32 Model 86 Fuel Issues

[32BuickVicky]

I have an original 32 Buick Model 86 Victoria and I'm having some fuel issues.  It died on me 3 times last night....like it choked out and wasn't getting fuel.  Below is a diagram of the setup of the fuel system on the car.  The tank is original and after sitting for a couple years during COVID, I got some rust in the fuel filter after driving it for 10 miles or so. Changed the filter and it's looked good the last 30 miles or so, but I think there's probably some rust in that old tank. Fuel pump is working as best I can tell when turned on with the switch.  The fuel filter is not full of fuel at any time.  At idle or under acceleration, the filter just stays mostly empty with a small spurt of fuel being sent in to it and then out toward the pressure gauge and carb. My fuel regulator has to be set on 2 to 2.5 psi in order to generate 1 (ish) psi at the pressure gauge.  The Marvel carb is leaking from the lower gasket - recently rebuilt by a local mechanic less than 75 miles ago (older gentleman that knows his 30's autos but unsure how good he is at carb rebuilds).

 

Questions:

1. Should I remove the tank and use one of the Por15 sealing systems to recoat?

2. Should my fuel filter be mostly full of fuel and should I put the filter before the regulator to ensure it is filling?

3. Should I get a higher quality Fuel Regulator, Pressure gauge or even fuel pump to ensure the system is accurate?

4. Isn't there a gentleman who does a lot of the Marvel carb rebuilds that folks have recommended here before?

Any other information or suggestions is appreciated.

[Matt Harwood]

Start with cleaning the tank. My '35 Lincoln struggled with all kinds of maladies, all of which were ultimately traced back to a gas tank full of trash. Fix that first and see what happens. I suspect that your pick-up is clogging, along with the regulator and filter. If there's rust in the filter that far forward, you can be sure there's A LOT of it in the tank.

 

Send the tank out to be professionally cleaned and sealed. Trying to do it yourself to save money only means you'll be doing it twice.

 

With the tank clean, then you can diagnose any other problems (the carb shouldn't be leaking, for instance).

[32BuickVicky]

53 minutes ago, Matt Harwood said:

Start with cleaning the tank. My '35 Lincoln struggled with all kinds of maladies, all of which were ultimately traced back to a gas tank full of trash. Fix that first and see what happens. I suspect that your pick-up is clogging, along with the regulator and filter. If there's rust in the filter that far forward, you can be sure there's A LOT of it in the tank.

 

Send the tank out to be professionally cleaned and sealed. Trying to do it yourself to save money only means you'll be doing it twice.

 

With the tank clean, then you can diagnose any other problems (the carb shouldn't be leaking, for instance).

Matt, how hard is tank removal and replacement?  I've never attempted that and may need to employ a local mechanic if it's a substantial job.  Also, what fuel pressure psi should I be expecting at the Marvel Carb?

Edited April 26, 2022 by 32BuickVicky (see edit history)

[Matt Harwood]

Fuel tank is easy to remove. Make sure it's empty so it's not heavy; there is probably a drain on the bottom of the tank somewhere. Otherwise, use the electric pump to pump it into another container.

 

Once the tank is empty, remove the straps holding it in place. On older cars like yours, there might be two or three, or maybe even some brackets on the sides. The manual probably has details on how to remove the tank, but it should not be difficult at all. A few fasteners and then lower it out of the chassis with a jack or even by hand if you've got a helper. Easy!

 

I would say 1-2 PSI would be the most you should have at the carburetor. Does your car still have a mechanical fuel pump? I would try to put it back to stock if possible. If not, the electric pump needs to be regulated properly. I will admit that I ran my 1929 Cadillac on an electric fuel pump for a decade, but it ran right and was properly dialed-in. If you're using one of those disc-type regulators from Pep Boys, throw it in the trash and buy an expensive one from Summit racing. What you want is this:

 

https://www.summitracing.com/parts/aei-13222

Precise fuel pressure is critical on those Marvel carburetors. It really matters. Plus you can install your gauge at the regulator and have a much better idea of what kind of pressure it's putting out. Fine-tuning here can make a big difference in driveability.

[Robert Engle]

Tank removal is not too difficult.  3 items to deal with, wiring to gas gauge, fuel line, and two bottom straps.  Original fuel line was metal going from the gas gauge sending unit to a fitting on the right rear frame rail.  a floor jack and block of wood to support the tank as you remove the two bolts holding the straps to the tank. I'm not sure on the 80 series, but you might check under trunk mat to see if there is a plate you can remove to get to the wires and fuel line.  If not, just lower the tank enough to get to the lines and wiring.  If you plan to continue to use the electric pump, I would suggest moving it to the rear as close to the tank as you can get.  They work better as a pressure pump than a suction pump.  Make sure you use a high quality electric pump and regulator.  Cheap ones are never reliable in performance.  With the tank out blow out the line from the fuel pump to the gas tank. 

 

The Marvels work best at about 2psi.  They are not too difficult to repair once you understand them.  Get in touch with Mario.  He has done extensive research on Marvels and setting them up.  

 

Bob Engle

[Dave39MD]

If yours has the King Seely fuel gauge I would remove the little tube before lowering. 

