I wouldn't trust the ratings on any fuel pump from the parts store. They are all made in China, probably by the same factory with a different label on the box. And the Chinese don't care about quality, just the money.

What I would do, is install a fuel regular, a fuel pressure gauge and "dial in" the correct amount of pressure. And I would not use the cheesy inline style with the rotary dial as they don't work. So you need to use the T (Holley) style in a deadhead configuration and reroute you fuel line as necessary.

That should solve your problem.

If you are still having problems such as boiling the fuel and empty fuel bowls from evaporation, then you need to do a return style of fuel system. This would include an electric fuel pump back by the tank, a return style of regulator and a return line back to the tank. Any other "solution" is half assed at best. And this is not a "race car" fuel system. It is almost a necessity with today's fuels and carburetors. Especially if your state has decided to follow California solutions for air quality control.

Oh, the 1/8" inch hole in a 3/8" fitting is an attempt to "regulate" the fuel pressure.

This seems a bit complicated for someone who just wants a functional stock fuel pump for a completely stock car, no?

I drove this car in 100°F temperatures this summer with no vapor lock problems, with completely original fuel lines.
I did replace my disintegrated original fuel sender with a later-model sender with a return barb, so I can add a return line at any time, if I want to.

I did buy a NORS AC pump and install it, and it puts out 5psi and appears to be working fine.

I do have an "empty float bowl" problem after leaving the car for a day, but I believe that is due to a leaky factory plug at the bottom of the float bowl (Carter BBS), under the inlet. I may try to epoxy it, but it's not my biggest problem right now.

Thanks anyway,

– Eric

My '74 Duster has been sitting around in various garages for 25 or so years. There is a nice shiny new fuel pump on the engine. I did not install this fuel pump. This fuel pump puts out 8psi and has caused all sorts of problems.

The you tube channel "Muscle Car Solutions" suggests the installation of a fuel regulator as an extra tuning aid, because you don't know how the carburetor will respond. Another you tube channel "Dead Dodge Garage" suggests that stock replacement pumps never needs a regulator. The you tube channel "318willrun" says that a stock fuel pump can propel his cars to 13 second quarter miles. All of these can't be true.

A stock \6 fuel pump should but out 19gph at 4.5 psi. This is good for about 145hp. How may replacement pumps actually do this any more? The replacement parts industry doesn't care. If the pump is "defective" they just replace it with a different part, which also may be "defective". But all of these parts have passed various manufacturing tests and are made in factories that pass various ISO standards.

It is up to you to protect yourself.

Agreed.

– Eric

For those following along, I posted the end (??????) of this story here as a separate thread.

– Eric

Let's add that to the already-thick file of evidence against current/recent shelf-stock Slant-6 fuel pumps being not fit for purpose.
Wait, wait…you're suggesting there's, like, wrong and contradictory and misleading and bogus advice to be found on the internet?

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I have seen it many times, Abe Lincoln has told me that everything on the internet is real. If you can't trust Honest Abe who can you trust?

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Too many people who were born on third base actually believe they've hit a triple.

I was the custodian of Kesteb's Duster before he bought it from my brother. I dug through my pictures of the car and I believe that shiny fuel pump was on the engine when we bought the car back in 2009(?). It sat in my garage for almost a decade, and we bought it from a board member who had it sitting out behind his apartment for a few years, so there is a good chance that fuel pump is 20 years old. Plenty of time for a diaphragm to dry out and fail.

Sorry Kesteb. My brothe rand I had that engine running a few times, but not very often. It always seemed to run well when we had it fired up but I think it only left my driveway under its own power once in ten years.

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Casually looking for a Clifford hyperpak intake for cheap.

Since I bought the car, It may have about 100 miles more on it. That fuel pump is nice and shiny though. To bad it puts out way more then 4.5 psi. Oh well, that what fuel pressure regulators are for.

You can always follow my YouTube channel and follow the reconstruction. YouTube is about 9 months behind reality.

