more fuel problems... fixed the rockin and rolling fuel tank on the war wagon. but it still is starving for fuel. i think the fuel line from the sending unit to the transfer to the solid line is sucking shut. its about 2 and a half feet long and it feels pretty spongy. like it pinches shut pretty easy like its silicone or something... and 40 some-odd years old. so i called my friend at advance and they have some high pressure fuel line for fuel injection that has steel braiding that is 7 dollars a foot. and the regular ol 3/8 rubber fuel line that is pretty cheap. what do you guys think is the better choice? that tank is a pain in the neck to drop and id like to only do it once. is the high pressure stuff less likely to suck shut under a vacumn than the regular fuel line? ive never had a problem with regular fuel line but i hate to redo jobs ya know? discuss!
Try to reduce the length of the rubber hose to 4-5" overall at each junction - Run some 3/8" brake line in between -- flare slightly at each end
I agree . Way too much fuel line . Replace with stock fuel line but no more the 6" for safety ! Don't need high tech costly fuel line . The regular fuel line works fine . Use steel line in-between the splices . Retro Jim
as others have said , the least rubber line the better, but as a test to see if that is your problem you could just run the length of regular fuel line. there shouldn't be any vacuum in your line or tank, the things that will cause this are as you have stated, a very old spongy fuel line in combination with a non-venting cap if your tank doesn't have one. As well is your tank tank is old and has rust and silt in it, the original fuel sock(filter) is a very fine filter and will clog after driving for a while. you can try blowing air into the line from behind your fuel pump back to the tank to blow it out, but do it carefully as you can blow the filter off the pickup tube . be sure to take your cap off tank when doing this so you dont balloon your tank. as well you can put a inline filter where your lengthof rubber line is coming out of your tank. Take the supply one section at a time and make sure there is no blockage, like from motor to your rear at the rubber line bowing through with compressed air, then with a new rubber line on blowing through the tank. I dont know the symptoms or history here but if it will idle and rev fine in park then starve on the highway, you more than likely have a blockage inthe tank. even with an old rubber line(which should be replaced of course anyway) if your vent and filter are ok at teh tank it should have 0 vacuum to pull the line shut...unless you have a 1000hp motor sucking through a stock 3/8 line...
This should cure it, old rubber lines usually deteriorate from the inside out, you may find a flap of rubber partially closing the fuel line, same applies to brake hoses. Tip if the line blocks on the highway carry a bicycle pump in your tool box with a ball or air bed nozzle, pipe off the carb and a couple of pumps is usually enough to get going again, don't ask how i know.
Sounds to me like somebody put either some real crappy fuel line on it or used vacuum line. All the old fuel lines I've dealt with get hard and crack and start sucking air but never get soft. In fact when they get so old you can break them by bending them.
How old is the tank? Soiunds too me like some trash is getting in the line and the fuel pump is collapsing the line. Had that happen to me on a 82 Mustang. Ended up being rust in the tank. Took tank out and had it cleaned problem went away!
Summit Racing has the braided stainless steel line for $4.00 a foot. I tried to save money by going 5 ft. of braided then switch to solid for the rest of the way. I spent more on steel tubing and brass fittings than it would have cost to just buy 10 feet of braided and be easier than all the leaking fittings. To cut the braided line, wrap a couple wraps of black tape around the line, then clamp a mini hose clamp as tight as you can. Now you can hacksaw without unraveling, and step over to the grinder and face it off smooth.
the tank is clean, you can look in the filler neck with a flashlight and see the seam in the bottom. i think its just suckin it shut. its almost 2 and a half feet long and i can pinch it shut with my fingers pretty easily. im going to replace it with some good ol 3/8 rubber fuel line and see what happens. ive got some 3/8 copper line i may try to work in. depends on how much rubber line i still have. ive got all day today to figure it out.
If you use steel line for the majority of your fuel line you should be okay. Copper line might be too soft. Save the flexible rubber line for short distance connections at the tank and to the fuel pump.
I do braided line everyday here in the shop - the steel braid will not prevent 'sucking' shut. The steel braid is for pressure, it'll suck shut as quick as any other rubber hose - in fact when used on drysump oiling there is a steel spring you can purchase that goes inside the hose to prevent collapse on suction sides of the pump. Some steel braid hose is laid on top of a teflon liner, typ used for extreme high pressure in brake systems, nitrous lines but the fittings are limited and hard to work with. Having said all that, i find it hard to believe a stock type fuel pump is sucking your stock fuel hose shut, put a 'mighty vac' on it and have a looksee - it will make a lot more vacuum than a fuel pump. I wouldn't buy anything yet as if you have a fuel supply problem then it is likely inside the tank or the pump is toast.
its a new stone stock mech fuel pump. and seriously, that line is super squshy like a silicone touniquet. ill post pics when i change it today. you can squish it shut like a straw. and its got prolly like 15 feet of steel line from the transfer to the pump. the tank is like super clean inside. when i drop the tank ill prolly clean off the sock on the sending unit. would it be dangerous to run it without the sock? i run a small glass inline filter just before the pump and the carb has a small paper element on the input. both are new. its a 66 impala wagon. i loaned the car to my brother in law in the fall and he ran cheap gas and no zzdp and cracked a piston in the original engine. so over the winter the only thing i had to put in it is a "HO" 305 out of a mid 80s trans am. its running a stock aluminum egr intake and a 500 cfm edelbrock. so its definatly not a "high fuel demand" engine
"i run a small glass inline filter just before the pump and the carb has a small paper element on the input. both are new."______ I would`nt run a filter on the suction side of the pump, Those glass filters are super fine and clog real quick, they may look clean but clog easy. Pull sender and check sock, probably the culprit, and use reg. fuel line. good luck
I replaced the entire fuel line in my '54 with new line and an inline fuel filter and kept the glass bowl for less than $30 bucks.
i replaced the line with that fuel injection line i was talking about. turns out its the same as the regular it just has stronger braiding in it. looks almost the same. it may have been the non vent locking cap. its history. i blew thru the new line to maybe clean off the sock in the tank and it wasnt venting very much, if at all. took it up the road, it seemed to do ok. but time will tell. ive got a big tin fuel filter here about the size of a pop can. im going to put in on the inby side of the pump. and elimitate the glass one.
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