No fuel flow??
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No fuel flow??
Hi guys, thanks in advance for any help. Been having continuous trouble with fuel flow on this 78 corvette.
1) originally would hesitate when hitting the gas, so I rebuilt carburetor including accel pump, still would hesitate.
2) very hard start on a warm engine
Now, I went to start the car, I get absolutely no fuel in the carb. Pumping continuously and not a drop comes in.
I ordered a new delco mechanical fuel pump, and just pulled the old pump and line to the carb. No fuel spilled out as I disconnected the old fuel pump?? I thought these were gravity fed from tank? Didn't have to clamp off or plug the lines that connected to old pump... do I have something going on before the fuel pump, as in the tank and lines? Anything to check between tank and pump?
Any thoughts would be appreciated, thanks.
1) originally would hesitate when hitting the gas, so I rebuilt carburetor including accel pump, still would hesitate.
2) very hard start on a warm engine
Now, I went to start the car, I get absolutely no fuel in the carb. Pumping continuously and not a drop comes in.
I ordered a new delco mechanical fuel pump, and just pulled the old pump and line to the carb. No fuel spilled out as I disconnected the old fuel pump?? I thought these were gravity fed from tank? Didn't have to clamp off or plug the lines that connected to old pump... do I have something going on before the fuel pump, as in the tank and lines? Anything to check between tank and pump?
Any thoughts would be appreciated, thanks.
Last edited by 1978BackToLife; Aug 5, 2016 at 02:42 PM.
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Joined: Apr 2009
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From: Charlotte NC
If you checked for your fuel supply line is flowing fuel....then....
You BETTER have someone spin your engine over WHILE you press and hold in the push rod that contact your camshaft and make sure that it moves in about 1/2"
I have had one where the lobe of the cam to drive the fuel pump was really badly worn along with end of the shaft and it would not move enough to make the fuel pump work when it got hot.....but would work when the car was cold. It drove me crazy til I found it.
DUB
You BETTER have someone spin your engine over WHILE you press and hold in the push rod that contact your camshaft and make sure that it moves in about 1/2"
I have had one where the lobe of the cam to drive the fuel pump was really badly worn along with end of the shaft and it would not move enough to make the fuel pump work when it got hot.....but would work when the car was cold. It drove me crazy til I found it.
DUB
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I think I'm completely beside myself, as this might be the most simple fix in the world and I did every major repair around it but this one.
I hooked up a vacuum pump to the fuel feed line, and it doesn't hold a vacuum. I blew into the line and could hear air coming out, and funny enough a bubble or two in the tank.
I pulled the gas lid, and the fuel line flex hoses are completely dry rotted. I can't believe it... If this is the problem, then the whole carburetor rebuild for accelerator pump, the fuel pump job... all unnecessary hahaha. Except for them being original equipment and needing to be rebuilt or replaced anyhow, but that's not the point. I'll be buying a couple $1 hoses today and kicking myself tonight.
I hooked up a vacuum pump to the fuel feed line, and it doesn't hold a vacuum. I blew into the line and could hear air coming out, and funny enough a bubble or two in the tank.
I pulled the gas lid, and the fuel line flex hoses are completely dry rotted. I can't believe it... If this is the problem, then the whole carburetor rebuild for accelerator pump, the fuel pump job... all unnecessary hahaha. Except for them being original equipment and needing to be rebuilt or replaced anyhow, but that's not the point. I'll be buying a couple $1 hoses today and kicking myself tonight.
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Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
For what this is worth...I go to a place like Oreilly's and get the 'bio fuel hose'. It has green writing on it and is rated a lot higher (220 psi if I am not mistaken).
I know regular 3/8' fuel hose is rated at 50 psi. And I know you are not a fuel injected engine. But when I am doing this..I prefer to use a hose that I know is overkill and I do not have to deal with again. And with the 'stuff' they add to fuel and often times do not tell us about...I figure the bio fuel hose is a safe bet.
I have found...even though it is a pain. I remove the rear bumper cover so I can easily replace the fuel supply and return with these bio fuel hoses.
DUB
I know regular 3/8' fuel hose is rated at 50 psi. And I know you are not a fuel injected engine. But when I am doing this..I prefer to use a hose that I know is overkill and I do not have to deal with again. And with the 'stuff' they add to fuel and often times do not tell us about...I figure the bio fuel hose is a safe bet.
I have found...even though it is a pain. I remove the rear bumper cover so I can easily replace the fuel supply and return with these bio fuel hoses.
DUB
