1949 chrysler fuel pump question

[Jeff I indu]

A few days ago took my 49 chrysler royal out for a spin. After a few miles it sputtered and died like either out of gas or bad gas. Haven't driven it much lately so i suspected bad gas. Pulled the gas guage and siphoned the old gas out. The inside of the tank looked good but still won't start. Added fresh gas but can't get it to pull to the carburator. Starts easily with starter fluid. Pulled the supply line off the fuel pump and had my wife crank it over while feeling for vacuum from the fuel pump. I didn't feel any pull. Before I order a fuel pump rebuilt kit I was wondering if maybe the pump needed to be primed to pull gas from the tank. I did pull the bowl and cleaned it so it was empty while I checked for vacuum. Just not sure so thought I would ask

 

Jeff

[Doug&Deb]

The pump should pull without priming. If you can rebuild the pump I recommend that over replacing it. The new ones are not well made. It’s possible that the ethanol ruined the diaphragm. A good rebuild kit should have ethanol resistant parts and should last for a long time. 

[Ivan_B]

10 hours ago, Jeff I indu said:

Pulled the supply line off the fuel pump and had my wife crank it over while feeling for vacuum from the fuel pump.

I believe that this is usually done by removing the supply line off the carburetor (or taking the top off) and seeing if you get any fuel, while cranking ?

[Jeff I indu]

Thanks for the responses. A fuel pump rebuild kit is ordered. I pulled the supply line off the fuel pump to blow air back into the gas tank. There is no inline fuel filter that I could find. I don't know if the gas tank had a internal screen or not. I wanted to eliminate that possibility. The sediment bowl is the only form of filtration that I can find on my car. At this point I am sure my issue is the fuel pump

Jeff

[Sniper]

1 hour ago, Jeff I indu said:

Thanks for the responses. A fuel pump rebuild kit is ordered. I pulled the supply line off the fuel pump to blow air back into the gas tank. There is no inline fuel filter that I could find. I don't know if the gas tank had a internal screen or not. I wanted to eliminate that possibility. The sediment bowl is the only form of filtration that I can find on my car. At this point I am sure my issue is the fuel pump

Jeff

 

The stock pickup in the tank has an oilite insert that is the filter. 

[Jeff I indu]

I rebuilt my fuel pump as suggested by this forum. My issue now is that it is hard to start after sitting for a month or so. I have to crank the starter for a good 20 seconds until the gas seems to hit the carb and then it runs great and starts easily the rest of the day. I believe my issue has to do with the needle and seat allowing gas to bleed back past the fuel pump. But it also seems there should be enough gas left in the fuel bowl to start the engine until the fuel pressure builds back up. I am debating on rebuilding the carburator or possibly switching to a electric fuel pump. Or is it normal for a hard start after the car sits for a few months? It is a fluid drive car with a Carter ball and ball carburator that I believe is original

 

Jeff

[Dodgeb4ya]

If sitting for long periods of time....Crank the engine over a couple of times for 10-15 seconds. 

Leave to do something else for 10 minutes...come back, pump the gas pedal four or five times- start the engine.

Has worked for me for years with my MoPar flatheads.

 

 

 

[Tom Skinner]

It is no news: GMs like to eat starters and alternatores, Fords like to eat Transmissions, Chryslers Like to eat Fuel Pumps.

There you go Fifty Five years of Mechanical observation that can be scarcly refuted. I have owned GM's, Fords, and Chrysler Products for Fifty Five

Years and this is the Maxim or Regular situation I have experienced for Fifty Five Years, Why I have NO IDEA. From 1967 Pontiac Bonneville's from 1967 Ford Thunderbirds to 1948 or 1968 Chrysler Imperial Chrysler's the ***** Big Three have remained cemented to their Jackass Trade. Why in God's name couldn't the Engineeres have done any better than this? Now you know why Toyota, Nissan, and Hyudia ( Or the Other Dragon Vehicles) Have eaten our Lunch. We are probably One and Done because of this continual Stupidity. Europe is no better Raping Us with Autos while excepting none of ours in their market as well. BMW dump useless cars into our system that lose their values at an alarming Rate. Chrysler is ruined because nobody cared to fix it from Bob Gale to Daimler Benz and Dieter Zezhkie to Stalantis. we Screwed ourselves believing a System that is Broken. Now Chrysler's Great Grandson Thinks we should buy Chryser Back. Well put your money where your mouth is and BUY IT BACK! We Are So DONE!

