Yote
Well-Known Member
Yes, I was able to see the fuel swirling in the carburetor throat last week. That is when I started to research my issue but was not looking at the time the car died only a couple minutes before.
Runs then dies
- Thread starter Yote
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I get the idea of adding an electric pump. Technology is great, but the fact of it is, if some of yall are having to add electric pumps to fix a problem, yall got something WRONG.
Sounds like a failing fuel pump, or a venting issue. As mentioned above, remove the gas cap and see if that changes anything. If it does not, I would replace the pump. By the way, the rubber hose that connects your metal fuel line to the pump inlet: if you squeeze the rubber, is it firm or very soft? If soft, I would replace that piece for sure and re-test.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Another thing to check is the short jumper, at the back, from the sender to the hard line. It doesn't usually leak because it is above the Liquid line.
Here's my take on what happens;
if your pump is sucking air there, it will pump it up stream into the carb. Thus the pump loses it's prime. After the car stalls, the fuel in the supply line comes together in the lowest part of the line, and with a lil cranking, the pump gets it's prime back. But now the pump is working overtime to fill the line ahead of it, and so once the carb is filled, you get another block of time out of it. Then with the pump idling again, it starts to pull air again. Or maybe I should say, the pump begins to pull more air as a percentage of the total of what it's pulling If she starts to get 30/40 or 50 percent air, well, you get the picture. Sooner or later the pump will starve.
Here's my take on what happens;
if your pump is sucking air there, it will pump it up stream into the carb. Thus the pump loses it's prime. After the car stalls, the fuel in the supply line comes together in the lowest part of the line, and with a lil cranking, the pump gets it's prime back. But now the pump is working overtime to fill the line ahead of it, and so once the carb is filled, you get another block of time out of it. Then with the pump idling again, it starts to pull air again. Or maybe I should say, the pump begins to pull more air as a percentage of the total of what it's pulling If she starts to get 30/40 or 50 percent air, well, you get the picture. Sooner or later the pump will starve.
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Yote
Well-Known Member
Thanks AJ checked that last week. All lines near new and connections good.
Couldn’t agree with you more Rusty, just with my knowledge I am at a near standstill. Sorry I overlooked a previous question from you. My tach for under hood use died last week and with no help could not read one in car, but 37’ total was all I could get. I don’t know at what rpm it came in at.
Couldn’t agree with you more Rusty, just with my knowledge I am at a near standstill. Sorry I overlooked a previous question from you. My tach for under hood use died last week and with no help could not read one in car, but 37’ total was all I could get. I don’t know at what rpm it came in at.
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AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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What kind of clamps are on your new jumper at the back?
If gear clamps, it has happened to me that one clamp on each side, still sucked air there. So I put two on each side with the screwheads clocked 180*. That solved my problem. For me, the tell-tale was the filter kept filling up with air.
On another job, the tank was vented forward to the charcoal canister. That line was only very small, and it had rusted nearly fully closed under the passenger seat, the lowest place in the line. The cap was non-vented. So the car ran until pump could no longer pull fuel from the tank. When the car stalled, if you waited a few minutes, the vacuum in the tank would slowly pull air from the canister and equalize to atmospheric. And then the pump would pull again ........... for awhile.
I cut a couple of feet of the vent-line out and put a temporary jumper across, which solved the problem. Then I made a permanent repair.
On another job, the fuel seemed to be boiling in the pump or in the line from the pump to the carb. So I installed one of those in-line filters with the sideways third nipple, and plumbed that to the vent line back to the tank, then installed a vented cap; problem solved.
On another job, the return-spring on the arm inside the pump was too weak to keep the arm on the eccentric. So she pumped ok at low rpm, but as the Rs climbed, the pump quit pumping. That was a toughie, cuz it tested good at cranking and idle. It looked the same as a plugged vent. With the fuel-bowl empty the fuel in the line from the carb back to the pump would boil and the filter presented as empty.
Good luck
If gear clamps, it has happened to me that one clamp on each side, still sucked air there. So I put two on each side with the screwheads clocked 180*. That solved my problem. For me, the tell-tale was the filter kept filling up with air.
On another job, the tank was vented forward to the charcoal canister. That line was only very small, and it had rusted nearly fully closed under the passenger seat, the lowest place in the line. The cap was non-vented. So the car ran until pump could no longer pull fuel from the tank. When the car stalled, if you waited a few minutes, the vacuum in the tank would slowly pull air from the canister and equalize to atmospheric. And then the pump would pull again ........... for awhile.
I cut a couple of feet of the vent-line out and put a temporary jumper across, which solved the problem. Then I made a permanent repair.
On another job, the fuel seemed to be boiling in the pump or in the line from the pump to the carb. So I installed one of those in-line filters with the sideways third nipple, and plumbed that to the vent line back to the tank, then installed a vented cap; problem solved.
On another job, the return-spring on the arm inside the pump was too weak to keep the arm on the eccentric. So she pumped ok at low rpm, but as the Rs climbed, the pump quit pumping. That was a toughie, cuz it tested good at cranking and idle. It looked the same as a plugged vent. With the fuel-bowl empty the fuel in the line from the carb back to the pump would boil and the filter presented as empty.
Good luck
mygasser
Well-Known Member
i can't see the amount of ignition advance being related as it was fine before with that timing. so although it may be too much it's not this problem.
Yote
Well-Known Member
Have decided to do (for me) the unthinkable. Removed the carb and started disassembly as my semi-adult mind finally thinks it’s flooding out. Will reread all your posts to see if I can find out why. Am done for today, will see what tomorrow brings.
Yote
Yote
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