Fuel pump question....

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MAPS

MAPS

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Hello Fellow Mopar Champions...
Unfortunately this yr has been real bad for me physically speaking. Spinal Stenosis & will be needing surgery in the very near future, will know this Wed when I go back to see the neurosurgeon.
He is a Good AND LONG-TIME friend of mine and we tried everything to see if we could avoid surgery for as long as possible, tried physio (joke at this point) had an epidural steroid shot that they go thru the spine watching on a monitor (as I watched also) Although the " socialised medical system" that everyone thinks is so great in Canada does not cover the shot (500 dollars) even the private insurance I have did not cover it but I tried, anything for a small relief of the pain from the nerve touching the discs... Anyways the reason of my writing tonight is that it's time to take out the cars and I know that's the only thing that actually makes me feel somewhat better. I've just stopped worrying and praying for the best but looking out for the worst as well.

What I need to know is, I have a six pack on my small block and it's become a bothersome starting IT.
Example, if it's sat for a day or 2 trying to get fuel to the car's carb to start is upsetting.
I wanted to know can you place an electric fuel pump as in I picked up a real nice one Magnafuel that I believe I will also need to change the fuel line as well but can I also keep the stock pump also ?
I would use the electric one maybe with a switch that when I'm about to start the car I'll turn it on for a few seconds and then when the carb is full I can turn it over and she will start.

Trying now turning it over sounds like it's saying, " leave me alone lone lone....." Stop and start again having the stock fuel pump trying to bring the gas up to all the carbs (but mostly the middle carb, even though they all idle on the gas that's come up to start) I just feel that this fuel pump problem is solvable with an fuel pump but will I need to remove the stock pump, meaning I will have to listen to the fuel pump all the time the car is running....
Or the "leave me alone lone lone" pump until it finally fills up to start.
Thank you experts of the MOPAR WORLD.
MAPS
 
I'm pretty sure there are Pass-Thru style Electric Pumps that would let you Prime your lines and then leave off as you drive.
but for Starting, I have a little Carter Bbd with a Vent on the top. When it's been sitting I just give a squirt of Fuel into the vent to fill the Floatbowl.
It fires right up and runs for long enough to build pressure. Are you physically able to pop the Hood everytime and shoot some gas in there?
The 10% Ethanol stuff dries up pretty fast these day's. My carb is empty every weekend

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MAPS said:
Hello Fellow Mopar Champions...
Unfortunately this yr has been real bad for me physically speaking. Spinal Stenosis & will be needing surgery in the very near future, will know this Wed when I go back to see the neurosurgeon.
He is a Good AND LONG-TIME friend of mine and we tried everything to see if we could avoid surgery for as long as possible, tried physio (joke at this point) had an epidural steroid shot that they go thru the spine watching on a monitor (as I watched also) Although the " socialised medical system" that everyone thinks is so great in Canada does not cover the shot (500 dollars) even the private insurance I have did not cover it but I tried, anything for a small relief of the pain from the nerve touching the discs... Anyways the reason of my writing tonight is that it's time to take out the cars and I know that's the only thing that actually makes me feel somewhat better. I've just stopped worrying and praying for the best but looking out for the worst as well.

What I need to know is, I have a six pack on my small block and it's become a bothersome starting IT.
Example, if it's sat for a day or 2 trying to get fuel to the car's carb to start is upsetting.
I wanted to know can you place an electric fuel pump as in I picked up a real nice one Magnafuel that I believe I will also need to change the fuel line as well but can I also keep the stock pump also ?
I would use the electric one maybe with a switch that when I'm about to start the car I'll turn it on for a few seconds and then when the carb is full I can turn it over and she will start.

Trying now turning it over sounds like it's saying, " leave me alone lone lone....." Stop and start again having the stock fuel pump trying to bring the gas up to all the carbs (but mostly the middle carb, even though they all idle on the gas that's come up to start) I just feel that this fuel pump problem is solvable with an fuel pump but will I need to remove the stock pump, meaning I will have to listen to the fuel pump all the time the car is running....
Or the "leave me alone lone lone" pump until it finally fills up to start.
Thank you experts of the MOPAR WORLD.
MAPS
Click to expand...


You have some options.

One is get a small bottle with a small squirt top on it. Like a plastic mustard bottle or something. Kinda like what you’d see in a restaurant.

Put some fuel in it and when the bowls are dry or low on fuel from sitting you can squirt some fuel directly into the float bowl with that bottle. You can see how much went in there by pulling the sight plug or just watching how much is gone from the bottle. Then crack it off.

Of course, you have to pull the air cleaner to do that so there is that.

You can use an electric pump over the mechanical pump. It’s been so long since I’ve been inside of a mechanical pump that I can’t remember if you can force fuel through the pump and up to the carb of the pump isn’t in pump mode. In other words the pump lever would have to be on the nose of the eccentric.

Now that I thing about it...the electric pump won’t push fuel past the mechanical pump at any time.

