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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Joec123able on November 11, 2015, 02:14:02 pm

Title: Carb problem
Post by: Joec123able on November 11, 2015, 02:14:02 pm
I have a 77 k-10, all stock. ran it out of gas the other day. Put about 5 gallons in the tank and did the old put alittle gas in the carb to get it running again about 30 times with no success. I've discovered that gas is making to the carb but is not making it through the carb to keep the truck running. So the problem is in the carb, does anyone know what the problem could be and how to fix it? I'm guessing it's a stuck float or something in the carb but My skills are very minimal.
Title: Re: Carb problem
Post by: Jason S on November 11, 2015, 05:38:12 pm
Have you checked the fuel filter for trash?
Title: Re: Carb problem
Post by: blazer74 on November 11, 2015, 06:57:11 pm
Probably sucked up crap from the bottom of the tank and in the lines and filter and carb.
V
Common scenario with running out of gas .
Title: Re: Carb problem
Post by: 1979mmx350 on November 12, 2015, 02:15:05 am
Like the others have said, if you aren't leaking out of your tank and it's not coming out through the carb, then your issue lies somewhere in between. Should be a simple fix once you narrow it down tho. Don't worry too much!
Title: Re: Carb problem
Post by: Joec123able on November 12, 2015, 04:41:03 pm
Okay I'm just confused, when I just crank the engine there's no fuel running to the carb. When I pour gas in the carb and get it running then it starts to pump gas but not much. So the first assumption would be the fuel filter, do both gas tanks run through the same fuel filter (mounted just in front of the fuel pump)? And why when I took the fuel filter off did no gas come leaking out the fuel filter and lines feel bone dry) Sorry if I sound like an idiot because I am lol. I can't figure it out. Another thing, it's a Mechanical fuel pump the runs off the crank, there are three hoses one has a fuel filter going into the pump and one goes up to the carb, I can't figure out what the third hose is.
Title: Re: Carb problem
Post by: Irish_Alley on November 12, 2015, 05:44:22 pm
there should be a filter in the carb if original. there could be a inline filter also but both tanks should share a filter or two. if you take the fuel inlet hose off the carb does fuel come out of this line?
Title: Re: Carb problem
Post by: Joec123able on November 12, 2015, 08:13:17 pm
there should be a filter in the carb if original. there could be a inline filter also but both tanks should share a filter or two. if you take the fuel inlet hose off the carb does fuel come out of this line?
No fuel comes from any lines unless I pour gas straight in the carb and get it running, then a small amount squirts from the carb inlet hose, as far as I know just turning the engine over should be pumping fuel to the carb and it's not.Yes there is two fuel filters, a small one right in the carb and then another one right before the fuel pump as seen here on the left. The Hose on the left is the fuel in hose the one on the right in out to the carb, the middle I have no clue what it is. I just replaced the fuel filter haven't checked if that fixed yet, have to wait til tommorow.

(http://i1354.photobucket.com/albums/q681/joec123able/Mobile%20Uploads/image_zpslu5aydxd.jpeg) (http://s1354.photobucket.com/user/joec123able/media/Mobile%20Uploads/image_zpslu5aydxd.jpeg.html)
Title: Re: Carb problem
Post by: st3vomettler on November 12, 2015, 08:24:23 pm
If you take off the line running to the carb and try to syfine it (try to suck the fuel from the tank) does it seem like it's trying  to draw fuel or just sucking air
Title: Re: Carb problem
Post by: Joec123able on November 12, 2015, 08:43:22 pm
If you take off the line running to the carb and try to syfine it (try to suck the fuel from the tank) does it seem like it's trying  to draw fuel or just sucking air


Good idea I'll try tomorrow!
Title: Re: Carb problem
Post by: st3vomettler on November 12, 2015, 08:45:35 pm
Ok my 77 c10 does that when it runs out of gas and I got to draw it to the pump or it will drain my battery. And if it sucks air try putting some more gas in it it might not be enough to pick up
Title: Re: Carb problem
Post by: Joec123able on November 12, 2015, 09:14:34 pm
Ok my 77 c10 does that when it runs out of gas and I got to draw it to the pump or it will drain my battery. And if it sucks air try putting some more gas in it it might not be enough to pick up

Thanks man, that gives me some hope!
Title: Re: Carb problem
Post by: Jason S on November 12, 2015, 10:00:35 pm
Does anything change when selecting either tank?

So the first assumption would be the fuel filter, do both gas tanks run through the same fuel filter (mounted just in front of the fuel pump)?
Yep. If you have dual tanks and from your photo, the fuel is pulled from whichever tank is selected, runs through the tank line to the tank switch solenoid/valve, then filter, then fuel pump and possibly a second filter at the carburetor.

Quote
When I pour gas in the carb and get it running then it starts to pump gas but not much.
From the photo and your descriptions, I'd suspect the filter before the fuel pump and the fuel pump are both culprits.  The fuel pump has a "rubber" diaphragm inside that will weaken over time and eventually break. Not knowing the truck and engine condition -  if the fuel filter(s) and fuel pump are over three years old, then I'd consider replacing them.
Title: Re: Carb problem
Post by: Joec123able on November 12, 2015, 10:22:07 pm
Thanks for al the awesome information I truly appreciate it. The fuel pump and filter are pretty old because this truck sat unused for a long time and is just now getting back into being used. I've replaced the fuel filter if that doesn't do it then I'll be moving onto the pump next! Glad these old trucks are pretty Simple.
Title: Re: Carb problem
Post by: Joec123able on November 13, 2015, 12:43:22 pm
She's fixed!! It ended up being the 5 buck fuel filter that was keeping it from running! Thanks for the help! Now on to the next problem lol
Title: Re: Carb problem
Post by: rich weyand on November 13, 2015, 01:11:16 pm
Thanks for letting us know.  It helps us help out other people in the future.