Fuel Pump Not Working

[Fourward]

Engine installed, starts momentarily with gas poured down the carb. I tried to run the car out of a container of gas into the fuel pump. Then I could adjust the distributor for better timing. There is no suction from the pump, no gas going into it. I have the line on the lowest hole on the pump. Seems like the correct inlet. The pump is firmly attached. New pump. Could it attach tightly and not have the arm under the eccentric on the cam? Why isn't it working?

[Gunslinger]

You could have the arm not installed properly.  It could be a bad pump altogether.  It could have a bad diaphragm...smell the dipstick and see if it has gasoline mixed with the oil.  If the diaphragm is torn it can dump gasoline right into the crankcase.  That's unlikely but it happened to me  when I was driving the '63 I once owned.  

[Fourward]

I'll see if there is any gas in there. I guess either way it comes off. Does the arm go UNDER the cam?

[mfg]

4 hours ago, Fourward said:

I'll see if there is any gas in there. I guess either way it comes off. Does the arm go UNDER the cam?

Yes, the arm is installed under the fuel pump eccentric, which is bolted to the front of the camshaft.

[wildfelr]

Myers stude in ohio has toe correct pump

Happy New Year to all the crew in Ohio...

[Zedman]

On 1/2/2024 at 9:05 AM, Gunslinger said:

You could have the arm not installed properly.  It could be a bad pump altogether.  It could have a bad diaphragm...smell the dipstick and see if it has gasoline mixed with the oil.  If the diaphragm is torn it can dump gasoline right into the crankcase.  That's unlikely but it happened to me  when I was driving the '63 I once owned.  

Filling the sump with Gasoline is very possible and happened to me. (very next day after an oil change 🥵) Car was parked nose-down in my sloping driveway just to expedite the problem. Diaphragm was fine, but I believe the non return valves were not up to snuff.

Edited January 3 by Zedman

[Fourward]

Yeah, I'm stumped. New pump. Took it out, put a borescope in there and saw the eccentric way at the top so the arm should go right in. It did, pump bolted on easily. Still doesn't work. I'm going to use my air pump for a tire and blow some air into the input hose. If it leaks at the pump there should be a rip in the diaphragm? Right? What else can I do?

[Gunslinger]

This is out of left field...but the fuel pickup in the gas tank could be clogged and not allowing fuel to pass.  Even then...there should be some suction at the pump.

Usually the simplest possibility is the most likely answer...a bad fuel pump.  The pump arm could be bent wrong.  Try another.  You could also install an electric fuel pump under the car inside the frame rails near the fuel tank and bypass the mechanical fuel pump altogether...just install a blocking plate over the fuel pump opening on the block.  That's a bit more involved...cost of the pump and pressurized hose and installation but it should fix the issue permanently.  

[silverstude]

If you changed out the mechanical pump and didn't have to fight fuel running out of the supply hose, then that would indicate the problem is likely not the pump.  

 

[Fourward]

Thanks for the replies. The gas tank is not in use. I am running gas out of a container near the front of the car.  I like that simple solution is probably the most likely. I only have to get the supplier to take back the pump. It is good to know that an electric pump can solve the problem no matter what.

[silverstude]

Electrics have their learning curve also

[Fourward]

Update. I took the pump off and tried to test it by moving the arm up and down with a hose in a jar of gas. It does seem to work! I think I am attaching it wrong. I tried a THIRD time and could feel the arm seating in a good place, but was not strong enough to hold it there and get a bolt started. So, an update when I get a helper. Thanks, all, for any input.

[Nelson]

I know the vendors are having trouble with the new pumps. The arms on many need to be bent to conform to the original. I wouldn’t doubt that is your problem. However, is the eccentric tight on the end of the cam? Sounds like it’s a fresh overhaul?

[Fourward]

Nelson, I didn't touch the cam when I rebuilt it. Unfortunately, I don't have the old fuel pump to compare.

