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fuel line questions

24K views 10 replies 5 participants last post by  Pinion head  
#1 ·
I have a 67 GTO and I am planning on putting a rochester carb back on it. My questions pertain to the fuel lines. I have read that if the fuel pump has two lines running into it from the gas tank then you will require the fuel filter that has the one inlet and the two outlet fitting on it. This is the one that sets on top of the manifold. So my fuel pump has two lines running into it. Currently it just has a rubber fuel line running from the pump to the carb inlet. So I guess I will need the special fuel filter. My main question is so one of the outlets goes to the carb but where does the second filter outlet go?? Where does it connect and what does it connect too>>
Does this require a special tube or hose?? Any pictures would be really helpful.
thanks in advance. Hope this message gets posted.
 
#2 ·
If you have a fuel pump with 2 lines, it generally means your car has a/c. The smaller second line runs back to your tank to help prevent vapor lock. You will only have one fuel line running from the pump to the carb. Here are photos of the sending unit at the tank, one before the new stainless tank was installed, and one with the new tank and sending unit. So to be clear, you do not need a filter with 2 outlets.

 
#3 ·
Thank you for the information but you did not quite answer my question. Yes my car does have factory a/c. Here is where I am confused. I have two fuel lines running into my fuel pump, I'm not talking about the fuel tank. Then from the fuel pump there is one line running into the carb.. Now this is a Elderbrock carb. not the factory Rochester. I am planning on putting a Rochester carb on the car. So from what I gather I will need the fuel filter, the one that sets on the intake manifold, which has the three spouts on it. One is for the fuel coming into it from the fuel pump then one goes to the carb and the big question is where does the third one go?? I know it is suppose to run back to the fuel tank but from the fuel filter where exactly does it connect?? Is this a rubber hose or a metal fuel line??
thank you in advance.
 
#4 ·
Hi, again. There is a fuel filter inside the carb. It is accessed by removing the fuel line at the carb. On my car there is a single fuel line from the pump to the carb. It is part metal and part rubber. The rubber goes from the pump to an inline filter (not shown). One line in and one line out. Then a rubber line to a metal right angle line into the carb. Doubt this is factory routing. In the photo you see the rubber line connecting to the metal line and the into the carb. The red circle indicates where the brass carb filter is located. I don't use one these as Rochcesters have a bad problem with that big nut getting stripped from too many removals. If this doesn't help get the idea across then let me know.
 
#5 ·
OK, this may help. A little research and I found a diagram from Chicago Muscle: 1967 LeMans/GTO Fuel Tank & Lines Check out the link and it also provides what the parts are, you just have to use your thumb wheel on your mouse to scroll through the part numbers.

I also found this on the forums which will help describe it: http://www.gtoforum.com/f50/67-gto-fuel-line-carb-hook-up-c-36544/

There is a "Search" feature in red the upper right hand corner of the page where you can plug in a few key words that might pull up the needed info as I found for you.

That should help. :thumbsup:
 

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#6 ·
Alan, my 66 lemans was an AC car and has the two lines from the sender. Just like Jim's photo. I put in all new tank lines etc. at the pump, my car has A 67 GTO fuel pump,one inlet one outlet for the large feed line. Then the standard two steel lines I bought new from inline tube as I recall run behind the alternator. My wix fuel filter is the three prong. Feed in from pump, on the outlet side there are two feeds, one direct to carb, the large one and the small feed returns to the small 1/4 line from the tank down near the fuel pump.

The return does not go to the pump on mine, just back to the tank. Mounting it on the intake as some did, makes it closer to the carb and gives better fuel cooling. It runs strong no pressure loss. The rubber connections are between the lines and pump, lines and filter then to carb.

The return line is not a vapor line, it returns unused liquid to the tank, the circulation keeps it cool. And it was put on AC cars along with larger radiators and fans etc because the condenser dumps so much heat in engine compartment.

You should use the three prong filter if you have the return line as the advantage of cool fuel prevents percolation and vapor lock and fuel boiling.

Easy hookup, the Pontiac house have a bracket that mounts to the thermostat housing that holds the three prong filter. The carb also has the sintered bronze filter in the carb body, but hey cleaner gas is cleaner carb. My pressure is good always. Runs great!
 
#7 ·
RS381 part number at year one will give you the steel fuel line set that runs the return from the three outlet filter mounted on the intake,...much better than mounted straight up behind the water pump. The bracket is easy to find...other vendors have that as well...

The lines have the proper bends to run behind alternator easily........

The little one is just a bend if you need it going to carb......
 
#10 ·
Alan, Here are some photos of my filter mounted on intake. Originally this car had the straight up mount like in the diagram..but I like this better so I bought the bracket and the lines that make up this on the intake mount. added a fuel gauge.

Also Pw, no misleading taken,..we are all just discussing and trying to help. this is confusing as they made it different ways in different years, some with a three portal fuel pump, some with a two portal.

Sometimes guys add the tank return and sender just to get better fuel cooling, they can keep their same fuel pump and add the filter. The wix filter number is 33041.

Also I would take note of bear's advice on fuel pressure depending on your st-up..He runs a beast and fuel demand can be high with some hot set ups , so good advice there......... Mine is no problem with it,..... just a cruiser...

You might see my new Holley street avenger 2bbl in the photo, just popped that on because my old Rochchester just gave out.

That Holley runs perfect air fuel mixture at all ranges. I have a wide-band O2 in each exhaust and can read it while diving

Perfect 13.8 to 13.9 at idle,...light throttle cruise is 14.1 -14.3,....power @ wot drops to 12, maybe 11.5....runs like a dream.

But my timing is curved right as well............... anyway.................good advice from all and good luck Alan.

(Also I prefer the oeitker clamps on all my rubber fuel lines....not heater hose screw clamps!:nerd:
 

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#11 ·
Inline Tube or FineLines can make the correct bent fuel line & the return line. I always use the std coated steel lines, as the stainless lines, don't have the correct finish for a high point restoration. Stainless lines can be beyond aggravating to seat on the flare, & have just had great experience with using the std steel lines. Am using standard steel lines on cars that will shown, run down a drag strip, & occasionally driven. Stainless lines...really dont have a use for. Would be different need' if I was up North, & say, my Cummins Dodge had a snowplow on the front & was being driven in the slush & salt, sure it could use stainless lines. Used to stock many of the prebent pump to fuel inlet lines from Benko. never stocked '67's, as vast majority of locals were doing their own thing with carbs & non stock fuel pumps.