Why can't American's just DO THE RIGHT THING!

 

[Dodgeb4ya]

Wow! All I can say.

[Plymouthy Adams]

double WOW.....never seen anything that would say the above would be anything close let alone exact......

[desoto1939]

21 hours ago, Jeff I indu said:

I rebuilt my fuel pump as suggested by this forum. My issue now is that it is hard to start after sitting for a month or so. I have to crank the starter for a good 20 seconds until the gas seems to hit the carb and then it runs great and starts easily the rest of the day. I believe my issue has to do with the needle and seat allowing gas to bleed back past the fuel pump. But it also seems there should be enough gas left in the fuel bowl to start the engine until the fuel pressure builds back up. I am debating on rebuilding the carburator or possibly switching to a electric fuel pump. Or is it normal for a hard start after the car sits for a few months? It is a fluid drive car with a Carter ball and ball carburator that I believe is original

 

Jeff

Jeff:  I have a 39 Desoto and I have installed an electric fuel pump back on the frame near the gas tank. Electric FP are a pusher type of pump and not a puller type like the mechanical FP on your car.  Yes, if your has not been run in a month and even sometime within a couple of days after currently running the car the fuel evaporates in the line upto the carb and then you will have to crank the engine to get the mechanical pump to draw enough fuel from the tank through the FP and up into the carb and fill the fuel bowl in the carb and then the engine will fire up.

 

So most of us MoPar owners have installed electric pumps to be used as a primer pump to get the fuel supply restarted and get the fuel flow moving into the Carb.  Also they can be used incase you get a vapor lock when the fuel line get so hot from the engine heat you then start the Electric FP and then gas then is pushed and the car will continue to run.

 

I have it setup so that I can only turn the Electric FP on via a toggle switch and this can only be done when the ignition switch is turned onto to start the car. So have set up an inertia switch to kill the pump if the car is involved in an accident. Some have also installed a push button switch to activate the flow so that when you release the pressure on the button the El pump then stops working.

 

The options of how you want to install and operate the El FP is your own personal choice, but would advise installing an EL FP as a backup unit.

 

Rich hartung

[Jeff I indu]

Thanks all for the comments

I did try Dodgeb4ya's idea last night night but it did not help. Actually killed the battery and had to charge it for a while. With a fresh charge it started after 6 or 7 seconds. This morning it started the same way after 5 or 6 seconds. So this afternoon I decided to disconnect the gas line at the carburator to see if it still had gas in it. It did not. Then took the brass fitting off the carbuator. I did not know the needle was right there. There was some type of small pieces of plastic on the tip of the needle and also on the seat inside the brass fitting. I cleaned both, put it back together and started it up and let it run a few minutes. Now I have to wait a week to see if the hard starting is fixed but I think it is. I have no idea where the plastic came from unless it was in the fuel pump when I installed it.

Jeff

20250609_161949.heic 20250609_161917.heic 20250609_162016.heic

[Jeff I indu]

 

20250609_161917.heic 20250609_161949.heic 20250609_162016.heic

[Jeff I indu]

Can't seem to get the pictures to open properly

Jeff

[Los_Control]

They are heic or apple files, they need to be converted to .jpg first

 

 

[Jeff I indu]

Got it.

Thanks

Jeff

[desoto1939]

could someone have used pipe thread or pipe tape on the threads were the needle valve was installed into the carb?  Just a thought. was there any other sediment in the bowl of the carb?

 

Even if this fixes your issue I would still really consider installing an electric 6 v fuel pump as a backup to the mechanical pump.

