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Hey all 71 supreme 5.7 2 barrel
Vin# 342671M1
Trying to order a fuel sending unit
when I bought the car it had a Fuel pump with three lines Coming off it.
1 to the carb 1 to the tank 1 was plugged.
recently I hooked up the one that was disconnected to what I though was the return line going back to the tank.
so I assumed I have a Return system
removed Tank to fix some leaking lines
i find I have a single line sender?
does this mean I have a return line system or not?
I attached a pic of the fuel pump the line that goes to the back of the car that I hooked the line up to and the fuel center coming out of the tank my question is do I put a single line back in Or am I missing the return does the return go directly to the tank because there is more than one line back here there’s three up above that must be some kind of vents? Single line on tank?
Line I hooked up from fuel tank Return?
Line from fuel pump
Last edited by JOHNNYOLDS442; July 25th, 2020 at 09:51 AM.
Off the top of my head i think you have the wrong fuel pump for your set up.
ithink what you hooked upto as the return is the charcoal canister vent.
you might be right!
should I disconnect? Because when I pulled the tank have single line. So where should the return line go to? Directly to the sender?
I am home right now if anyone can help out to figure this out and take pics etc..
car is jacked up tank is out etc..
its 10:10 am here in AZ
I would like to put the correct fuel pump and sender what ever I have to change.
Last edited by JOHNNYOLDS442; July 25th, 2020 at 10:12 AM.
when I bought the car it had a Fuel pump with three lines Coming off it.
Assuming the sending unit is original, and it looks it, I think the answer is simple. You have a single line system, and whoever installed that fuel pump put in the wrong one and just capped the unneeded return line.
According to rockauto, both two and three-line pumps are correct for your car, and my guess is that your car takes a two-line pump. Leave the one that's there in there with the extra line capped, or replace it with a correct, two-line pump.
Assuming the sending unit is original, and it looks it, I think the answer is simple. You have a single line system, and whoever installed that fuel pump put in the wrong one and just capped the unneeded return line.
According to rockauto, both two and three-line pumps are correct for your car, and my guess is that your car takes a two-line pump. Leave the one that's there in there with the extra line capped, or replace it with a correct, two-line pump.
So the line going from the side of the frame to the back of the car is the charcoal canister?line? I’m trying to figure out where exactly that runs to right now
I don’t want to assume my car originally came with a single line pump I kind of want to figure it out I appreciate your help I think it has a single line and you are correct the fuel pump is incorrect but what is that line that runs along the frame to the back of the car? Not a return line? I’ll tell you in a few more minutes where it goes I’m right by the rear axle now and seeing where it goes
This is the line from the front of the car that hooks up to the what I thought was the return line This is the actual fuel line
where do the three vent lines go behind the back seat?
Here is my Tank currently sitting in the driveway waiting to get hosed down.
3 vents 1 Fuel line no Returns???
I still wanna know what that other line from the front of the car goes to if not the return?
Also
Last edited by JOHNNYOLDS442; July 25th, 2020 at 10:55 AM.
Do you have the factory service manual for your car? There is LOTS of information in section 8 about fuel line routing.
Does your car have air-conditioning? If not, it came originally with a single-line sending unit and a two-line fuel pump. The carbon canister has two ports. One connects to the carburetor, and the other connects to the fuel tank to draw vapors off the tank. BUT, it does not connect directly to the tank. Rather, it connects to a standpipe assembly located behind the rear seat. There are four ports on this assembly. Three of them go to the three vent ports on the rear of the fuel tank while the fourth connects to the canister. There is no connection between the fuel pump and the canister.
Here are some relevant diagrams from the '71 chassis service manual.
Fuel tank. Note the three vent tubes on the side opposite the filler neck.
Information about the standpipe and about fuel return line usage. Yours is the "all others" category, assuming your car has no A/C.
Standpipe assembly. Used on all cars except station wagons.
Carbon canister hose routing, A-body, 2-bbl. Your situation is the lower one.
Fuel tank pipe and hose routing. Your situation is the top one.
Yes it has AC and I see the vent behind the seat I just posted a pic.
OK so that’s called the Emission pipe
Runs from the piece behind the backseat up to the canister that’s not there?
So I need a two line fuel pump and maybe just get a canister or That line off that goes to the vent behind the back seat?
Last edited by JOHNNYOLDS442; July 25th, 2020 at 11:12 AM.
