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What would cause the fuel to drain back into the tank...

I d have never seen or sold a chevy fuel pump with more than 3 hose connections...mostly the ones with 3 hoses also had a bigger "can" and the three hoses were the inlet (usually a 3/8" barb fitting),and the other larger one goes to the carb,and the smaller 1/4" one is the return line to the tank--these pumps were used mostly on vehicles with A/C ,I have used them on others by simply plugging off the return line outlet with a hunk of hose with a bolt clamped in it with no ill effects many times........................................................................................................................................................................................................They also used a small metal can style fuel filter on some older GM's that had a third nipple for the return line,my '66 Buick Electra had that style...seen it used on some 70's trucks too...
 
I'm still a little puzzled.
Many times I have put a new or rebuilt carb on an engine. Each time it was totally dry. A few revolutions of the engine, and it was filled and the engine was running.

If you are having to prime the carb each morning, there is something wrong with your fuel flow. Even if it runs out each night, it should still crank up each morning.
Maybe just take a few more seconds.

The electric pump especally should have cured it.

My old 1966 F600 boom truck sits for weeks without being used. So, it takes a long time for it to prime the carb.
I added an carb rated electric fuel pump. Now I just turn on the key, wait a few seconds and its ready to go.

I am suspicious of that wet place you saw. I know we always harp on pics here, but a digital camera can be your friend too.
I have many time spotted problems in areas I could not get too. Just stuck a camera in there, and shot a few dozen pictures at different angles and with and without flash.
 
Well gentleman I took the time to change the hoses on top of the tank last night. Today I took her for a spin and I think we have found the problem with the stumbling. Not a single issue at stop signals or the highway? I'm sure I still need to clean the Carb but it runs 100% better. Thanks so much for the input and help here. Every single response could of been spot on! I learned a lot here and really appreciate the help! :woot:
 
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Metal Twister said:
Well gentleman I took the time to change the hoses on top of the tank last night. Today I took her for a spin and I think we have found the problem with the stumbling. Not a single issue at stop singles or the highway? Im sure I still need to clean the carb but it runs 100% better. Thanks so much for the input and help here. Every single response could of been spot on! I learned a lot here and really appreciate the help! :woot:
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Were they cracked or loose and leaking at the connections, or ... ?

-- A
 
Mine does this as well, but only on the slightest incline. Such a pain in the ass to do this in the morning. Especially if you do it, then it dies backing out of the driveway and you have to do it again. :doah:
 
dremu said:
Were they cracked or loose and leaking at the connections, or ... ?

-- A
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Old, and weather cracked and seeping... Had to cut them off the nozzles they were so hard and conformed to the shape of the nozzles. No real obvious holes or deep gaping cracks though. Just a bunch of shallow surface looking cracks were visible. I really didn't know if I had fixed the issue or not till I actually drove it this morning. Nothing looked really bad? But then again I'm betting they were the original hoses on there since 77. LOL
 
78SWB said:
Mine does this as well, but only on the slightest incline. Such a pain in the ass to do this in the morning. Especially if you do it, then it dies backing out of the driveway and you have to do it again. :doah:
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I cheated and cut in an access panel over the gas tank sender hole. Made my life much easier and I wont hesitate to keep on top of the hose upkeep from here on out. Might be the first place to look if your having similar issues. :dunno:

Id post up a few pics but I have a Jeep fsj Cherokee body on my K5 frame so it would be different. I also cut in a Burb filler door and spout a couple nights ago. I know you guys cant appreciate this but not having to baby sit a fuel nozzle for 10 minutes to put in 20$ worth of gas is just flat ass awesome! Throw the nozzle in and actually being able to us the nozzle lock is a dream come true!

CIMG0027.jpg
 
The float or needle/seat would have to be bad as well as the fuel pump for gas to drain back into the tank. If the carb has fuel when you shut the engine off and is dry when you go back, there is something wrong with the carb.
 
Blue85 said:
The float or needle/seat would have to be bad as well as the fuel pump for gas to drain back into the tank. If the carb has fuel when you shut the engine off and is dry when you go back, there is something wrong with the carb.
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Yeah, and even then, it should fill up quick when you started cranking.
That is why I kept looking at fuel delivery.

Usually the fuel pump. but in this case, it was probably sucking air. The reason the carb was dry the next morning, was because it did not get much gas in it at idle, and was almost dry when switched off the day before.

Looks like he fixed it when he replaced the lines.
 
Runs pretty good... still not just right on the lower power band though. I drove the wheels off of it yesterday and let it sit all night. This morning there was a little bit of cranking before it got gas and fired off. Thinking its time to rebuild the carb or at least give it a good cleaning. Went by O'reallys and talked to Jason. Found out the carb is a 85 to 89 vintage QJet. Ordered a rebuild kit for the carb so I will most likely go through it on a sober Friday night.
lmao.gif
After that I'm expecting perfection!?:dunno::waytogo:
 
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They leak. They are used to fill a casting hole. Rochester peened the carb body material over the plugs installed, those tend to leak. Epoxy is an easy fix.
 
There are two I am fairly certain are accessible simply by flipping the carb over, I'm not sure if the two additional require some disassembly or not. I think only one of the two pairs seals the float bowl, and I would bet those are the ones that require some disassembly.
 
dyeager535 said:
There are two I am fairly certain are accessible simply by flipping the carb over, I'm not sure if the two additional require some disassembly or not. I think only one of the two pairs seals the float bowl, and I would bet those are the ones that require some disassembly.
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Thanks, I'm guessing it will be fairly obvious when I get the thing off the engine and in my hands. I will post up a few pics when I get there to double check! Thanks again for the input guys! :bow:
 
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