If you are going to the trouble of the electric pump, you might as well get rid of the mechanical pump all together. It’s just in the way.

And if you do that, make damn sure you wire in a low oil pressure cut off switch in the system so the pump won’t come on until there is 8 or 12 pounds of oil pressure. That way, if you get in a crash or something and the engine gets killed the pump will shut off. Of you don’t have that wired into the system and you do have an issue the pump won’t shut off and it will keep pumping fuel. That’s a good way to get a nice little bon fire going with your car supplying most of the fuel.

Of course, if you go that route with the electric pump and the low oil pressure cut off switch, you will need to install a bypass switch so when the car has been sitting and you need to fill the bowls you can bypass the low oil pressure cut off switch.

I use a small push button switch in line with the low oil pressure switch. I use a push button rather than a toggle switch because you can forget and leave the toggle switch on and bypass the safety feature of the cutoff switch.

You have a switched 12 volt source to one side of the switch and run the other side out to the low oil pressure switch.

Then when you need to fill the bowls you put the key in the RUN position, hit your push button switch and fill the bowls. Once you let go of the push button switch you can start the car and the fuel pump will come on as soon as you get oil pressure.

I’m not a fan of fires so that simple little safety switch is cheap insurance.
 
Next time the car has sat for a week, have some one press the accelerator down a few times and you (or with your back) someone else look down the carb to see if the accelerator pump is pumping fuel into the carb if it is, then the carb is not dry.

My stock 67 dart 273 2bbl will start on 1 to 2 pumps and on the first try if I drove it yesterday. Last week is another thing. 2 pumps crank crank crank, 2 pumps crank crank crank and it will usually start. If not it will on the 3rd cranking.

That is in all weather, 25 deg cold dry garage in the winter or 80 deg dry garage in the summer.

I think we are spoiled by our new cars and FI, 2 seconds of cranking and it starts.

What I suspect is happening...

When you drive the car and shut it off, air fuel mixture remained in the intake. It is revativily sealed off from the atmosphere.

Then in a day or two it all has evaporated. And the only way to get the engine to start is to get air fuel mixture back into the intake.

When you pump the pedal you introduce raw file into the manifold, but no air. When you crank the engine the moving air helps to pick up some of the fuel and move it to the cylinder. But with the throttle blades and choke closed very little air is moving.

I recall reading somewhere that the best way to start the cars is to keep the throttle part way open while cranking. But I can't find the reference right now, might be in the glove box owners manual.

I have checked my own car for accelerator pedal shots and after a week I am still good.

Some theorize that the fuel is some how syphoning back to the tank and out of the carb, can't happen, fuel inlet is above the fuel level in the bowel.

If you suspect your fuel pump is a problem. SAFELY test it by collecting fuel in a bucket over time. disable the ignition and crank for 20 seconds and measure how much fuel you collect.

Unless your pump has an issue I think you will be surprised. 3 carb bowls empty is maybe 4 cups of fuel ( just a wild *** guess) I bet you get that in 4 to 5 seconds of cranking.
 
You can pump through a mechanical pump, no problem- the only restriction in a mechanical pump is to the direction of flow. The issue is the style of electric pump you use- whether it will allow the mechanical pump to "draw" through the electric pump when it's not being used. Diaphragm pumps should work, roller/rotary pumps may not.
For this, you don't need a big expensive pump, either; since it's just being used to "prime" the engine, not "feed" it. I have used the little cheapie $30 dollar electric pumps from the Ag supply store, just make sure the one you get has adequately sized ports- I have seen small 1/4" sized ones that are a no-go.
But before you do all this, confirm (as Dana67Dart said) that your fuel bowls are actually drying out. Early carbs with direct-to-atmosphere bowl vents are much more prone to this than later carbs with mechanical or electronically controlled vents, or sealed systems (think charcoal cannisters).
 
Ditto the previous question. Are you sure your Holley center hung float bowl is emptying in just a couple days without it leaking and leaving some evidence?
I think I'd run it a while, park it, pull the air cleaner off, pull the sight plug, and verify the bowl is full.
The next time I go to start it, I would hold the choke open and work the carb pump arm by hand, watching for the pump shot of fuel from the nozzle.

I've had a gummed-up valve hang on me, slowing the fuel shot considerably to none at all......

upload_2022-5-3_10-31-2.png
 
Professor Fate said:
You can pump through a mechanical pump, no problem- the only restriction in a mechanical pump is to the direction of flow. The issue is the style of electric pump you use- whether it will allow the mechanical pump to "draw" through the electric pump when it's not being used. Diaphragm pumps should work, roller/rotary pumps may not.
For this, you don't need a big expensive pump, either; since it's just being used to "prime" the engine, not "feed" it. I have used the little cheapie $30 dollar electric pumps from the Ag supply store, just make sure the one you get has adequately sized ports- I have seen small 1/4" sized ones that are a no-go.
But before you do all this, confirm (as Dana67Dart said) that your fuel bowls are actually drying out. Early carbs with direct-to-atmosphere bowl vents are much more prone to this than later carbs with mechanical or electronically controlled vents, or sealed systems (think charcoal cannisters).
Click to expand...