 

Rich Hartung

[Jeff I indu]

I didn't open the carb up. No tape on the fitting and the carb showed many years of not being cleaned. I did spray the throttle body with carb cleaner but that was it. I like the electric fuel pump idea but want to first see if the gas still bleeds backwards after sitting a week or so.

 

Jeff

[desoto1939]

3 hours ago, Jeff I indu said:

I didn't open the carb up. No tape on the fitting and the carb showed many years of not being cleaned. I did spray the throttle body with carb cleaner but that was it. I like the electric fuel pump idea but want to first see if the gas still bleeds backwards after sitting a week or so.

 

Jeff

Jeff your gas will still have a tendency to evaporate if the car is not being started on a regular pattern.  So this is why using an electric aux pump is so useful.  You prime the fuel system after sitting for awhile, gas is now in the fuel line and up to the mechanical FP and some gas is now in the line upto the carb. Much easier to start the car. less wear and tear on the engine and walls of the cylinders, no need to drain the battery and espcially no need to spray starter fluid into the carb that can wash the oil off of the cylinders.

 

Rich Hartung

[Sniper]

My 51's needle looked like that and the carb leaked gas when running.  Rebuilt the carb, no issues in thelast 4 years. 

 

[meadowbrook]

What style of electric fuel pump also allows fuel to be pulled through it when off?

[soth122003]

3 hours ago, meadowbrook said:

What style of electric fuel pump also allows fuel to be pulled through it when off?

Most of them. The EP being a pusher pump will usually allow a MP to pull fuel through them with ease, unless they are gunked up from stuff in the tank. Just get a 6v fuel pump. Since it is a DC motor polarity won't be an issue.

 

Joe Lee

[soth122003]

On 6/9/2025 at 4:57 PM, Jeff I indu said:

I like the electric fuel pump idea but want to first see if the gas still bleeds backwards after sitting a week or so.

Not posting this to snarky or sound condesending but after you finish running the engine and park it, the engine will heat soak under the hood and expand the fuel in the carb float bowl. This fuel dribbles into the throat and evaporates which will lessen the fuel level in the bowl, thus the float lowers a bit. After a week or so you also have normal evaporation because the carb is not air tight because of the idle and running circuits in the carb. This also lets the float come down a bit more, which in turn opens the needle and no longer maintains a vacuum so to speak on the fuel line and then gravity takes over and the fuel flows back down the line to the pump. Since the pump only actuates off the cam every 2nd rev of the engine, it takes a bit to refuel the line. Now with that said, there is usually enough fuel in the bowl to start the car. However these old beast can be cantankerous and give you a fit about starting every week. The electric prime pump will eliminate this and should give you a smooth start every time. Before I put the prime pump on mine it would take up to a minute to get mine started after a week or two and a minute of cranking at 15 to 20 seconds a pop does no favors for the battery. Hope this helps.

 

Joe Lee

[meadowbrook]

3 hours ago, soth122003 said:

Not posting this to snarky or sound condesending but after you finish running the engine and park it, the engine will heat soak under the hood and expand the fuel in the carb float bowl. This fuel dribbles into the throat and evaporates which will lessen the fuel level in the bowl, thus the float lowers a bit. After a week or so you also have normal evaporation because the carb is not air tight because of the idle and running circuits in the carb. This also lets the float come down a bit more, which in turn opens the needle and no longer maintains a vacuum so to speak on the fuel line and then gravity takes over and the fuel flows back down the line to the pump. Since the pump only actuates off the cam every 2nd rev of the engine, it takes a bit to refuel the line. Now with that said, there is usually enough fuel in the bowl to start the car. However these old beast can be cantankerous and give you a fit about starting every week. The electric prime pump will eliminate this and should give you a smooth start every time. Before I put the prime pump on mine it would take up to a minute to get mine started after a week or two and a minute of cranking at 15 to 20 seconds a pop does no favors for the battery. Hope this helps.

 

Joe Lee

What wasn’t snarky. Good explanation.