Flooding the Carb

[plym_46]

Re check your float level, assure the pivot pin is in straight and the retention clip is fully down the slot.  Then check the needle and seat for dirt or debris.  Last but not least assure that you do not have a leaky float.  Sometimes they will get pinholes in them that allow fuel to seep in.  This will lower the float allowwing to much fuel into the bowl.  This will show up after shut down becase of residual pressure in the line.  Also what is the pressure rating on the electric pump?  If its more than 7#'s, it could be overpowering the needle and seat.  To check the float, remove it and shake it listening for some sloshing.  If you have liquid inside, place it is a small pan of water and slowly increase the temp of the water to simmer.  This will force the gas out, and you can see the bubbles showing you the leak.  Solder the hole shut and you should be good to go.

Reacting to today's higher fuel volitility, I set my float slightly lower than factory spec.  I believe this allows the fuel to expand in the float bowl without flooding, especially after shut down on hot days

[Go Fleiter]

Bill, I just put a switch (with a beautiful metal lever). A Relais can do it too. The modern layouts have a control device to stop the pump in case of an accident. As this is only available in 12 V, I just shut the E-pump off when the engine runs. While running, the mechanical pump does it perfectly.
Wish You a nice season!! Go

[Bill James]

Go, I have one question about doing an electric fuel pump in parallel with the mechanical pump, did you use a simple swith to operate the pump, or did you use a relay? I have all the parts now to try this on my 1931 PA, but I'm thinking of hooking it up through an old horn relay.
You hit on my problem exactly with your remark about excess cranking to get fuel up to the carburetor. I'm useing a down draft carb, and the gas leaks back through the mechanical pump. After the car sets for a few days I have to almost run the battery down getting fuel to the carb. It also has to be bad for the poor old starter motor. I'm hoping this will solve my problem, Thank you for the idea and the drawing. Bill james

[Go Fleiter]

again, with text - avoiding to search the whole post later... Go 

[Go Fleiter]

John I run it parallel not to bother each others funktion.
I cut the gas hoses in front and back of the mechanical pump, put 2 pieces of T- Tube and had a parallel path for e-pump and diirectional valve. Fixed all just wiht hose clamps.
Greetings! Go

[John Hendricks]

Go-that is a good idea.  Do u runthe electric pump in series or parallel with the mechanical pump?

[Go Fleiter]

I put a 12 V pump getting a lower pressure with the 6 V variety.
I just use it to flood the carb for 10 to 20 seconds after a long rest or after a short rest with hot engine to avoid the vapor lock problem. I than just switch it off.
So the starter isn?t overburdend by having to crank the engine for lots of  minutes only to move the  mechanical gas pump.
The latter has directional valves built in, the e-pump got a extra valve, so the gas doesn?t take the wrong way.
While running, the old mechanical pump works perfectly.
Greetings! Go

[John Hendricks]

When i bought my 40 PU back in the late 80s, it had an electric fuel pump and ran just OK.  The PO had left the mechanical pump on the block. Even tho the electic pump was set at the lowest setting it seemed to over pressurize the carb.  After I had dismantled the vehicle and restored it, I simply got a new pump from NAPA , hooked it up and the carb still seemed over pressurized.  after several carb rebuidings, a "new" rebuilt carb, and finally a new old stock carb, it runs fine and doesn't leak.  I can't tell u about the dynamics of using both electric and mechanical pumps, but from my experience and what others have said on this forum, the mechanical pump will do fine if everything else is OK.  I know more about carbs now than I did back then, but I still can't get that original carb to run right. And the supposedly rebuilt carb had a buggered up needle valve and idle curcuit. They have become  parts donors and sit on the shelf along with the electric 6 volt pump.

[rbergman]

  Fellow 46-47-48 P-15 Plymouth Owners

I purchased  a 47 Plymouth  P-15 Special Deluxe a few months ago and have been working on the carb, engine,  and the electrical system for the past several weeks.  Recently  I had the carb rebuilt.  Before I rebulit the carb I installed a new electrical fuel pump. The car was running OK prior to rebuilding the carb however, I had a few flat spots and  a few episodes with hard starting.  I wanted to ensure that I had a reliable daily driver.  Prior to rebulding the carb the car was running off a new electric fuel pump only.  Given that the previous owner included a new mechanical fuel pump with the car when I bought  it, I decided while the carb was being rebulit I would install the mechanical fuel pump and run all new lines.  I installed the rebulit carb and tested the fuel feed line prior to completing the final hook up to the carb.  I got a good clean stream of fuel.   I turned the key on, pulled out the choke 3/4's out, hit the gas peddle two times, and heard the clicking of the electrical fuel pump, my buddy who was under the car indicated that the fuel filled the bowl  in the mehanical fuel pump, and the old girl sprung to life.  No leaks all was well...I drove it a few miles and retunrned to do some fine tuning on the carb.  We hooked up the dwell meter and set the carb idle to 500 RPM's.  Turned the mixture screw in until she began to lope.  Backed the screw out until she settled in to a smooth idle.  All was well...I thought.  A few days later I tired to start her.  She flooded and would not start.  Waited about three hours and the same thing happened.  When I looked under the hood the fuel was running out of the accelerating pump and the new gaskets were wet with fuel.   This happended several more times.

After all this my questions are:  If you have both an electric and a mechanical fuel pump hooked up  and operational, will the fuel pressure exceed what the small carb can take and therefore flood.  Why did it work for a short time? It is possble the float is stuck?  Do you recommend using the mechanical or the electrical? I can bypass either one and leave the one disconnected as a back up.

I am very new at this and would appreciate your expert advice

Thanks,

Sheriff Rick ( Retired)

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