So if the engine isn’t turning and the pump arm is on the back side of eccentric can the electric pump still push fuel past the mechanical pump?
 
Rat Bastid said:
So if the engine isn’t turning and the pump arm is on the back side of eccentric can the electric pump still push fuel past the mechanical pump?
Click to expand...
Normally, with a mechanical diaphragm pump, yes.
A mechanical pump uses two spring loaded (poppet?) valves, one for the inlet and one for the outlet. Suction from the diaphragm draws fuel into the pump, then the valve closes. On the opposite stroke of the diaphragm, pressure forces fuel through the outlet valve, after which it closes. Both springs are only lightly loaded, since they are easily actuated by the 5-6# of pressure a mechanical pump creates.
Pressure from an electric pump ahead of the mechanical easily opens each of those valves (on the inlet, downstream pressure acts the same as internal suction), creating a flow-through.
For momentary "priming" use, a regulator on the electric pump should not be necessary, as most of the electrics I mentioned are pretty low pressure to begin with.
The issue, as I mentioned before, is whether the electric is a type that will allow "draw through" by the mechanical pump (in much the same manner as described above) during normal operation.
Easy test: Blow (or use low-pressure compressed air) into the inlet of the electric pump- if it flows air, it will work. If not, it won't.
 
Facet pump #40288 - the people at the company told me that a mechanical pump would draw fuel through this pump . I haven’t tried it as I use it for a different application. I do know that it isn’t the quietest thing.
Yote
 
I don't know if I mentioned that the engine is a small block, six pack it's a real nuisance if I have to take off the air cleaner, check the middle carb and the outside carbs don't have an accelerator pump they do have had running thru them but nothing to see befits the engine starts running.
I think I'm just going to go with a straight electric fuel pump and avoid any other issues. I just didn't want to be hearing the pump running all the time () but there could be worse things (to hear)
Only thing is I've been told I will need to change the fuel line from 3/8th to 5/16 or thru other way around so that extra money for nothing when I already have a brand new fuel line placed when the car was completely redone a couple of yrs ago.
Thanks guys, you truly know your shyt and this is why I just stick with this board. Period.
 
MAPS said:
I don't know if I mentioned that the engine is a small block, six pack it's a real nuisance
Click to expand...
So to avoid the nuisance to check 1 time if your fuel bowls are really dry you are going to go through the nuisance of adding an electric fuel pump which may OR may not save your issue.

Ok! your car your choice.
 
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Dana67Dart said:
So to avoid the nuisance to check 1 time if your fuel bowls are really dry you are going to go through the nuisance of adding an electric fuel pump which may OR may not save your issue.

Ok! your car your choice.
Click to expand...

At the end of the day, you are correct. To each his own but if I did not care or not respect the views and opinions from folk like yourself and other well informed Moparites, I would not be asking.
Truth be told. We don't drive our cars as most others do as we have the cars up here locked up from the end of October until (the earliest) Mid April. As for me, it's usually the 15th of April. Tax Day state side I believe, as well as my birthday present to me on that date...
Not to mention I usually will drive it once a week if I'm lucky, as the weather has been real shyty this yr, with rain.
Two wks ago we actually had a heat spell (for us at least) and it's been raining ever since and should carry on until next week, it was not bad earlier today so I tried to take it for a small drive and as usual if the car has not run for a week or two the bowls are empty by then this is why I am wanting to put an electric fuel pump ... Just for the start up but I am just going to go ahead and put it on for the sake of the battery draining as well....
Every time I try to start it... It sounds like it's telling me to " leave me alone lone, lone, lone, lone, lone. Leave me alone, lone, lone, lone...."
 
Had a holley red electric pump at the tank feeding the mech pump. Worked great for instant starts until the diaphragm in the mech pump let loose and pumped a few quarts into the crank case. Luckily only had to re-ring. Mech pump pulled through the holley red no problem, just used the electric before starting.
 
ok that's what I was thinking of doing but you just scared me with the pump dropping all that gas..
Was it because both were working at the same time?
 
You don't need to continue cranking to move fuel ! !
The diaphram pump continues to suck/push once the pump is cycled by 2 engine revolutions !
How often have you pulled the fuel line off an engine that hasn't run for a while, and had a shot of fuel spurt out, the pump maintains pressure/suction for quite a while after shutdown, and does so while starting too !

A post from years ago, good thread -

Best Fuel Pump Advice for Newb...
 
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MAPS said:
ok that's what I was thinking of doing but you just scared me with the pump dropping all that gas..
Was it because both were working at the same time?
Click to expand...
No, I had damaged the mech by incorrect installation previously. My dumb *** just didn't figure out what was going on until I had crazy blow by and the oil smelled gassy. Dammit
 
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