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Offline Mytwojeeps2020

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Electric fuel pump
« on: December 06, 2021, 10:42:26 AM »
My pre-Chinese single action fuel pump used to fill the glass bowl up when the engine was running. Now, I’ve read they don’t do this anymore, which calls for a lot of cranking before the engine starts. Sometimes my CJ6 sits for a month between drives - it’s a camp Jeep, so I don’t see it often. When it does start, I have to keep the idle high so it doesn’t stall. I have to run it this way the whole time I’m using it.

I think I may have two problems here:

To fix the starting problem, I’m thinking of adding an electric fuel pump between the tank and the mechanical fuel pump. I’m thinking this will help fill the fuel pump so there’s less cranking.

The idle problem I can’t figure out. I’m running a Solex that’s recently been rebuilt. I’m in Florida so there’s no elevation issues. I also added a new fuel filter.

I replaced the Carter carb with a Solex about 100 hours ago (odometer doesn’t work). It worked fine until I had to replace the first of my cheap, POS Chinese fuel pumps last year due to their flooding my crank case with gas. After the fuel pump issues, I had the Solex rebuilt.

I’m also wondering this: once I get it started, should I keep the electric fuel pump on to assist the mechanical pump?
First Car at 16: 1958 CJ3B    (RIP)
Second Jeep: 1964 CJ6 (Re-homed in 2022)
Current Jeep: 1961 CJ5 “Olaf”

Offline scoutpilot

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Re: Electric fuel pump
« Reply #1 on: December 06, 2021, 12:24:54 PM »
I'm going to climb out on a thin limb with this one.
My pre-Chinese single action fuel pump used to fill the glass bowl up when the engine was running. Now, I’ve read they don’t do this anymore, (Actually, a full bowl indicates a problem. The air gap at the top is purposeful to help maintain pressure and has always been a feature.)which calls for a lot of cranking before the engine starts. Sometimes my CJ6 sits for a month between drives - it’s a camp Jeep, so I don’t see it often. (And that is why it is hard to start. The fuel has evaporated from the bowl.)When it does start, I have to keep the idle high so it doesn’t stall. (Sounds like a vacuum leak is present.) I have to run it this way the whole time I’m using it.

I think I may have two problems here:

To fix the starting problem, I’m thinking of adding an electric fuel pump between the tank and the mechanical fuel pump. I’m thinking this will help fill the fuel pump so there’s less cranking.
Buy a pump with a manual primer handle.

The idle problem I can’t figure out. I’m running a Solex that’s recently been rebuilt. I’m in Florida so there’s no elevation issues. I also added a new fuel filter.

I replaced the Carter carb with a Solex about 100 hours ago (odometer doesn’t work). It worked fine until I had to replace the first of my cheap, POS Chinese fuel pumps last year due to their flooding my crank case with gas. After the fuel pump issues, I had the Solex rebuilt.
You replaced the Carter with the Soles because of fuel pump issues?

I’m also wondering this: once I get it started, should I keep the electric fuel pump on to assist the mechanical pump?

When was the last time any of these original items was rebuilt? Have you done a good tuneup on the motor?
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Offline Mytwojeeps2020

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Re: Electric fuel pump
« Reply #2 on: December 06, 2021, 01:38:01 PM »
All good questions, SP.

As to the air gap in the bowl, when it's running, I only get a 1/4 or 1/3 inch gas level at the bottom. Maybe I was "mis-seeing" the old pump - it looked like the gas was at the top of the bowl, but you're right, it probably wasn't.

I know that the gas in the pump evaporates when the Jeep sits a long time. In the old days, I would place my mouth on the filler outlet and blow into the tank, which forced fuel into the bowl (too old for that now). That's why I'm considering an electric pump to "charge" the fuel pump. I didn't know about the manual primer handle until long after I installed the second fuel pump. Can't afford to go down that road again, so I'm considering the electric one as a "booster."

