Am i having fuel drainage issies from the bowl ?

[candymancan]

Im not sure whats going on with my 76 J10. I rebuilt the carb.. cleaned it really good.. ran good in warmer weather but in cold.. it wont start after it sits for 2-3 days. Unless i pour a little gas in the carb directly.

My metal fuel line that comes up from the fuel pump broke so i dont hsve that S shape that goes above the carb level anyn8re. I had to hook up the fuel filter and line to the nroken off part. So the fuel filter sits below the carb now on the valve cover.

Is this the reason why ? It feels like gas is draining the bowl ? And i gatta get it really running to pump fuel back up through the line. Into the bowel ? Or am i wrong ?

Its weird.. after that it runs great. I bought a used S shape ir u shape line.. from a local guy but in my mess of rebuilding my bed i lost it.. i might tossed it one day cleaning my shop mistaking it fir another line i had..

I dunno. Thats frustratin

[tgreese]

Bowel is your large intestine. It's the float bowl.

IME it's your air cleaner. These carburetors tend to dry out through the bowl vents quickly even with the factory air cleaner. An open element makes them dry out even faster.

If you keep the filter level and the return on the top, it should not matter you are missing the original steel lines. An electric fuel pump is a common remedy for this problem.

[sierrablue]

Used to have that problem all the time on mine. Electric fuel pump definitely makes it better just because the engine doesn't have to crank for you to get fuel.

Personally I'd get a longer hose for the return line and cut out some of the fuel hose on the actual functional line, until you can get the fuel filter to sit dead horizontal, as this SHOULD prevent the filter from draining the bowl.

Mine got harder and harder to cold start as the mechanical fuel pump was dying; you might check that; even if it's new if it's had gross gas run through it it might be torn up and you're getting less gas from every pump than it was designed to. When it was getting like that I'd crank it once for a long time without pumping the gas because I knew there was no fuel there anyway, then I'd let the starter cool down, then start spamming the gas as I cranked it again until it caught.

As Tim said could also be the air cleaner, and would easily be solved by an electric fuel pump.

[candymancan]

Bowel is your large intestine. It's the float bowl.

IME it's your air cleaner. These carburetors tend to dry out through the bowl vents quickly even with the factory air cleaner. An open element makes them dry out even faster.

If you keep the filter level and the return on the top, it should not matter you are missing the original steel lines. An electric fuel pump is a common remedy for this problem.

i have the same cleasner on my wagoneer and it has no issues

[candymancan]

Used to have that problem all the time on mine. Electric fuel pump definitely makes it better just because the engine doesn't have to crank for you to get fuel.

Personally I'd get a longer hose for the return line and cut out some of the fuel hose on the actual functional line, until you can get the fuel filter to sit dead horizontal, as this SHOULD prevent the filter from draining the bowl.

Mine got harder and harder to cold start as the mechanical fuel pump was dying; you might check that; even if it's new if it's had gross gas run through it it might be torn up and you're getting less gas from every pump than it was designed to. When it was getting like that I'd crank it once for a long time without pumping the gas because I knew there was no fuel there anyway, then I'd let the starter cool down, then start spamming the gas as I cranked it again until it caught.

As Tim said could also be the air cleaner, and would easily be solved by an electric fuel pump.

i see what ur saying ya my return line is like 2 feet long anyway i was meaning to cut it back some, but ill cut back the line to the carb to get the filter further in that line instead.

This Jeep had an electric pump on the frame by the fuel tank, but i was told that can damage the mechanical pump. so i removed it.

It just seems like the bowel is empty when i try to start it, adding fuel to thee carb gets it running, but it dies 3 seconds later, then another shot of fuel in the carb and it stays running once the bowl fills up im assuming

[tgreese]

I've made this point before, but nobody believes me. Fuel cannot drain back from the float bowl. The inlet to the bowl is above the level in the bowl. You cannot siphon through free air.

You've got evaporation, leakage through the accelerator pump (you will see this as dripping from the accelerator pump cover), or drainage/leakage through the gasket around the power valve (or a ruptured power valve). No siphoning aka "drain back." The exit through the main jets is also above the level of fuel in the bowl.

If there is fuel in the bowl and you have spark, the engine will start. If you want to experiment, instead of pouring fuel into the venturi to start, try putting a small amount of fuel into the float bowl through one of the bowl vents. If the engine starts, this kinda confirms the bowl was dry. A dry bowl also will not make a pump shot; that's something else to try - you can see the squirt of gas looking down the throat of the carb and twisting the throttle (engine off!).

