think there is a very strong possibility. The tiny steel line that vents to the charcoal canister is well known to rust up, and the jumper doesn't last forever.

 

[Intrepolicious]

This is the 4" or so short rubber hose that jumps from the tank sending unit to the main line. From the factory there is one flat band spring clamp on each side. These are the best. If they are no longer there, then gearclamps will work. Install two on each side and stagger the screws 180*. Do not over-tighten them.
When this jumper rots, it may not leak fuel cuz it is higher than the liquid in the tank. But the pump will suck air here, along with whatever fuel it picks up from the full tank. As the fuel level in the tank drops, it becomes harder and harder for the pump to lift the fuel up and over, so eventually the pump only pulls air, and everything comes to a halt. If the venting system also is not working, then this is likely to occur early and often.Remember, atmospheric air in the tank is what pushes the fuel up into the line. No air,equals no push.
When you let it sit, all the air in all the lines rises up towards the ends, and all the fuel settles in the low spots, and the tank pressure equalizes with the atmosphere. If the tank vent is completely plugged, then the tank may become pressurized by vapor pressure, which is the same process which makes your plastic jerry-cans swell up in the sun.
So now you go to start it and vapor pressure is forcing the fuel along in response to the pumps pull. Pretty soon the pump has got a prime and it fills the bowl, and the engine springs to life. So off you go happy as can be. Some undetermined time later, depending on many factors, the vapor pressure may drop to zero, and the pump starts pulling air, and the whole thing crashes again. And that's why I said

I'm not saying this is or these are your problems, but I do think there is a very strong possibility. The tiny steel line that vents to the charcoal canister is well known to rust up, and the jumper doesn't last forever.

Thanks AJ. Can that jumper be accessed without pulling the tank?

And say I wanted to replace the lines, is there a good source?

 

[Intrepolicious]

I'm not saying this is or these are your problems, but I do think there is a very strong possibility.

The way you describe it, it sure sounds like it. Especially because the same exact thing happened before with this specific amount of gas in the tank.

 

[Intrepolicious]

Two items popped up in my head.

If engine is running hot (carburetor too hot to touch after turn off), sometimes fuel can percolate out of the carburetor bowl. Generally fuel will remain in the accelerator pump circuit – so you have one or two shots of fuel - but other than that, it takes a while for fuel to re-fill the fuel bowl before car will run (vapor lock).

Second thought is if you have a rusty fuel line or cracked fuel hose, an air pocket will develop in fuel line. Fuel pumps prefer to pump liquid and not air, and it takes a while to pump air before fuel gets where it needs to go. Generally the fuel line after pump to carburetor still has fuel as well as fuel in carburetor – so maybe 15 seconds of fuel (or more) after startup, maybe?

Might even have both conditions.
BudW

I think your 2nd thought is spot on with AJ's. I'm going to have to take a look at this jumper.

I get you on the vaporlock thing too, but I don't think it's been running hot. Sometimes this happens very soon after I start her up.

 

[Intrepolicious]

This is the 4" or so short rubber hose that jumps from the tank sending unit to the main line. From the factory there is one flat band spring clamp on each side. These are the best. If they are no longer there, then gearclamps will work. Install two on each side and stagger the screws 180*. Do not over-tighten them.

I don't suppose you've got a picture of this do you AJ? Again, do I need to drop the tank?

If I need to drop the tank, I'm going to have to empty it out.. I suppose I could siphon it out.

 

[Intrepolicious]

Well, I got off my lazy butt and went and looked. Yes, I'll definitely have to drop the tank to get to this jumper.

Too bad they didn't make an access panel in the trunk.

AJ, do you think a vented gas cap might alleviate some of these vapor locking issues for the time being?

 

[Intrepolicious]

I'm off today, so I'm gonna try to drive it around and run the tank down. I've unplugged the vent line to the charcoal canister. Let's see if that makes any difference.

I'm obviously going to have to drop the fuel tank to get to these lines (that jumper) etc.

Well, I got off my lazy butt and went and looked. Yes, I'll definitely have to drop the tank to get to this jumper.

Too bad they didn't make an access panel in the trunk.

