79'gmc K25

BAD2500HD · January 18, 2008

I just go a 1979 GMC K25 4X4 with the 350 4bl carb what the problem is is if it sets for up to a week (sometimes less) it doesn't seem to get any gas in the carb it will start right up if you put a little in it (gas) you can pump it and it just doesn't seem to get any , the pump looks new and it runs great , there doesn't seem to be any gas leaks that i can find , could it be the float in the carb ? i would really like to get this little problem solved any help would be great.

Fortune50 · January 19, 2008

I just go a 1979 GMC K25 4X4 with the 350 4bl carb what the problem is is if it sets for up to a week (sometimes less) it doesn't seem to get any gas in the carb it will start right up if you put a little in it (gas) you can pump it and it just doesn't seem to get any , the pump looks new and it runs great , there doesn't seem to be any gas leaks that i can find , could it be the float in the carb ? i would really like to get this little problem solved any help would be great.

So, you're saying that the carb goes dry when it sits? Does it eventually start w/ priming or is it not starting at all right now? Is it a quadrajet? It sounds like the float bowl itself has issues if fuel is leaking out of it and it's getting dried up. The fuel has to go somewhere and if it's not seen on the outside then it's going down into the intake. Might need to have it rebuilt and the float bowl checked out for warpage or just buy an entire rebuilt unit thru the aftermarket. I've never worked on quadrajets, but I have on thermoquads, and they're really bad about cracking fuel bowls because they're made of plastic!

If you're talking about fuel not even getting to the carb, then that's different. You may have a fuel line or hose leaking or the fuel pump diaphragm is bad allowing gas to leak out. Also, a clogged fuel line/hose or gas tank pick up won't help either in trying to draw fuel to the pump.

BAD2500HD · January 19, 2008

I just go a 1979 GMC K25 4X4 with the 350 4bl carb what the problem is is if it sets for up to a week (sometimes less) it doesn't seem to get any gas in the carb it will start right up if you put a little in it (gas) you can pump it and it just doesn't seem to get any , the pump looks new and it runs great , there doesn't seem to be any gas leaks that i can find , could it be the float in the carb ? i would really like to get this little problem solved any help would be great.

So, you're saying that the carb goes dry when it sits? Does it eventually start w/ priming or is it not starting at all right now? Is it a quadrajet? It sounds like the float bowl itself has issues if fuel is leaking out of it and it's getting dried up. The fuel has to go somewhere and if it's not seen on the outside then it's going down into the intake. Might need to have it rebuilt and the float bowl checked out for warpage or just buy an entire rebuilt unit thru the aftermarket. I've never worked on quadrajets, but I have on thermoquads, and they're really bad about cracking fuel bowls because they're made of plastic!

If you're talking about fuel not even getting to the carb, then that's different. You may have a fuel line or hose leaking or the fuel pump diaphragm is bad allowing gas to leak out. Also, a clogged fuel line/hose or gas tank pick up won't help either in trying to draw fuel to the pump.

It seems like the carb is dry if i prime it with a pouring a little gas in the carb it will fire right up i'm just guessing on the float i just didn't know if the float would somehow let the gas back out of the carb but then again it shoulded go anyfurther then the fuel pump right ? so maybe even if the pump looks new it could be bad and letting the gas back threw it ??