It is possible for the fuel plumbing (not the bowl!) to drain back. There are reed valves in the fuel pump that should keep furel in the lines and in the fuel filter. If the fuel filter were empty, I'd suspect the fuel pump.

If you cut one of these fuel filters open, you will find a pin hole feeds the return line. It's very simple - the return is metered by the size of the tiny hole.

[Curly]

I've made this point before, but nobody believes me. Fuel cannot drain back from the float bowl. The inlet to the bowl is above the level in the bowl. You cannot siphon through free air.

Thank you for making that point! It drives me nuts when I see someone on the 'net suggesting the fuel ran out of the bowl and back into the pump. How did it get past the Needle/seat? How about those carbs with the inlet in the top of the carb!

[candymancan]

I've made this point before, but nobody believes me. Fuel cannot drain back from the float bowl. The inlet to the bowl is above the level in the bowl. You cannot siphon through free air.

You've got evaporation, leakage through the accelerator pump (you will see this as dripping from the accelerator pump cover), or drainage/leakage through the gasket around the power valve (or a ruptured power valve). No siphoning aka "drain back." The exit through the main jets is also above the level of fuel in the bowl.

If there is fuel in the bowl and you have spark, the engine will start. If you want to experiment, instead of pouring fuel into the venturi to start, try putting a small amount of fuel into the float bowl through one of the bowl vents. If the engine starts, this kinda confirms the bowl was dry. A dry bowl also will not make a pump shot; that's something else to try - you can see the squirt of gas looking down the throat of the carb and twisting the throttle (engine off!).

It is possible for the fuel plumbing (not the bowl!) to drain back. There are reed valves in the fuel pump that should keep furel in the lines and in the fuel filter. If the fuel filter were empty, I'd suspect the fuel pump.

If you cut one of these fuel filters open, you will find a pin hole feeds the return line. It's very simple - the return is metered by the size of the tiny hole.

Ive wondered if it can even drain back due to the inlet with the needle being up high. But if i remember right. The rebuild kits was a little lower than the factory one. Ill pop the carb top off after sitting for 3 days and see if fuel is still in there or not.

Ill check my fuel filter too. Im sure there was a reason for Jeep to sit the fuel filter above the carb inlect at an angle though.

Pretty sure my fuel lines drain though. When i had the tank off and i was using a can. The fuel cank sitting on the ground would turn rusty sitting overnight due to the fuel draining back into the can. This was 6 months ago of course with the lines all rusted and gunked up inside. I changed the filter two times now in 200 miles due to partical accumilation from the old lines.

Its doing its job though. As i had a sticky float after the first filter change and i had to pop the carb top off at the dump. Due to fuel pouring out of the vents from the needle being stuck. The bowl was clean.


I just wanna get this running like my 90. My starts perfrctly. Eveb after ny rebuild this one is very finicky. I cant get the high idle ti even come on when i first atart it so i gatta throttle it slightly to 1500rpm with my foot or it dies immediatly. And the heated choke isnt openeing all the way i alwaya have to puah on the plastic arm to get it to open. It stays fully open then. But then it wont close when cold and i gatta manually close it.

Its annoying.

[will e]

My carbureted 73 mustang has a mechanical fuel pump. If I let it sit too long the fuel evaporates from the carburetor. Cranking the engine does not provide enough fuel/pressure to quickly fill the bowl but if I crank for a long period of time it eventually will fire up. Cranking for a long time is not recommended.

So if it doesn't fire up after pumping the gas once or twice I dribble a bit of fuel into the bowl. This gets the engine to spin fast enough for the fuel pump to supply the carb.

I try to start it at least once a week and when I do it faithfully fires up each time.

The OP mentions in the next to last paragraph of the previous post that the choke system is not working correctly. I believe this is more than likely his main issue.

[tgreese]

If you have sediment coming from the gas tank, that will get into the fuel pump. The particles will hold the reed valves open and 1) make your drain back worse and 2) send less fuel to the carburetor.

There is a filter sock in the gas tank that should screen out the bigger particles from the tank. It's on the end of the fuel pickup tube.

You could add a second fuel filter between the tank and the fuel pump. That will reduce the pump output some, but normally the pump delivers way more fuel than the engine needs. IME fuel delivery is fine even with the extra filter. You can run with the return line stoppered too, and see if that helps. You could drop the tank and check the filter sock.

