Carb. not getting fuel - The quest continues!

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BoweP

Member
Joined
Nov 15, 2015
Messages
18
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Location
Fresno, CA
My Car
1972 H code 351c, base
Maroon
So after browsing the forums and Web for people with similar issues, I've yet to find the solution to my new problem. After installing a new oil pan roughly a month ago, my car seemingly ran out of gas while idling . It has sat all that time until now (because of work). I decided to replace the fuel sender, and after disconnecting it, I drained roughly 4 gallons of nasty, cruddy gas out. From there, I replaced the fuel pump and flushed out the lines. Now, I'm not getting any gas pumped into my carb. After pouring a small amount into the carb, it will start and then eventally stumble and die within 5 seconds or so. I did that three or four times before calling it a night. And yes, there is gas in the tank :D ideas? Thank you

 
Did you reverse the lines at the pump accidentally? I did that once and it was a head scratcher for about 5 minutes.
Well, the fuel line that runs off the pump to the carb is metal and threads into the pump. When I bought the car from the original owner (5 months ago) it had been sitting in his garage for quite some time. It had a hard time starting when I bought it, but ran great when it did. I'm lost on this one!

 
Disconnect the hard line from the pump to the carb at the carb. Have it dump into something and turn the engine over to see if the pump works.

If it does it is the fuel filter or the needle and seat in the carb.

 
Verify that the fuel pump actually works. Connect a vacuum gauge to the inlet and see if it is sucking. Then connect a pressure gauge to the outlet and see if it is building pressure. If it is working you either still have a blockage someplace or a leak in the line between the tank and pump and it is sucking air instead of fuel.

 
Disconnect the hard line from the pump to the carb at the carb. Have it dump into something and turn the engine over to see if the pump works.

If it does it is the fuel filter or the needle and seat in the carb.
The hardliners turns into rubber line for a couple feet before meeting the carb. I disconnected it at my online filter (about 18 inches back from the the carb) and turned the engine over. No fuel dumped out at all. I'm beginning to suspect that my new fuel pump is faulty.



Did you replace fuel filter?
I replaced the fuel filter (s) before installing the new pump and sender. A little crud blew out of them, but nothing outstanding. No fuel before them

 
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My guess is you carb is full of the same crude you pulled out of the tank.
Even though I'm not getting gas at my in-line filter? I'm going to try the vacuum test that Don C suggested as soon as I can find the tools, but I think that there's also I high likelihood that I could also have a split in the line somewhere between the tank and the pump.

 
did you install the pump correctly so the arm is getting indexed by the eccentric lobe, some people have force the pump in and the arm went ontop of lobe and not under it so the arm never moves on the pump and is locked upwards.

 
did you install the pump correctly so the arm is getting indexed by the eccentric lobe, some people have force the pump in and the arm went ontop of lobe and not under it so the arm never moves on the pump and is locked upwards.
That is a possibility. It didn't feel forced but I am going to reseat it anyway. Is there a good diagram out there for the fuel line? While I'm at it, I'm going to run new line.

 
When you replaced the sender did you replace the rubber lines? Was the sender indexed with the fuel pick-up toward the bottom of the tank? I've seen rubber lines deteriorate internally and act like a check valve. What is the condition of the hard lines? Do you see any fuel leaks? Is the charcoal canister hooked up? If the tank isn't vented the fuel will not flow properly.

 
I have one of these that can be used for many different things:

http://www.autozone.com/test-scan-and-specialty-tools/vacuum-pump-brake-bleed-kit/oem-vacuum-pump/70116_0_0/?checkfit=true

That's the autozone version, I'm assuming that any FLAPS should have something similar.

Lots of good troubleshooting tips here. I would start with pulling the supply rubber line off of the pump and pull a vacuum on it. You can use the cup attachment in case everything is good and you get fuel. If not either the pump is bad or the tank isn't vented.

Let us know what you find.

-Matt

 
the build manual just shows you the basic shape and how the 2 piece line goes in and out of the apron, otherwise it is self explanatory during install follow the placement of the fuel line clips as you work back to the fuel tank. remember to inspect the rubber grommets that protect the fuel line through the engine aprons usually they are missing or falling apart now is the time to replace them as well. they reproduce them i think i got them from scott drake some years ago.

 
When you replaced the sender did you replace the rubber lines? Was the sender indexed with the fuel pick-up toward the bottom of the tank? I've seen rubber lines deteriorate internally and act like a check valve. What is the condition of the hard lines? Do you see any fuel leaks? Is the charcoal canister hooked up? If the tank isn't vented the fuel will not flow properly.
I didn't replace any of the line from the sender to the pump, though I'm wishing that I would have now. It is undoubtedly the original line. The hard line after the pump is seemingly in good shape with no leaks. The charcoal cannister is hooked up. I took off the gas cap and tried it, potentially thinking that I was not having ventilation. It still gave me nothing.

 
The eccentric on the cam pulley is just indexed with a metal tab. Am I remembering that correctly?

If that is the case the tab could have broken and spinning on the cam bolt.

 
Agreed the fuel now a days if you let the car sit for a month will gel up and clog up everything where you have to clean everything up. If your not going to drive it alot go to the hardware store or even wally world and purchase some marvel mystery oil and it will tell you how much to put in the fuel to "winterize" or store a vehicle with fuel in the system. mix it run it then your ok, otherwise you have to run it dry to avoid issues which you still wont be able to do 100%.

Disconnect the hard line from the pump to the carb at the carb. Have it dump into something and turn the engine over to see if the pump works.

If it does it is the fuel filter or the needle and seat in the carb.

Also remember you can unhook the lines at both ends and have someone blow air thru the front to the back put a small can over the end and hopefully it will disloge any crap in the lines might have to do it from the front to where it comes from the filter then behind the filter to the tank and see what comes out. if its full of crap then the tank might be full of stuff also replace the filter if you can it might have something clogging it since you had junk in the line. or if its servicable type open it and look inside you might be surprised what you see. if its full of rust you need to take the tank out and make sure its not needing to be replaced or fixed with tank coating.

 
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So I think that I have the issue tracked down. I bought a vacuum pump *thank you for that recommendation* and found out that I have good vacuum pressure at the pump. I can disconnect the hose at the sender (where it runs into the hard line two piece beginning) and have gasoline dumped on my hands. So, if I'm not crazy, it must be sucking air somewhere along the fuel line. Anybody had experience running new rubber fuel line as opposed to replacing the whole 2-piece?

 
So I think that I have the issue tracked down. I bought a vacuum pump *thank you for that recommendation* and found out that I have good vacuum pressure at the pump. I can disconnect the hose at the sender (where it runs into the hard line two piece beginning) and have gasoline dumped on my hands. So, if I'm not crazy, it must be sucking air somewhere along the fuel line. Anybody had experience running new rubber fuel line as opposed to replacing the whole 2-piece?
I run a non metal fuel line (EFI rated) from the tank to the engine compartment with no issues. I just followed the original path of the steel line.

If you have an air compressor just put air into the gas tank filler (Full tank is better as it takes less air) and use a rag to seal around the opening. It will force gas through the lines and if you have a leak you will find where the holes are real quick. Do this with the engine cooled so you don't have a fire if there is a leak on a hot surface. Doesn't take much air pressure to do this. If you have no leaks it will prime the system up to the fuel pump.

 
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