AJ, do you think a vented gas cap might alleviate some of these vapor locking issues for the time being?

I realize that the gas cap I have is "vented" but wonder if it's working right.. when I remove it, it's definitely releasing a lot of pressure. Like a soda bottle!

 

[Intrepolicious]

Well, she's definitely got some issues with the fuel delivery. Multiple stalls around the neighborhood. Had to sit around the corner for a good 30 minutes before she'd start up again. Got her back to the house.. it's weird. I guess I'm gonna have to siphon the gas out of the tank, and drop it.

Might not be today.. the family is getting hungry and irritable. In the meantime, I need to look at replacement lines like that jumper for one.

What about the sending unit itself AJ?

 

[Intrepolicious]

Oh and unplugging the vent line to the charcoal canister didn't make any changes...

 

[AJ/FormS]

Well, I got off my lazy butt and went and looked. Yes, I'll definitely have to drop the tank to get to this jumper.

Too bad they didn't make an access panel in the trunk.

AJ, do you think a vented gas cap might alleviate some of these vapor locking issues for the time being?

Could go either way, depending on the jumper,
>But before you drop the tank, you have got to prove a couple of things, namely that it is in fact a fuel issue. If you drop that tank and find nothing wrong, you are gonna be one unhappy guy, and I and everyone else is gonna hear about it.
You haven't proved anything yet. I, and Bud, and others, are just throwing out ideas based on our experiences.Somebody still has to prove it, and I'm not the one,lol.
Besides, you may be experiencing multiple issues.
>An engine needs 7 things to run. You already know about 3 of them,namely fuel, air, and spark.Besides these; it needs compression,a reasonably close AFR, she needs to process air OUT as well as in,and everything has to work according to the designers plan.
>Since you drove it a fair ways before it croaked; It just did have all 7 of those. In your case, the most likely culprits are; a failed spark,or no fuel.Both of these are easy to prove. Spark is easiest.
So, the next time she croakes,immediately go check for spark.This is so easy.
And if it's there, then you check the carb for fuel.
>And just cuz when you pump it, something comes out the squirters, doesn't prove the bowl is full, and even if it was, What is it full of? Just cuz you pulled up to the gas bowser and filled up, exactly what went into the tank? You believe it was gas, cuz you've done it probably thousands of times. But was it 100% gas? People believe lotsa things, that doesn't make it true. People believe the earth is a ball
So where was I? Oh, yeah, gas. Gasoline with alcohol in it, has an affinity for water. But the water doesn't bond to the gas,it lays in the bottom of the suppliers tank, and they are supposed to monitor that, and get rid of it; not all do. So along comes you and, on this particular day, you are Mr.Unlucky, #72, and your bowser sucks some up, and dutifully deposits it in your tank. Such a mindless device, just doing what it was designed to do. Ok so now you have a splash of water in your tank.And it migrates to the low spot. And over night it freezes there. Next morning,along comes Mr.Unlucky #72 and starts her up. After three minutes or so, he puts it in gear and drives away, not knowing that the pick-up sock in his tank is severely restricted by the blob of frozen water. The pump tries to keep up, but you are burning it faster than it can find it, so eventually the jets find no more gas, and everything screeches to a halt. But your accelerator pump still has gas in it, and after about 5 pumps, low and behold, she sputters to life.Now while the engine was stalled, perhaps a bit of vacuum remained in the line, and some gas moved down to the pump. Or perhaps there was a bit of ice in the line, and the gas found it's way around it. In any case, now there is a slug of gas sitting close to the pump. You pump and crank and pump and crank,and low and behold she fires up. Hallelujah, we're going home! Well, this time you only drive half as far, and then it starts all over.
>Ok, but what if it didn't freeze overnight? Well then, gasoline engines don't run on water. So, that splash of water finds it's way to the pick-up overnight, and next morning, the pump picks some of it up along with some gas and delivers to the carb.Eventually the water level gets high enough, and the jets pick up a bit of it, and you might feel a shudder as it passes through. Suddenly a whole big slug enters the carb, and it's game over.
But you Mr.Unlucky#72, don't know what's going on. So you pump and crank and pump and crank, and eventually you have pumped all the water down the hatch, and the engine sputters to life on the gas coming up the pipe. Hallelujah we're going home!. And so it goes until the next slug of water comes along.
>Now, I'm not saying this is what's going on,exactly. But I have seen it many times up here, especially at the turn of the seasons.
>So the next thing would be to see what is actually in the carb, at the time it stalls. Water separates out of the gas pretty quick. If you were to put equal parts of water and gas into a jar and shake it all about,then set it down; most of the water will settle out in a few seconds. If you were to take the top of the carb off, you would see it in there,rolling around in the bottom of the bowl, with lots of gas above it.It looks really neat. If you were to install a semi-transparent fuel filter in the line, you would see it in there too.If you orient the filter with one end higher than the other, then you have a convenient place to drain that chit. Of course the bowl will still have water in it. And certain carbs will not pump it out because of the way the pump works. So the answer to that is to splash a little gas down the holes, get in, push the pedal about 2/3 of the way to the floor, and crank it. Keep the pedal down far enough to keep the revs above 2000 and just let her clean herself out. Repeat as often as necessary. What you are doing is bypassing the MJs, while they are delivering nothing but water.Eventually,the water will all have passed thru, and the engine will stop stalling, and then you can let her idle down. Now Hallelujah, drive! If it happens again, you will see the water in that fancy plastic filter, and you will know exactly what to do.
>There is another solution.There is a way to bond that water to the gasoline, and it will pass harmlessly through the jets while driving. It's called Gasline-Antifreeze, oddly enough. But there are two kinds, and only one of these can do this. It is called IsoPropyl Alcohol. Buy a couple of small cans,dump it in and see if your problems go away.If they are history, find a different filling station.
So
that's another scenario.