 

Dave

[Grimy]

As to carb leaks upon shutdown, remember that with updraft carbs like yours, at shutdown the fuel vapor in the intake manifold condenses back to liquid and gravity takes it back to the carb.  If the carb's bowl is full, the excess will leak out.  Don't sweat the first three minutes of leaking after shutdown, but if longer than that you have a problem.

[32BuickVicky]

2 hours ago, Matt Harwood said:

Fuel tank is easy to remove. Make sure it's empty so it's not heavy; there is probably a drain on the bottom of the tank somewhere. Otherwise, use the electric pump to pump it into another container.

 

Once the tank is empty, remove the straps holding it in place. On older cars like yours, there might be two or three, or maybe even some brackets on the sides. The manual probably has details on how to remove the tank, but it should not be difficult at all. A few fasteners and then lower it out of the chassis with a jack or even by hand if you've got a helper. Easy!

 

I would say 1-2 PSI would be the most you should have at the carburetor. Does your car still have a mechanical fuel pump? I would try to put it back to stock if possible. If not, the electric pump needs to be regulated properly. I will admit that I ran my 1929 Cadillac on an electric fuel pump for a decade, but it ran right and was properly dialed-in. If you're using one of those disc-type regulators from Pep Boys, throw it in the trash and buy an expensive one from Summit racing. What you want is this:

 

https://www.summitracing.com/parts/aei-13222

Precise fuel pressure is critical on those Marvel carburetors. It really matters. Plus you can install your gauge at the regulator and have a much better idea of what kind of pressure it's putting out. Fine-tuning here can make a big difference in driveability.

I can't use the mechanical fuel pump because I can't find a push rod replacement.  As I understood from Mac Blair, the rods are not only year specific but model specific and finding a rod for mine is impossible. 

[32BuickVicky]

2 hours ago, Robert Engle said:

Tank removal is not too difficult.  3 items to deal with, wiring to gas gauge, fuel line, and two bottom straps.  Original fuel line was metal going from the gas gauge sending unit to a fitting on the right rear frame rail.  a floor jack and block of wood to support the tank as you remove the two bolts holding the straps to the tank. I'm not sure on the 80 series, but you might check under trunk mat to see if there is a plate you can remove to get to the wires and fuel line.  If not, just lower the tank enough to get to the lines and wiring.  If you plan to continue to use the electric pump, I would suggest moving it to the rear as close to the tank as you can get.  They work better as a pressure pump than a suction pump.  Make sure you use a high quality electric pump and regulator.  Cheap ones are never reliable in performance.  With the tank out blow out the line from the fuel pump to the gas tank. 

 

The Marvels work best at about 2psi.  They are not too difficult to repair once you understand them.  Get in touch with Mario.  He has done extensive research on Marvels and setting them up.  

 

Bob Engle

My gas gauge is not functional.  If I'm dropping the tank, maybe it's time to address that as well. Any idea on what kind of sending unit I would need to get it functional again?

[32BuickVicky]

So, an update and another question. I took off the entire fuel system, had the tank renu'd, new fuel pump mounted back near the tank, new aeromotive fuel pressure regulator as recommended above (set at about 1.5 psi). Had the Marvel carb bottom sanded down to fit flush and put everything back together. Took a while to get it to idle on it's own but when it does, I'm getting fuel leaking out from the top of the carb around the top gasket.  Makes me wonder if the needle and seat are bad. We are going to take the top off the carb when we start it next time and see what happens with the fuel level, float, etc. The carb has been rebuilt.  Any place to get replacement needle and seat?

Edited May 21, 2022 by 32BuickVicky (see edit history)

[tcslr]

Before you replace needle and seat, make sure the float is properly adjusted. It should be slightly below the elevation of the idle jets - scrib a line in the bowl that reflects the idle jet height. 
 

good rebuild kits have new needle and seat. Mr Blair has them. 
 

 

[32BuickVicky]

2 minutes ago, tcslr said:

Before you replace needle and seat, make sure the float is properly adjusted. It should be slightly below the elevation of the idle jets - scrib a line in the bowl that reflects the idle jet height. 
 

good rebuild kits have new needle and seat. Mr Blair has them. 
 

 

Unfortunately, Mr. Blair isn't very reachable these days.  Hopefully someone will have another source for rebuild kits. 

[32buick67]

PM sent...

[tcslr]

Carbking has kits though I don’t know if his have the needle and seat. 
 

 

[carbking]

20 hours ago, tcslr said:

Carbking has kits though I don’t know if his have the needle and seat. 

 

 

They do.

 

Jon

Edited May 21, 2022 by carbking (see edit history)

[carbking]

Before throwing rocks at your needle and seat, try a fuel pressure gauge right at the carburetor.

 

The regulator shown in your diagram is not known for its accuracy. Replacing a good needle and seat with another good needle and seat is simply expensive and frustrating......................................test first!

 

Jon.

[Bloo]

1 hour ago, carbking said:

The regulator shown in your diagram is not known for its accuracy.

You put that so diplomatically.

 

[carbking]

11 hours ago, Bloo said:

You put that so diplomatically.

 

 

Old definition of tact, by example:

 

No tact: "that lady's face would stop a clock"

Tact: "Madam, when I look at you, time stands still"

[BuickTom87]

Did you ever figure out the issue , or. Remedy to fix it