Fuel line routing on 69 v.w.fuel pump.

[Buick35]

The fuel pump on my son's 69 v.w. has two tubes coming out of it ,one on top and one on the bottom and I'm wondering which on goes to the carbs and which one to the tank.Thanks.

[Rusty_OToole]

Lower is inlet, upper is outlet

[Rusty_OToole]

[Buick35]

Thanks,I think that's how I have it .Greg

[Buick35]

I just switched the lines around to the way they are supposed to be but still not pumping.I can see that it filled the plastic fuel filter but it not getting fuel to the carbs.I'm tiring the motor I've by hand with the plugs. out

[Rusty_OToole]

Try pouring about half a shot glass of gas down the carbs and starting it. If it fires, even for a minute, it will soon pump up the gas.

[Pfeil]

FYI while you're in there.

 On these old VW/Porsche engines.

 Check the pressed in tubes on the fuel pump and inlet to carburetor. Give them a good yank. I've had them pop out while driving. One time the output from the fuel pump popped out and doused the whole engine compartment. Lucky, the car didn't burn to the ground. Also check and make sure there is a rubber grommet in the engine tin where the fuel line comes in behind the engine is there. If not, the engine vibration will cause the fuel line to rub against the tin and cut the fuel line in half (right over the rear left side of the cylinder head) for a nice fire. 

Note if a fuel tube is loose on carburetor or fuel pump, just pull it out, put in a vise and slightly oblong it, bend it and scuff up the tube, then clean it and the carb or pump hole and epoxy it and tap it back in and let it dry and harden up. It won't come out again.

FYI fuel pressure is 2 1/2 psi

Edited May 25, 2023 by Pfeil (see edit history)

[Buick35]

I just switched the lines around to the way they are supposed to be but still not pumping.I can see that it filled the plastic fuel filter but it not getting fuel to the carbs.I'm tiring the motor I've by hand with the plugs. out

[Buick35]

Thanks,It's currently on an engine stand and it has a starter attached to it but I don't think the starter works,I put juice to it from my battery charger and it just sparked.I've got to get a good starter and try again.I pulled off the fuel pump and pumped it by hand and fuel started pumping out of the bottom port so I reinstalled it with that port going to the carbs.Is it possible that turning the engine by hand just isn't fast enough? Later on my son wants to go with an electric pump anyway.For now I just want to get it running.Greg

[Rusty_OToole]

Did you notice how much gas the pump pumped every time you pushed the lever? It will pump some fraction of that every time you turn the engine over once. So you may have to turn the engine over 40 times to pump up enough fuel to fill the carburetor bowls. When the engine is running it turns over that many times in 5 seconds.

 

If you want to turn the engine by hand go ahead, just know it will take a lot of turning to pump the carbs full.

[Rusty_OToole]

If it's not in a car and the starter doesn't work and you are not going to run it why do you care if the carbs are full of gas? It's better to leave it dry until you are ready to start it. Leaving gas sit in the carbs can cause corrosion and gum up the carbs as the gas evaporates.

[Rusty_OToole]

A battery charger won't do anything. Not enough juice to turn it over. You will need to connect a good battery with large enough cables.

[TOM H. S.]

I had a '69 bug back in the day and often had to install new fuel pumps regularly. I bought mine at Caldor and they lasted for awhile. Genuine VW pumps were expensive.

You may want to see if the fuel tank is rusty and leaking too. I flushed mine out with water and was able to repair the rusted through spots and soldered them up well, repainted and reinstalled, not a quick fix, but it worked. Steel fuel line also went through the center stick shift tube. Best Wishes.

 

[Frank DuVal]

13 hours ago, Buick35 said:

I just switched the lines around to the way they are supposed to be but still not pumping.I can see that it filled the plastic fuel filter but it not getting fuel to the carbs.I'm tiring the motor I've by hand with the plugs. out

 

8 hours ago, Buick35 said:

Thanks,It's currently on an engine stand

If the engine is on an engine stand, where is the fuel coming from? Lots of possibilities with a non-stock setup. And answers based on an engine in the car may not apply here.

 

[Buick35]

I've just been pouring a small amount in the line that goes to the tank.

[kuhner]

You say it is on an engine stand, was it rebuilt?
Make sure there the push rod is in the block.  Item 1 on the picture Rusty posted.

[m-mman]

3 hours ago, Buick35 said:

I've just been pouring a small amount in the line that goes to the tank.

To properly test a fuel pump the suction line should be submerged in fuel. 

A fuel pump is designed to move liquid only. It takes a few strokes to bleed out the air. If you are trying to just “pour” fuel in the suction side you will never get enough into it to demonstrate proper operation.