…and we might also say something like yeah, it puts black smoke out the tailpipe, but that's what corks are for. Both answers are wrong.

The right answer is a fuel pump that meets the specifications for the application.

_________________
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Too many people who were born on third base actually believe they've hit a triple.

So what is the official specification? Fill a pint jar in under 30 seconds. I believe that is the trouble shooting procedure for the pump.

The 4.5 psi comes from NAPA, where they tend to display this stuff when buying parts. They also list 18gph as the flow rate, which would be consistent with 145 gross horsepower rating for the 225.

Sure it would be nice to buy the correct pump. But this stuff is made in China, probably in one factory and they just change the box when they ship them. Who knows what specification they are following when testing the pump in that nice shiny ISO certified factory. If if is fill a jar in 30 seconds, they don't have to care about pressure and flow ratings. Just filling the jar. Unfortunately the needle and seats of the carburetor does.

But then you have a life time warranty from the parts store and you can replace it as many times as you want on their dime. And everybody is happy, right, right?

These are the official specifications (from the 1973 Dodge Chassis Service Manual pp 14-62 and 14-67):

TESTING FUEL PUMP (On Vehicle)
If the fuel pump fails to supply fuel properly to the carburetor, the following tests should be made before removing the fuel pump from the vehicle.

Pressure Test
(1) Insert a "T" fitting in fuel line at carburetor, (Fig. 5).
(2) Connect a 6 inch piece of hose between "T" fitting and gauge C-3411. (The hose should not exceed 6 inches. A longer hose may collect fuel and
additional weight of fuel would be added to pressure of pump and result in an inaccurate reading.)
(3) Vent pump for a few seconds (this relieves air trapped in fuel chamber). If this is not done, pump will not operate at full capacity and low pressure reading will result.
(4) Connect a tachometer, then start engine and run at idle. The reading should be as shown in specifications ([3.5 - 5 psi]) and remain constant or return to zero slowly, when engine is stopped. An instant drop to zero indicates a leaky outlet valve. If pressure is too low a weak diaphragm main spring, or improper assembly of diaphragm may be the cause. If pressure is too high, main spring is too strong.


Vacuum Test
The vacuum test should be made with the fuel line disconnected from the carburetor. (This will allow the pump to operate at full capacity, which it must do to prime a dry carburetor.) The minimum reading should be at least 10 inches of vacuum at idle, with the fuel line disconnected at the carburetor.

Volume Test
The fuel pump should supply 1 quart of fuel in 1 minute or less at idle.

Inlet Valve Test
To test the inlet valve, connect a vacuum gauge on the inlet fitting while the line is disconnected.
(1) Start engine or turn over with starting motor.
(2) There should be a noticeable vacuum present, not alternated by blowback.
(3) If blowback is present, inlet valve is not seating properly and a new pump should be installed. If fuel pump does not perform to above test requirements, a new fuel pump should be installed.
1 gallon in 4 minutes = 15gal/hour. Pretty close.

Amusingly speculative.

See "official specification" above.

I know I've been happy every time I've changed a fuel pump.

Dan already provided excellent explanation and suggestions above. I won't repeat them.

- Eric

3 to 5 PSI.
That's a quick 'n' dirty, reasonably accurate test to check if the pump is working — that is, whether it can provide a decent volume of fuel in a reasonable amount of time. It tells nothing about the pressure.
Maybe. How do you figure? I'm not saying you're wrong or anything, I'm just not imagining the math. Show me?
And that's still entirely possible, just — as with so many parts for our old cars — not through the parts stores you'd patronize for parts for a recent car. You go on eBay and pick out one of the good kind. The large-body AC pumps usually aren't very costly, though there's a bit of age-related gamble involved. If you want to eliminate that gamble, you snag one of the bolt-together pumps, get a rebuild kit from Then and Now Automotive (making sure to specify a 3 to 5 PSI spring), and there you go.

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Too many people who were born on third base actually believe they've hit a triple.