 

[Intrepolicious]

Could go either way, depending on the jumper,
But before you drop the tank, you have got to prove a couple of things, namely that it is in fact a fuel issue. If you drop that tank and find nothing wrong, you are gonna be one unhappy guy, and I and everyone else is gonna hear about it.
You haven't proved anything yet. I, and Bud, and others, are just throwing out ideas based on our experiences.Somebody still has to prove it, and I'm not the one,lol.
Besides, you may be experiencing multiple issues.
An engine needs 7 things to run. You already know about 3 of them,namely fuel air and spark.Besides these; it needs compression,a reasonably close AFR, she needs to process air OUT as well as in,and everything has to work according to the designers plan.
Since you drove it a fair ways before it croaked; It just did have all 7 of those. In your case, the most likely culprits are; a failed spark,or no fuel.Both of these are easy to prove. Spark is easiest.
So, the next time she croakes,immediately go check for spark.This is so easy.
And if it's there, then you check the carb for fuel. And just cuz when you pump it, something comes out the squirters, doesn't prove the bowl is full, and even if it was, What is it full of? Just cuz you pulled up to the gas bowser and filled up, exactly what went into the tank. You believe it was gas, cuz you've done it probably thousands of times. But was it 100% gas? People believe lotsa things, that doesn't make it true. People believe the earth is a ball

to be continued, I got company

I hear ya about the stuff that comes out of the pump at the corner store lol... they said it was gas anyways! There's a place here in town that sells "ethanol free" gas for "off road use". maybe I should run a tank of that through it next.

Don't worry, I'm not going to go snatch the tank out of there all willy nilly just yet. And don't worry, I understand what you guys post are merely suggestions based on your own previous experiences. I get it.. there are no guarantees, and anything I do to my car is at my own risk and I have nobody to blame when something doesn't work or fix my problem other than myself.

The last time it croaked, I checked for and confirmed spark, so I know it's getting spark and these plugs are brand new. So with spark proven and out of the way, fuel. It could be the jumper as you suggest. Or it could be the carb getting hot like Bud suggested and maybe I just need a non-heat-conducting spacer, or to insulate the lines. Your ideas and thoughts on the problem are a huge help in guiding me into what to look for. With your input, I'm learning about how these fuel systems work and I'll be able to pinpoint the issue eventually.

So, I'll be back at it probably tomorrow, as likewise, company and the family need my attention.