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'51 International fuel line

I just replaced the steel fuel line on my '51 International L110 pickup with a new one (with new double-flaired ends) because of a leak where the line meets the tank stub. I used some ether starting fluid to crank it up, because the fuel line, filter, and pump were (of course) dry. After a couple of good bursts on ether, the truck still didn’t start, and it doesn’t look like fuel made it up to the see-through filter yet. How long do I need to crank it on battery or ether before I can expect fuel to flow? Am I hurting the pump by running it dry?

That’s the original mechanical pump, then.
I wonder whether you don’t still have a very slight pinhole-sized leak in the fuel line somewhere and it is sucking air.
I doubt you’re hurting the pump by cranking it but you should get some fuel in there if you crank it for - say - 20 seconds or so. My 52 Dodge Truck takes that long, if it has been sitting for a while. You could fill the bowl with some gas but in your case it will just stall out when it runs out.

Nice truck, btw. IH trucks are very cool. Actually, all trucks of that vintage are very cool.

You are not hurting it, but some starting fluids have lubricants, I would check fuel pump diaphragm, a shot or 2 of starting fluid should be enough, how old is the gas?

Unless the carburetor fuel bowl was allowed to run dry there should already be enough fuel there to start the engine. Repeated use of ether is likely to harm the engine (or you!). Ether will wash the cylinder walls and allow the piston rings to run dry in the cylinder, wear will result. That’s why ether should only be used sparingly.

Were it me, I’d pour VERY small amounts of gasoline into the carburetor, rather than spray ether, and try to start the engine. You have to do this sparingly too, because gasoline carries the same hazards ether does, just not quite as bad. If it doesn’t start on the first or second try find out why.

Disconnect the fuel line at the carburetor and use a vacuum source to pull some fuel up to that point. Reconnect the line and fire it up…

Still no luck? Check the fuel pump for pressure and flow-rate…

Yes or no, the truck was running pretty normally before the fuel line replacement? When you pulled the line off the tank side, where did the gas go? Did you plug the fitting, or did you let the gas drain out of the tank? How strong was the flow if you let the tank drain? I’m wondering if the screen inside the tank is gunked up?

In the old days when you ran out of gas it would take a lot of cranking to bring fuel from the tank up to the engine. A little gas (one to two oz) poured down the carb would get you running for a few seconds, repeat and get a few seconds of running. After that there should be enough gas pulled up to keep it running without stalling.

Otherwise you are talking 40 to 90 seconds of cranking to bring the fuel up and that can be tough on an old starting motor.

Thanks for the ideas, everyone. The gas is about a month old by now, Barkydog. I had the tank removed and cleaned out professionally, and the truck ran fine with new fuel. There was a small resultant leak in the line/tankspur connection probably from over torquing the connection, so I decided to replace the line with one newly flaired. The line would drain out slowly when it sat for a few days, and then the truck wouldn’t start. When I removed the line, the tank was full, and there was fuel flowing out of the tank connection, but I just held my thumb over it until I capped it with a rubber tube temporarily while getting the new line. Assembling the new line also resulted in some fuel loss, but it was still flowing good when I sealed the connection, which doesn’t leak any more. So, line is new up to the transparent fuel filter, and was flowing well before being sealed. I guess I will just continue to crank it up, or perhaps try to pour fuel down the fuel line from the carb connection and see what happens. I have my fire extinguisher near by.

Unless you’ve converted to 12V, your 6V battery and starter kick over the motor pretty slowly. It will take a bunch of cranking to bring up the fuel, fill the clear filter and fill up the carb. If your fuel pump is old and a bit tired, even longer.

I’d use the fuel pour in the carb technique to speed up the process. The biggest risk is a backfire at the carb. If the truck is in good running shape and you only pour an ounce or so at a time it should work fine.

I can’t recommend this technique for a lot of reasons, but just a historical note. Back in the day we kept a small pump oil can (clean, all metal) with about a cup of gasoline in it. It was great when a spot of solvent was needed. It was also great for priming carburetors, particularly side drafts. A couple of squirts would get the engine running. A couple more as needed would keep the engine running quite a while.

@International Dave–I am unclear whether or not the truck fired up, even briefly, after you gave it a shot of ether. If it didn’t fire up at all, I am wondering if you knocked off an ignition wire while you were replacing the line. If it did fire up briefly on ether, then you aren’t getting gas to the carburetor.

Thanks again, folks. This is very helpful. I did convert it from 6V to 12V some time ago, Uncle Turbo (thought I wouldn’t mention it in case there are some diehard antiquees out there). And it did fire up on the ether for a few seconds, Triedaq, so I know it runs great. There is no fuel in the transparent fuel filter yet, so I know it is a fuel starvation problem. I probably will try cranking it several more times on ether, if necessary, to see if I can get fuel to move up the line. Based on your collective help, I think it either (a) takes a longer time, or (b) still has a pinhole problem.

Latest try; poured about 1cm of oil into the top end of the fuel pump, just to help it not be dry. Replaced the fuel filter since I had it out anyway. Added about 70ml gas to the carb bowl through the vent with an eyedropper. Started it on ether and it ran about 15 sec until the bowl fuel ran out. Repeat three more times. Still no fuel in the transparent filter. I think I may have a fuel pump problem. Before I replace the fuel pump, I may try pressurizing the tank just a little to push fuel up the fuel line. I would also measure the fuel pump suction if I had a suction gage (but I don’t). Sigh…

If you take the line off the fuel pump and dunk it into a container with gas that’s right under where the pump is, does it want to suck it up?
It really should be able to do that.

That’s a good way to check it without a suction gage, RemcoW. Thanks for that tip; I will try it.

That’s how I got my Rambler going. It had been parked since 76.
If your pump is one that has the glass bowl on the top, it may have a fuel filter in it. Mine was totally glazed over. I’d take that thing off first to make sure it is okay and you don’t suck gunk into the carb.

As stated previously I think the diaphram is shot in the fuel pump, it is a 6 dollar part, instead of buying a new pump!

That’s very possible.

Fuel pump diaphragms for 60 year old trucks that went out of production 40 years ago are still available for $6 ??..

I got one for my 66 evinrude a few years ago, called up NAPA too see about getting one for a 1 68 Nova with a 250, I do not even know if it is replaceable, they were happy to look it up, not available, but suggested they might be able to find a replacement if I brought it in. That was the price for the evinrude one, but you are probably right the price may be more. I do not know maybe it is a sealed unit and cant be replaced, leaping to conclusions and assumptions about that old truck. Diaphram can be checked

I replaced the entire fuel pump about 20 years ago; perhaps could have just replaced the diaphram. When I get a few minutes, I will crank it over and try sucking fuel from a bowl as a test, then (if a problem) replace the diaphram if I can get one. I got the fuel pump from NAPA 20 years ago for a 40 year old (at that time) truck, and a 12V version of the 6V heater motor besides. Nothing surprises me any more.

No glass on the top of the fuel pump, RemcoW. Transparent fuel filter is on the carberator side of the pump, so that’s probably a good thing. It was full of corrosion from the fuel tank prior to it being cleaned and the fuel line, which has been replaced. A good indicator that the fuel pump diaphram has had a difficult environment.