Fuel Problems on 78 Corvette

[aal4034]

So I just replaced my fuel pump with a brand new one (I thought the old one went bad). I'm still not getting any fuel from the pump up to my fuel line and into the carburetor. I've tried bypassing the fuel line into the carb and testing it straight from the pump--no luck. My question is, what else could it be? Is the problem with the fuel pump still? Is there a problem in between the tank and the pump? Or is there a problem in the tank? Also, someone told me there might be a filter in the tank or and in-line filter between the tank and the pump that could be clogged. Is there any truth to that? Thanks for the help.

1978 Corvette Silver Anniversary 350 small block L48

 

[Hib Halverson]

Welcome to the CAC.

Get the car up on jack stands and carefully inspect all fuel hoses and pipes from the tank forward along the right frame rail up to the pump inlet. Look for collapsed or kinked hoses or pinched fuel pipes. In the unlikely event you find an inline gas filter under the car somewhere, replace it.

If you don't find any of that, drain the tank then remove the pick-up assembly from the tank and inspect the filter "sock" on the end of the pick-up.

Let us know what you find.

 

[bill81vette]

Welcome to CAC!!
enjoy!!!!
I'm going to move this to the C3 section

 

[Paul T]

There is a short (4" ?) S shaped hose coming off the fuel pump. On my 79 that hose would collapse under load. Idle was okay. It's hard to tell what it is doing by just looking at it. Replace it and any other rubber hosing you can get to just to make sure.

 

[aal4034]

I followed the lines all the way to the tank and no where did I find linked or collapsed lines. I figured out that it's gotta be something between the tank and the pump. I went ahead and bypassed the fuel tank by sticking a hose into a 5-gallon gas tank to see if it'll suck up there. It did and my car started to turn on.

If none of the lines are blocked and I didn't find an in-line filter, what could be the issue in the tank?

 

[Paul T]

I followed the lines all the way to the tank and no where did I find linked or collapsed lines. I figured out that it's gotta be something between the tank and the pump. I went ahead and bypassed the fuel tank by sticking a hose into a 5-gallon gas tank to see if it'll suck up there. It did and my car started to turn on.

If none of the lines are blocked and I didn't find an in-line filter, what could be the issue in the tank?

See Hib's suggestion above.

 

[hoosierdaddy]

Welcome to Corvette Action Center

How much fuel is in the tank, if low maybe the pickup line sock, screen that is in the tank on the end may be plugged or fell off. If it pulls fuel from a 5 gallon container seems apparent to me the problem is in the tank somewhere; correct You said started to turn on, so you did not actually run it; correct? But if you basic eliminated the OEM tank out of the picture and unless I'm missing something you're conveinced it would have ran on the 5 gallon makeshift tank, has to be something in the tank. . . . Again maybe I've missed something though :duh Thorugh the process of elimination if I'm understanding what you did it has to be in the tank, if in fact you used the same fuel line and etc. and the only difference is the makeshift fuel tank substitute. . . . Good luck and keep us posted, by the way

-Bill

 

[Hib Halverson]

You're going to have to pull the tank pick-up/sender assembly.

The instructions on how to do that are in the factory service manual.

Considering the age of the car, I wouldn't try to fix the pick-up, I'd just replace it. I'd also replace all the rubber hoses in the rear which are between the tank and the fuel lines.

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