no fuel going to rear carb

[hatepotholez]

So I found something strange. My rear carb is not being fed fuel at times. I disconnected the fuel lines from each carb and placed plastic bottles on each line. I then put fuel in the bowls and let the car run.

Doesn’t matter if it’s a mechanical or electric pump. If the front fuel line is plugged the rear will get fuel. I’m guessing it’s either clogged fuel lines in the rail or the return valve(this is not installed) or whatever that sits near the coil.

 

 

Any thoughts?

 

thx

 

 

 

 

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[jfa.series1]

That definitely sounds like a partially blocked fuel rail.  I suggest removing it from the car and back flushing it with whatever pressure you can apply - perhaps an aerosol brake cleaner product.  I'd start at the rear carb port, block the front carb port, and have a wire inserted in the supply port to break up any material that arrives.  Then block the rear carb port, repeat the process for the front carb port.  If the return line is open, you'll see some output during the process - that could also be a tiny wire insert to break up anything.  Check your results by applying liquid under pressure at the supply port to see if both carb ports are open.  The flow guide valve under the coil only handles vapors, not a likely culprit.

[hatepotholez]

Thanks, Ill try this out. I am also wondering if the lines from the tank to the pump are good. All lines are new including fuel and brake, even though the car sat unused for over 10 years.. The rail is original. 

Edited December 3, 2018 by hatepotholez

[hatepotholez]

Ok ran brake cleaner through the rail and compressed air, still getting very low pressure, low enough that it barely fills the carb bowls. If the tank is not vented properly can this affect the flow? I put new hoses from the tank to the vent tank but maybe the connections are crossed.

I also have to check the lines from the tank to the pump. Kind of hard now since I have a full tank of gas.

Lastly i’m going to try and get a remote fuel tank connected to the pump directly and see if that helps.


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[siteunseen]

Have you tried removing the gas cap?

I ran mine off a 2 gallon gas jug in front of the radiator. Take the supply line off the fuel pump and put it in the jug.

[hatepotholez]

sure did, unfortunately no difference.


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[hatepotholez]

next step is like what you mentioned. I can’t do anything until I get this fuel flow up to spec.


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[hatepotholez]

ok good news and bad news. Good news is I think i found the issue. I ran a remote fuel bottle and the fuel pump sucked it through quick and maintained high float levels.

I then blew air through the fuel line from the tank and gas was gushing out. After this I stuck a borescope down into the fuel tank and saw large pieces of the coating floating all around. This is what must of caused the fuel system to have low volume, it must of partially clogged the fuel exit port. After this I reconnected the fuel line and the floats were at a much higher level and the car was running very smooth. The floats still need to be adjusted but the tank has to be cleaned first. Ah what a sigh of relief!! Dreading dropping the tank though ??‍♂️


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[siteunseen]

Have you installed a clear filter coming out of the tank? A fram g3 works better on 240's smaller hose in my opinion.  They're  cheap to. You might use a couple and get the crud if it's  not too bad.  240 tanks are jobbie job!  You have to deal with all the evap hoses.

Edit: G2 is the 5/16 for 240s. G3 is 3/8 for 280s.  My bad.

Edited January 4, 2019 by siteunseen

[hatepotholez]

On 1/4/2019 at 3:56 PM, siteunseen said:

Have you installed a clear filter coming out of the tank? A fram g3 works better on 240's smaller hose in my opinion.  They're  cheap to. You might use a couple and get the crud if it's  not too bad.  240 tanks are jobbie job!  You have to deal with all the evap hoses.

Edit: G2 is the 5/16 for 240s. G3 is 3/8 for 280s.  My bad.

I installed a few filters, but they weren't clear. It's not really crud, more like big flakes of lining floating around. 

I'll see if I can upload the video. 

 

Edited January 7, 2019 by hatepotholez

[siteunseen]

Here's what came with mine, free of charge.

 

 

[siteunseen]

To add to my reply, none of that crud would stick to a magnet.  Car sat for 10 years with fuel in it.  It was just crumbly crud that smelt like fuel. I even tried to burn a piece with no luck. I think the fuel and moisture combined to make that mess?

Let me know if I can help, I have the threads with evap sizes from O'Reillys auto and what I bought from Lowe's. Also my Jimmy rig for the 90 degree turn on the top hose. Two 3/4" PEX fittings works great. Shade tree restoration, no show winner stuff.