The Carter, literally, fell apart. In my ignorance I trashed it and bought a new Solex. Stupidly knows no bounds...It was an idiotic decision. The Solex was purchased well before I had the fuel pump issues, so no, I didn't replace the carb because of the fuel pump. The Solex was rebuilt about two running hours ago.

The engine was tuned up (plugs, points, etc.) before the fuel pump issues. It was running fine.

Thanks, SP.

Just as an FYI: Here's the link to my original fuel problems a year ago. https://cj3apage.com/Forum/index.php?topic=4833.msg38014#msg38014
A brand new fuel pump caused this former problem. Bad internal parts allowed it to pump gas straight into the crankcase.
 
« Last Edit: December 06, 2021, 01:44:00 PM by Mytwojeeps2020 »
First Car at 16: 1958 CJ3B    (RIP)
Second Jeep: 1964 CJ6 (Re-homed in 2022)
Current Jeep: 1961 CJ5 “Olaf”

Offline SteveKfl

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Re: Electric fuel pump
« Reply #3 on: December 06, 2021, 04:17:28 PM »
My suggestion, if you go the electric fuel pump route, make sure it has "pass thru capability" when "off" so the manual pump can still suck fuel thru it.
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Offline scoutpilot

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Re: Electric fuel pump
« Reply #4 on: December 06, 2021, 04:20:22 PM »
In the glass bowl pump, if the fuel level covers the brass screen the pump is working fine. Clarity is a good thing. What is the fuel pressure requirement for the Sole vs. the output pressure of the pump?

The problem with not running the Jeep for a month at a time is not the pump going dry, it is the fuel bowl in the carb going dry.
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Offline Bruce_W

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Re: Electric fuel pump
« Reply #5 on: December 07, 2021, 12:44:48 AM »
In the glass bowl pump, if the fuel level covers the brass screen the pump is working fine. Clarity is a good thing.

In the “old” pumps the bowl had to be 2/3-3/4 full to have fuel above the screen, which is necessary as Scout said. The air at the top acts as a cushion to the surge of the pump. The “new” (Chicom) pumps with the split bowl have their screen on the floor of the bowl so there is no way it can ever fill. If the bowl divider is cracked, chipped, or not perfectly aligned with the divider in the gasket, the pump will not pump. I’ve seen bowls on these that have actually turned out of alinement during use.
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Offline PercyUK

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Re: Electric fuel pump
« Reply #6 on: December 07, 2021, 02:39:40 AM »
 Hi, given a choice I wouldn't fit the electric pump, I think it is a lot of hassle and some additional expense trying to fix a system that should work just fine. Part of the problem is likely to be the Solex and may be the cause of some of your extra cranking. I have one and I always start it with two or three presses on the gas pedal to get a bit of fuel in the manifold (assuming some remains in the carb) and then the choke. I then leave the gas pedal until it fires. The idle may simply need adjusting. There is a mixture screw on the carb for the idle and if it is wound in too far it will never be happy. Next time you get her started and warmed up adjust the idle so that it is revving quite fast, then slowly turn the mixture screw in or out until it is running smooth and as fast as it will go. When done adjust the idle again and drop the revs to your liking. The adjusting screw is on the side that faces the rear of the Jeep and the idle mixture screw at the base of the carb facing the front.

Offline PercyUK

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Re: Electric fuel pump
« Reply #7 on: December 07, 2021, 04:43:49 AM »
Oh and it would be good to isolate the cause so I would suggest that before you attempt to start it again take the fuel line off the carb and stick it in a bottle. When you crank it you will be able to see how slowly or  quickly the fuel arrives. If it is quick i would revisit the carb. If it is super slow then the pump and lines may need addressing. Good luck.

Offline Mytwojeeps2020

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Re: Electric fuel pump
« Reply #8 on: December 07, 2021, 03:41:36 PM »
All good thoughts, my friends. I'll think things through and make a call. Thanks, much!
First Car at 16: 1958 CJ3B    (RIP)
Second Jeep: 1964 CJ6 (Re-homed in 2022)
Current Jeep: 1961 CJ5 “Olaf”