If the car has A/C, then the three-line fuel pump is correct, and this is the appropriate figure from the manual.
If you don't have the service manual for your car, you should make getting one a high priority. There's lots of description that goes with these figures.
If the car has A/C, then the three-line fuel pump is correct, and this is the appropriate figure from the manual.
If you don't have the service manual for your car, you should make getting one a high priority. There's lots of description that goes with these figures.
Oh so that’s good news I have a single line
Sender? With a three line pump and that line goes to that standalone vent behind the seat that I just hooked up correct or not? I appreciate all your help and yes the manual would come in handy
If I'm looking at the Figure 8-19 I posted earlier correctly, it appears that you do need a two-line sending unit, and you connect the return line from the fuel pump to the second port on the sending unit.
Available for your car at rockauto.com for $34.99.
Off the top of my head i think you have the wrong fuel pump for your set up.
ithink what you hooked upto as the return is the charcoal canister vent.
^^^THIS. That is obviously a shiny new replacement pump. I remain amazed at why this is so difficult for people to comprehend. If the original pump had two lines, get a two line pump. If it had three, get a three line pump. This isn't rocket science, but we must get at least one question a month.
^^^THIS. That is obviously a shiny new replacement pump. I remain amazed at why this is so difficult for people to comprehend. If the original pump had two lines, get a two line pump. If it had three, get a three line pump. This isn't rocket science, but we must get at least one question a month.
It may be shiny and new but it was in the car before I purchased it so the discussion will continue it’s not basic if the car has been in a few hands??
Thanks for clearing that up Joe that’s no help whatsoever
It may be shiny and new but it was in the car before I purchased it so the discussion will continue it’s not basic if the car has been in a few hands??
I was referring to whoever installed that incorrect pump originally.
I was referring to whoever installed that incorrect pump originally.
I understand that but to come in the middle of a conversation after we’ve been going back-and-forth with discussion and pics and facts that what the car has in it just confuses the OP which happens to be me?
So what are you saying it is or is?
I was just confirming I had everything right and then you come in and make a comment and throws me off now I have to start all over again and ask you what you’re talking about?
While my tank sits in the driveway lol I ordered a two line Sender that is waiting for me at O’Reilly’s if the line from the front of the car off the fuel pump goes to the return vent on the fuel sender then what goes to the stand pipe behind the backseat?
gas tank is in the driveway waiting
Last edited by JOHNNYOLDS442; July 25th, 2020 at 12:49 PM.
OK, but use a little common sense. If the sender at the tank only has one line, the fuel pump should only have one inlet and one outlet, period. The fact that your pump has fuel return AND is relatively new should be a HUGE clue that it's not the right pump.
maybe thats True what goes on the fourth line coming out of the standpipe the back seat So what about the diagram with a car that has AC it has a three line pump and one line sender?
Last edited by JOHNNYOLDS442; July 25th, 2020 at 05:46 PM.
If I'm looking at the Figure 8-19 I posted earlier correctly, it appears that you do need a two-line sending unit, and you connect the return line from the fuel pump to the second port on the sending unit.
Available for your car at rockauto.com for $34.99.
OK so if I understand you correct I need a two line Sending unit.
Connect the extra line on the sender to the extre lone on the fuel pump? And the line that goes to the standpipe goes to the canister can I leave that disconnected? Because it’s capped at the carburetor?
My sending unit in the tank that must have been changed To a single correct?
Tank is back in Siphoning was fun! New sender Return one is so small 1/4? Gotta connect time a 5/16 metal line Going in! Almost in one strap done here New ground was too short what idiots Never been on Empty since I owned it
I only put a few gallons in from the gas cans the rest is in a 5 gallon bucket.
I didn’t feel like making a mess I will do that tomorrow.
when I took the car up the block you can see the gauge jump up a bit and back down.
I think it’s going to work fine.
Fill up tomorrow oh fill up for me is $10 haha thanks for the Help.
I also bought some 5/16 hose to go on the return line on the sender it’s 1/4 it should Squish down and the line itself is 5/16 that goes up to the fuel pump and then on the pump it’s 1/4 again I don’t know why they do that seems stupid engineering just make both ends 5/16.
the oil light is on because when I took that pic it wasn’t running I just turn the key on to watch the gauge.
Last edited by JOHNNYOLDS442; July 26th, 2020 at 08:11 PM.
July 25th, 2020, 09:10 AM
