Hello and welcome to Packard Motor Car Information! If you're new here, please register for a free account.  
Login
Username:

Password:

Remember me



Lost Password?

Register now!
FAQ's
Main Menu
Recent Forum Topics
Who is Online
119 user(s) are online (41 user(s) are browsing Forums)

Members: 3
Guests: 116

humanpotatohybrid, a rose, bkazmer, more...
Helping out...
PackardInfo is a free resource for Packard Owners that is completely supported by user donations. If you can help out, that would be great!

Donate via PayPal
Video Content
Visit PackardInfo.com YouTube Playlist

Donate via PayPal



(1) 2 »

Electric Fuel Pump (again, with a twist)
#1
Just can't stay away
Just can't stay away

Todd W. White
See User information
Hello to all you fellow Packard owners. I have read every post on this subject I can find on the forms and still have some questions.

Let me set this up this way:

I have a 1949 Deluxe Touring sedan with a 288 engine in it. The fuel pump is a dual style that was rebuilt by Max Merritt. The carburetor is the Carter WDO-type which was professionally rebuilt locally. My gas tank has been professionally cleaned inside and out and has been coated with the proper type of chemical sealant/liner. My problems with keeping the engine fed with fuel have been solved, with one exception:

When it sits for a day or two, or if it's extremely hot, if it doesn't start immediately, it is unfair to try to get it to. I do not like to crank it over and over again, so I end up pulling the breather off the carburetor, pouring a little bit of fuel in the car, and starting it that way. Then it runs just fine.

Based on the advice of many, I added an electric fuel pump made by the Holley Corporation back near the fuel tank. The holy technical service man recommended their Mighty Mite Fuel Pump, and their technical support expert assured me that it did not hinder fuel from flowing through it when it was turned off. It is a 12 volt DC unit, so I ran a dedicated pair from a 6 to 12 volt converter I installed under the dash directly to the 12-volt inputs of the fuel pump. I installed a momentary push button switch that completes the circuit to the input of the converter, and I use it to activate the pump when I need it.

However, even after all of this, I'm having the same issue. No matter how long I let the pump run, it doesn't seem to help the carburetor and the fuel system to go ahead and allow the car to start. I have verified that the flow of the electric pump is correct, it's not wired in reverse, and there's nothing blocking the hoses. Once I get it running, it runs just fine, but I just can't get it to start using the priming pump.

My question is this:

Is it possible that the electric fuel pump is functioning as a "check valve" on the fuel supply line as it arrives from the electric pump? In other words, is the mechanical pump preventing the freshly pressurized fuel in the fuel line from making it to the carburetor? Would I be better off allowing the electric one to run for a given time before I started up?

Posted on: 8/4 14:36
Todd W. White
Sapulpa, Okla.
1949 2262 DeLuxe Eight Touring Sedan
 Top  Print   
 


Re: Electric Fuel Pump (again, with a twist)
#2
Home away from home
Home away from home

humanpotatohybrid
See User information
Mechanical fuel pumps work through a double-check-valve spring-diaphragm system so just a slight fuel pressure should be enough to flow through both check valves and fill the carb.

How long do you leave it on? Might need to be 10 sec or more.

Posted on: 8/4 14:41
1955 400 | Registry | Project Blog
1955 Clipper Deluxe | Registry | Project Blog
1955 Clipper Super Panama | Registry
 Top  Print   
Like (1)
 


Re: Electric Fuel Pump (again, with a twist)
#3
Just can't stay away
Just can't stay away

Todd W. White
See User information
I've tried various times, nothing more than about 15-20 seconds, for fear of damaging the mechanical pump, even though the Holley pump is rated at 4-7 psi output pressure.

Posted on: 8/4 14:46
Todd W. White
Sapulpa, Okla.
1949 2262 DeLuxe Eight Touring Sedan
 Top  Print   
 


Re: Electric Fuel Pump (again, with a twist)
#4
Home away from home
Home away from home

Ross
See User information
Unhook your fuel line at the carburetor, hold it over a can, and see if the electric pump pumps through.

Posted on: 8/4 15:11
 Top  Print   
Like (1)
 


Re: Electric Fuel Pump (again, with a twist)
#5
Just can't stay away
Just can't stay away

Todd W. White
See User information
That's my next step - thanks for the encouragement!

Posted on: 8/4 15:14
Todd W. White
Sapulpa, Okla.
1949 2262 DeLuxe Eight Touring Sedan
 Top  Print   
 


Re: Electric Fuel Pump (again, with a twist)
#6
Forum Ambassador
Forum Ambassador

HH56
See User information
If you have the optional glass bowl filter next to the carb you could also check and see how long it takes to fill that bowl. Modern gasoline -- at least the stuff sold here in Calif -- appears to be more volatile compared to the older 50s fuel. After you park the car the fuel sitting over a hot manifold tends to bubble or percolate away fairly quickly leaving an empty carb. In my cars sometimes the electric pump needs to run for several minutes to fill the tubing between the pump and filter and then fill the filter and carb float bowls. I usually keep it on while starting the engine and then after the engine is running and stable turn it off.

