Any tricks for finding a leak in fuel line ?

-
Okay now I’m pretty confused , I temporarily replaced the rubber connections with some clear plastic hose just to see where the bubbles are coming from and at first no bubbles came up so I thought I was good. I took it for a drive and it sounded a lot better when I gave it some gas , but after a bit longer than before it started bubbling and hesitating and guess what, the bubbles were coming from the tank so I siphoned most of the gas out and took the sending unit out to check the pickup line for any rust or damage but the thing is SHINY brand new … I think my tanks pretty big and I was wondering if there’s only like 5 gallons in the tank would it not fully submerge the pickup line resulting in that bubbling ?
 
Diego53 said:
Okay now I’m pretty confused , I temporarily replaced the rubber connections with some clear plastic hose just to see where the bubbles are coming from and at first no bubbles came up so I thought I was good. I took it for a drive and it sounded a lot better when I gave it some gas , but after a bit longer than before it started bubbling and hesitating and guess what, the bubbles were coming from the tank so I siphoned most of the gas out and took the sending unit out to check the pickup line for any rust or damage but the thing is SHINY brand new … I think my tanks pretty big and I was wondering if there’s only like 5 gallons in the tank would it not fully submerge the pickup line resulting in that bubbling ?
Click to expand...


I would think that if the tank is the original and you are using an original pick-up, this shouldn't happen as it would have been a problem since the car was new. If you can, take the sending unit back out and plug the input end of the pick up tube . Submerge the unit in a bucket of water and blow air through the output end of the tube . If there is a leak, you should see bubbles in the water.
I'm thinking it may be leaking where the tube going into the tank is soldered to the piece that holds the sending unit to the tank.
 
AAndrews said:
I would think that if the tank is the original and you are using an original pick-up, this shouldn't happen as it would have been a problem since the car was new. If you can, take the sending unit back out and plug the input end of the pick up tube . Submerge the unit in a bucket of water and blow air through the output end of the tube . If there is a leak, you should see bubbles in the water.
I'm thinking it may be leaking where the tube going into the tank is soldered to the piece that holds the sending unit to the tank.
Click to expand...
Thanks Ill give that a try , but it is not the original tank and also one more thing: if that piece is not soldered correctly how would that make the pickup tube leak? If the tube is one solid piece and is just held in place by that connection why would the tube itself leak ? Maybe I’m misunderstanding you. Thanks
 
Diego53 said:
Thanks Ill give that a try , but it is not the original tank and also one more thing: if that piece is not soldered correctly how would that make the pickup tube leak? If the tube is one solid piece and is just held in place by that connection why would the tube itself leak ? Maybe I’m misunderstanding you. Thanks
Click to expand...

Just a guess on my part but if the tube was punctured or worn through at that location by movement over the years it would not be readily apparent in that location. You seemed to have covered everything else so this is something I thought might be worth a try.
 
Ok so I’m gonna check that pickup but I ran a bottle of gas taped to the grille going straight to pump and it worked fine no stalling no nothing ……. I am just gonna be so so confused if the pickup isn’t damaged because I am so sure the line isn’t leaking from any of the connections ….. we’ll see about the pickup I guess lol
 
Diego53 said:
Ok so I’m gonna check that pickup but I ran a bottle of gas taped to the grille going straight to pump and it worked fine no stalling no nothing ……. I am just gonna be so so confused if the pickup isn’t damaged because I am so sure the line isn’t leaking from any of the connections ….. we’ll see about the pickup I guess lol
Click to expand...


Cool! Running the engine off an alternate fuel source should eliminate carb/fuel pump and fuel filter as a problem area . Now you just eliminate the line from the pump to the tank , and then , the sending unit and pickup. I'd run a temporary rubber line to the sending unit from the fuel pump next. Just because you didn't see anything visual doesn't mean there isn't a problem. That would eliminate the steel fuel line . If you still have the problem, then you know its at the tank.
 
Rubber hoses !!!!! Especially the one going into the tank! Fill gas tank FULL to make sure pickup and line are covered. A cracked line will leak gas on floor since it’s the lowest place on car.
 
Okay thanks guys I appreciate how helpful everyone is here , I’ll get some rubber hose when I get my paycheck and see what happens
 
I fixed it !! You’ll never guess what was going on , so first I bought a fuel filter and some nice fuel injection rated hose clamps and about 7 gallons of gas. I took the sending unit out just to inspect it one more time and guess what I discovered … the sock filter on the end of the pickup was literally sucking down onto the end of the tube because the top and bottom of it were plastic and the sides are mesh ….. I cannot believe that someone would put this on their car and not think twice. With the sock pulled a teeny bit off of the pickup it works just fine but I sucked through it simulating a flow of fuel and it slips right back almost completely stopping any fuel flow . I removed that put the sender back in and I put a clear fuel filter right at the tank and started it up , not a single stall or hesitation and I drove probably 6 times farther then any other test drive so far , only thing is it has kind of a hard start when it’s warm and also I need to turn the idle down because it’s getting WAY more fuel then it’s used to.


Thank you FABO for all the ideas and conversation it helped me so much throughout the process and I really appreciate it u guys are awesome , now I know to check the parts that aren’t broken for crappy design haha
 
we used too use smoke for the evap system leak checker in the dealership...I suppose you could fire up a cigar and fill the tank and lines with smoke...no,dont do it LOL!
 
But where were the bubbles coming from?
 
Gearfinger said:
Post #42 and #44...
Click to expand...
You were right dude, but whenever I looked at the sender I blew through it and it was flowing great and it looked to be in really good condition, it was the design of the sock filter that was stopping everything up when it was under vacuum. I’ll post a pic of it
 
image.jpg
that’s the side where the end of the pickup tube would be , you can see it’s a perfect little end cap to stop up any fuel flow when it’s under vacuum.. just sucks right on to the end..
 
You must log in or register to reply here.
-

Back
Top