Fuel pump / carb feeding question..

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So my carb bowl is not filling with fuel, see nothing in window … replaced all fuel filters previously less than ur ago and car has Not been driven so they are brand new still…I’m replacing the fuel pump now bec I can tell it’s the original one from 1976 … figured I could just replace it with a new and not worry about it for a long long time.

my question is this:
When I’m doing the install i clamped off the fuel line hose that feeds it to remove and attach to new….** Should that fuel line (IF NOT CLAMPED) have fuel coming out ??? Or if nothing is coming it means there’s a plug somewhere in between?
 
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Yes, fuel should flow out of the line to the fuel pump.
Ok so to be more specific …

I had the car running after re-wiring 55% of the harness, because I had to remove heater core to get easy access to wiring for fixes - the coolant drained. When I went to fire it as said the engine started getting hot extra fast so the coolant hadn’t moved through the system yet. So I turned it off.
Ever since … carb bowl won’t fill enough to fire when turning key, plenty of battery power. (At least that’s my assessment / from sight of nothing in window and nothing going there after pumping gas pedal and re-trying).

(Sorry for long context)

so since then nothing in carb bowl, pump gas pedal plenty nothing while I try to fire and pumping gas pedal/holding it to ground. Still no fuel in window after 3-4 try’s.

… replacing OEM fuel pump with brand new OEM pump… as replacing is happening - nothing is coming out of hose that feeds pump .. nothing … with no clamp … (I did just put on the new metal oem fuel filter previously without running car) so maybe it hasn’t made its way through yet .. but NO fuel coming out of hose … though that was weird … clog???
 
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First thing, it may seem obvious; do you have plenty of fuel in there? Next, the pump creates suction from the tank side, then pushes up to the carb. I’ve seen in the past where the pump can’t create good suction from the tank because of the air in the lines; maybe try siphoning on the pump end of the line from tank? You should also be able to blow from the pump end back into the tank (loosen the filler cap) with your mouth or compressed air to see if there’s a blockage; if you don’t hear bubbling liquid, then there’s not enough fuel.
 
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Also, fuel should flow freely from the pump, but only if there is enough fuel present in the lines enough to create a siphon. No fuel from the line would point me to looking for a blockage or adding fuel. I’ve also seen guys pressurize the tank a little with compressed air through the filler neck to push fuel out the feed line.
 
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There is 100% enough fuel - both tanks are max capacity. I have a dual solenoid. Tested that - it’s fine… but I’m just stumped why fuel wouldn’t come out of line other than maybe it’s because the pump went out and hasn’t been suctioning any from the tanks while I’ve been trying to fire. I tried to start a couple times - bowl never filled because of whatever issue, and now that I’ve put new *Filter (OEM metal one, directly before pump), & then went to do pump as well - the clamp jumped off line and I figured oh here it comes and literally nothing no fuel coming out. So next thought Is either hasn’t made its way through the new filter or clog somrehrrr
 

flx

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Unplug the fuel line at the carb, put it in a plastic bottle or something, run the starter (unplug coil also) and see if you have pulses of fuel getting out. You'll now if it's a carb issue or before.

Can be a lot of things restricting the fuel delivery, on my Cruiser after a lot of search I finally found a soft fuel hose that was not correctly routed and was pinched by a sharp corner...
Start at the carb and go back along the line until you find where it restricts the fuel.
 
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Checked the float in the carb bowl? Maybe the needle valve is sticking closed.

i didn’t want to have to take the carb off and open up .. but I knew that could be a possibility. Also I re-painted my air filter cover and when you screw it on to the part on top of carb I was worried little chips of dry paint were failing in as I took on and off to check issues …
 
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Well I may be off base as I have a '73 and not a '76. In looking for information I noticed that the '76 has a feed and a return line. Is it possible that when changing parts you crossed up the connections and somehow got the return line from the tank connected to the fuel pump? I couldn't find a tank diagram but if the return simply dumps into the top of the tank then it wouldn't be able to pick up fuel in the tank. Just my guess.
 
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Well I may be off base as I have a '73 and not a '76. In looking for information I noticed that the '76 has a feed and a return line. Is it possible that when changing parts you crossed up the connections and somehow got the return line from the tank connected to the fuel pump? I couldn't find a tank diagram but if the return simply dumps into the top of the tank then it wouldn't be able to pick up fuel in the tank. Just my guess.
Good idea but no I double checked when doing it and just went out to triple check - thx for the idea though .. could have been a possibility
 

Pighead

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I think the first thing is determine why you are not getting fuel to the fuel pump.
In my limited experience, when you disconnect the fuel feed line from the pump, gas should pour out. I might disconnect the feed line from the tank, see if fuel is coming out of the tank. If yes then replace the feed line, if no then investigate the tank.
You can fill your float bowl through the slanty vent tubes over the venturis just so you can make it run for a minute.
 
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Well when I installed the dual tank solenoid gas poured out under there so if anything it’s in the metal line … but as I said I havnt tried to start since the bowl emptied, and then installed new filter and pump .. is it possible just from gravity/ new filter to go through it just can’t make its way through quite yet? - the line is at an upwards angle
 
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For it to just drain, the tank pickup would have to be higher than the fuel pump or filter inlet, and also have sufficient fuel to create head pressure to push that fuel out (fuel level higher than outlet). On my 71, I think the filter is slightly higher than the tank output. Are the dual tank solenoids hooked up reverse if possible? Like instead of the solenoid being pulled open, they are being held closed?
I’d start pulling connections at the tank end to see where fuel stops flowing. Or suck on the line at the fuel pump end to start a siphon.
 

SlapSmak

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Ok, so start at the line from fuel tank, that should go to the fuel filter, then to the pump, then from pump to carb. if you disconnect line to filter, do you have gas from tank?

if no, then prime the line, put a clear line on the other side of the fuel filter and suck with your mouth or with a hand pump. once you have fuel to there, then connect that line to pump and prime the other side of fuel pump using same method. Then connect the output line to carb and it should fill the carb bowl quickly. the pump will cavitate with air in the line and not pressurize the lines, especially if you have a blockage on the tank end.

If you cant prime fuel from the tank to filter connection, bad line or clog. Blow air in that line backwards with compressor, it should unclog. You will at some point need to drain the tank and clean out the gunk, or replace the lines.
 
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I'm having similar issues with my '78. It ran fine when parked last year but won't start now, not getting fuel to the carb. I have fuel to the pump as when I pulled the line at my filter, gas poured out. I have a trollhole carb so no return. If I have fuel to the pump, the pump should be good, correct? I'll have to pull the line at the carb to see if its a carb issue or a line issue, but I only run non ethanol premium, so it that shouldn't be an issue. It runs fine off of starting fluid.
 

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