Posted on: 8/4 15:28
Howard
 Top  Print   
Like (1)
 


Re: Electric Fuel Pump (again, with a twist)
#7
Home away from home
Home away from home

53 Cavalier
See User information
I know this is stating the obvious, but something is wrong.

a) You should not require an electric fuel pump, especially considering you have a rebuilt mechanical pump.

b) After sitting for only a day or two there should be more than enough fuel in your carburetor still to allow your car to start right up.

I don't understand the need for electric fuel pumps. I started my 53 Cavalier this spring after sitting for 5 months without priming it. To be fair it did have to turn over more than usual.

I just replaced the fuel line from the pump to my carburetor today, so that line was completely dry, and my car didn't miss a beat when I started it. (It hadn't been started for a couple of days.)

I've had many vehicles with mechanical fuel pumps and none of them ever needed an electric fuel pump.

Before the carb and pump were rebuilt, was the car running fine? When you say it doesn't start on a hot day, do you mean after it's been running, or just when it's hot out it doesn't start?

Maybe you have a vacuum leak? Carb not sealed properly to the intake? Maybe a bad accelerator pump? If you hold the choke open and pump the gas, can you see it spray into the carb?

Maybe the carb, or the fuel pump, or both, are faulty? Bad rebuilds happen. It sounds like you've gone through your entire fuel system, which is good, but it also makes it all suspect. Because once the car starts it runs, then it seems like the tank and fuel line to the pump would be fine. Also it seems that the fuel supply, which you can check, shouldn't be an issue either given you have a rebuilt mechanical pump which works when the car is running, and you also have an electric fuel pump. If after a couple of tests you find that you're getting lots of fuel supply, I would question if there is maybe something wrong with the carb.

All this to say, I don't think the problem was the lack of an electric fuel pump, which also means it's not the solution.

Posted on: 8/4 17:46
 Top  Print   
Like (1)
 


Re: Electric Fuel Pump (again, with a twist)
#8
Home away from home
Home away from home

Packard Don
See User information
I only ever had one Packard with an electric pump (one should not be necessary) and it was the 6v diaphragm type (it was on my 1953 Clipper Deluxe when I bought it) so its check valves did not interfere with fuel flow when it wasn't running. It was also pressure- sensitive so even if it didn't have a switch, it could be left on (although it rarely was) as it pumped only when needed and then only a couple "bumps" when turning on the key and maybe an occasional one on the road. I can't recall if AC, Carter of someone else but I have accumulated several of them both 6v and 12v that I use primarily on a temporary bases for priming a freshly rebuilt fuel system.

Point of this rambling is that the modern vane type of pump can actually block the fuel flow BUT they should still provide enough to get the engine started quickly and that yours is not seems to imply that something else is wrong. Maybe check the flexible line before the stock pump which you can do only by removing it. It may seem nice and pliable on the outside but could have closed up on the inside. If it's okay, then maybe the screen inside the fuel pump is plugged.

Posted on: 8/4 18:04
 Top  Print   
Like (1)
 


Re: Electric Fuel Pump (again, with a twist)
#9
Home away from home
Home away from home

Joe Santana
See User information
You know, of course, to use the electric fuel pump for a few seconds, if you have one, again, not essential, press the accelerator one time to the floor to close the choke, and then start it when cold. When hot, hold the accelerator to the floor and hold it there until it starts. That is a great carburetor. I’ve got a beat up one that works as well as the Stromberg that was rebuilt at great expense by one of the most reputable rebuilders (they rebuilt it again to make it work right).

If the carb is getting fed plenty of fuel, it could be your distributor adjustment, too advanced or retarded. Someone here would know which direction would cause the problem you’re experiencing.

Posted on: 8/4 19:20
 Top  Print   
Like (1)
 


Re: Electric Fuel Pump (again, with a twist)
#10
Webmaster
Webmaster

BigKev
See User information
Impulse style eletric pumps usually will allow the mechanical pump to pull through it when it's off. Rotary style eletric pumps will not.

My 54 has had an impulse in the back near the tank for 15+ years. I only use it to prime when it's been sitting for extended period. Otherwise, I'm running off the mechanical during normal operation. No extra check values, regulators or lines used.

Posted on: 8/4 20:04
-BigKev


1954 Packard Clipper Deluxe Touring Sedan -> Registry | Project Blog

1937 Packard 115-C Convertible Coupe -> Registry | Project Blog
 Top  Print   
Like (1)
 




(1) 2 »




Search
Recent Photos
Photo of the Day
Recent Registry
Website Comments or Questions?? Click Here Copyright 2006-2024, PackardInfo.com All Rights Reserved