[Dwight FitzSimons]

18 hours ago, Fourward said:

Update. I took the pump off and tried to test it by moving the arm up and down with a hose in a jar of gas. It does seem to work! I think I am attaching it wrong. I tried a THIRD time and could feel the arm seating in a good place, but was not strong enough to hold it there and get a bolt started. So, an update when I get a helper. Thanks, all, for any input.

I assume you have a 259 or 289 engine, not an R1 or R2?

Rotate the engine so the eccentric that drives the fuel pump is at its "low point."  That is, so the lobe is opposite to where it pushes the pump arm down.  Then, you'll be able to install the pump.

A lot of people have had trouble with the Airtex fuel pumps sold in the FLAPS stores, to the point where they consider them to be unusable.  An original Carter pump, rebuilt, is a better choice, OR a new pump from one of our vendors, such as Dave Thibeault or Phil Harris (high performance specialists), or SI or Stephen Allen's.

[Fourward]

Thanks Dwight. Got the pump from Bob Ziff, whom I trust.

 

[Fourward]

Thanks again, Dwight. I held the pump in there, I could feel the arm under the eccentric, had my wife bump the engine by turning the key, it became easy to push the pump flush and install a bolt. That shoulda been installed correctly. I'm not a 5 star mechanic, but, I have put 2 fuel pumps on old cars successfully. There has to be something wrong with the arm. I'm going to try and return the pump.

[A0136]

Top pump is the modified Mopar pump.

Bottom pump is an R2 pump.

What does your pump arm look like.  
 

[Leo B]

R2 https://www.nostalgicmotorcars.net/store/p113/Fuel_Pump%2C_1963-64_Studebaker_Avanti.html#/
 

R1 https://www.nostalgicmotorcars.net/store/p114/Fuel_Pump%2C_1963-64_Studebaker_Avanti.html#/

Edit: I just noticed that you solved the problem. I did not read all comments. 👍

Edited January 11 by Leo B

[Fourward]

Leo, no the problem wasn't solved. I put it on and it didn't work for the third time. The top pump looks just like mine.

UPDATE. I got a new pump, it looks exactly like the other one. BUT, as I took the other pump off, the spring that moves the arm popped out. The arm seemed very easy to pump in the first place. The new pump that I got seems very hard to move the arm. Good thing that spring did not come off in the cavity. Anyway, I put a borescope in there, observed that the eccentric was going around, stopped it where it would be easy to install the pump like Dwight said. Installed pump. I am going to test it tomorrow. Fingers crossed.

[Leo B]

13 hours ago, Fourward said:

Leo, no the problem wasn't solved. I put it on and it didn't work for the third time. The top pump looks just like mine.

UPDATE. I got a new pump, it looks exactly like the other one. BUT, as I took the other pump off, the spring that moves the arm popped out. The arm seemed very easy to pump in the first place. The new pump that I got seems very hard to move the arm. Good thing that spring did not come off in the cavity. Anyway, I put a borescope in there, observed that the eccentric was going around, stopped it where it would be easy to install the pump like Dwight said. Installed pump. I am going to test it tomorrow. Fingers crossed.

It should be stiff when you try to pump by hand. The main reason for the breakdown of pumps is a broken diaphragm. Another reason is a leak, allowing air to enter. The third reason is that the fuel lines are blocked.
I have also new pump (R2) and works well. Before installing the pump, check if the fuel line is open between the pump and the carburetor. Also check if the line is open in the carburetor as well. I'm assuming fuel gets to the pump without air. When you attach the connectors to the pump, use a pipe lock. I use Loctite 542 thread sealant for fine metal threads, especially for hydraulic pipes. Of course, you can also use other recommended thread seal.

Edit: When I repair mechanics, I first look at the whole solution and what factors affect the solution and thus the problem. I would approach it step by step. 1. does the pump get fuel? 2. is fuel coming out of the pump? 3. does fuel also enter the carburettor (into the floats)? 4. does the fuel transfer to the intake manifold? 5. possible leaks.

Edited January 12 by Leo B

[mfg]

Well said!

[Fourward]

Installed second new pump. Works! Must've been the spring in the other one that was bad. Looked at a lot of old conversations here and Studebaker site. It is hard to install them incorrectly, and, if you do, you'll know it.