Suggest you remove the automatic choke and install a Dorman manual choke kit.

This truck is nearly fifty years old, and considerably older than your GW. Trucks generally lead a hard life before they are retired, and then retired for good reason.

[candymancan]

If you have sediment coming from the gas tank, that will get into the fuel pump. The particles will hold the reed valves open and 1) make your drain back worse and 2) send less fuel to the carburetor.

There is a filter sock in the gas tank that should screen out the bigger particles from the tank. It's on the end of the fuel pickup tube.

You could add a second fuel filter between the tank and the fuel pump. That will reduce the pump output some, but normally the pump delivers way more fuel than the engine needs. IME fuel delivery is fine even with the extra filter. You can run with the return line stoppered too, and see if that helps. You could drop the tank and check the filter sock.

Suggest you remove the automatic choke and install a Dorman manual choke kit.

This truck is nearly fifty years old, and considerably older than your GW. Trucks generally lead a hard life before they are retired, and then retired for good reason.

Gas tank was super clean inside besides the hamd sized patch on top i cut out and welded new steel from rust (outside ) the tank. Thr only rust sediment is in the lines themselves. Which now has had 3 filters and 60 gallons of gas go through em. 400 miles or so ive driven the Jeep now.

The heated choke element was broken so i fixed it. Then it worked but only partially it opens about 50% on its own.. adjusting the high idle and heated choke arms is confusing to me. Ive watched many videos but the old timers explaining do it to fuddy duddish or too quickly because there so good at it. So it makes a dummy like me not get it.

Plus mine has a brolen plastic arm someone tied a wire wrap it so it isnt 100% anyway. Id like to have the choke working. But the fast idle doesnt work either. That another issue. No kick down or fast idle. Just the high idle in park and curb idle

I gatta hold the gas pedal slightly to estimate where itll rev too 1500rpm or so and hold it there for like 15 seconds then release or itll die. And thats annoying as well.

My 90 has 2x the mileage on it. My 76 has 85k as a plow my 90 has 160k nearly.

[candymancan]

My carbureted 73 mustang has a mechanical fuel pump. If I let it sit too long the fuel evaporates from the carburetor. Cranking the engine does not provide enough fuel/pressure to quickly fill the bowl but if I crank for a long period of time it eventually will fire up. Cranking for a long time is not recommended.

So if it doesn't fire up after pumping the gas once or twice I dribble a bit of fuel into the bowl. This gets the engine to spin fast enough for the fuel pump to supply the carb.

I try to start it at least once a week and when I do it faithfully fires up each time.

The OP mentions in the next to last paragraph of the previous post that the choke system is not working correctly. I believe this is more than likely his main issue.

This is exactly what i have to do if it sits for more than 3-4 days.

Everyone mentions electric fuel pump im starting to realoze this is why someone had installed one on this thing.

[tgreese]

Fuel pump won't solve your fast idle problem.

Suggest you replace the plastic arm and follow the adjustment instructions that came with your rebuild kit. Also pg 4-30 forward in the '76 TSM.

Highway miles are way less stressful than city/work miles. Plow work is brutal.

[tgreese]

Also, this truck has a thermostatic choke. The choke stove has to be connected to the choke assembly via the hot air tube. Clean air comes from the air horn.

The choke is 100% thermostatic; I expect performance depends on sufficient exhaust traveling through the intake manifold bypass while the engine is cold. This relies on the damper (heat riser, blocking flap) between the passenger exhaust manifold and the exhaust pipe.

If the choke activation does not work now, kinda think you are flogging yourself to try and make it work. Even with the Dorman manual choke kit, you'll need that little plastic arm to get a fast idle. You need the screw to work with the fast idle cam.
https://www.carburetor-parts.com/motorc ... el-85-100b

[letank]

My fuel filter is on the top of the inner fender, no issues, even when it was below the carb on a previous set up with the mechanical fuel pump

fuel74c.jpg

[hanger]

I have an edelbrock 1405 on my 87 GW and it will evaporate overnight if I park it in the heated garage. Have to pour some fuel down the carb to get it started or else let it crank forever.

[rocklaurence]

Dont forget that these need the spacer between the intake and carb. They are notorious for the heat from the engine boiling out the fuel once theyre shut down. I make sure to have the spacer and an electric fuel pump.