fuel supply - at my wits' end! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

cstanley · 04-19-2006, 03:00 PM

i can't figure it out. i must be missing something simple. i still can't maintain fuel supply after about 5 miles of run-time. i've replaced hoses, fuel pump, fuel cap, and tank sending unit (good news: fuel gauge works now!) i just can't figure it out! (see this post for my symptoms: http://www.67-72chevytrucks.com/vboa...d.php?t=191092)

i did, however, notice last night that the front vent hose (not yet replaced) that attaches to that smog canister by the battery was disconnected, and the restrictor inside the hose was shot. also, the cap on the canister looked to be missing. it hasn't always been that way, but i can't remember when it might have come off. could this be my problem?

maybe pressure is keeping fuel from flowing to pump? problem seems to be on the supply side of the pump. when it stops flowing, i disconnect the supply from the pump-no gas, but after a few moments, it will start to flow again.

I AM SO FRUSTRATED WITH THIS!!

diver547 · 04-19-2006, 03:53 PM

does your fuel lines run close to the exhaust?......possible vaperlock problem

cdowns · 04-19-2006, 04:01 PM

try running it without the gascap for a test run , also change the rubber hose section under the cab

cstanley · 04-19-2006, 04:48 PM

i'll check all those, thanks.
any thoughts on that canister? does it need to be hooked up?

Jayss109 · 04-19-2006, 05:08 PM

canister is not needed to make her run, just vents excess vapor to be burned off. Mine went to the scrap heap years ago, just plugged the hose coming outta the tank.

J
________
Russian recipes

qksilver · 04-19-2006, 05:14 PM

like cdowns said, sometimes the rubber hose will collapse under suction, even though it looks good on the outside, i ran into that problem on a couple of trucks because the P/O's didn't use fuel line but vacumm hose

cstanley · 04-19-2006, 05:50 PM

thanks, i'll make sure all my hoses are newly replaced.

cstanley · 04-25-2006, 11:01 AM

woo hoo!
i think it's fixed!

hopefully i'm not jinxing myself, but the initial testing stages indicate success. i really don't know exactly what the problem was, but i suspect it was a collapsed hose under the cab, as cdowns said. anyway, the result of my efforts are: a new fuel cap, new tank sending unit, new hoses, new fuel pump, new inline filter. now it'll go further than 5 miles and the fuel gauge works (hasn't worked in about 8 years.) the sending unit was shot, rusty, no longer had a filter, and the float arm was stuck. at least now i can leave the gas can at home.

all of that, and i'll soon be switching the tank to an under bed tank anyway.

oh well, that's the way i roll...

thanks everyone for your help! this site rocks!

04-19-2006, 03:00 PM	#1
cstanley Senior Member Join Date: Oct 2005 Location: Austin, TX Posts: 1,229	fuel supply - at my wits' end! i can't figure it out. i must be missing something simple. i still can't maintain fuel supply after about 5 miles of run-time. i've replaced hoses, fuel pump, fuel cap, and tank sending unit (good news: fuel gauge works now!) i just can't figure it out! (see this post for my symptoms: http://www.67-72chevytrucks.com/vboa...d.php?t=191092) i did, however, notice last night that the front vent hose (not yet replaced) that attaches to that smog canister by the battery was disconnected, and the restrictor inside the hose was shot. also, the cap on the canister looked to be missing. it hasn't always been that way, but i can't remember when it might have come off. could this be my problem? maybe pressure is keeping fuel from flowing to pump? problem seems to be on the supply side of the pump. when it stops flowing, i disconnect the supply from the pump-no gas, but after a few moments, it will start to flow again. I AM SO FRUSTRATED WITH THIS!! __________________ "Anybody who would paint his truck like this, would go to a minister's funeral dressed in feathers!" - Big Enis Burdett '72 Blazer Restoration Blog: http://sportchicken.blogspot.com/

04-19-2006, 03:53 PM	#2
diver547 Registered User Join Date: Apr 2006 Location: ohio Posts: 11	Re: fuel supply - at my wits' end! does your fuel lines run close to the exhaust?......possible vaperlock problem

04-19-2006, 04:01 PM	#3
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: fuel supply - at my wits' end! try running it without the gascap for a test run , also change the rubber hose section under the cab __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

04-19-2006, 04:48 PM	#4
cstanley Senior Member Join Date: Oct 2005 Location: Austin, TX Posts: 1,229	Re: fuel supply - at my wits' end! i'll check all those, thanks. any thoughts on that canister? does it need to be hooked up? __________________ "Anybody who would paint his truck like this, would go to a minister's funeral dressed in feathers!" - Big Enis Burdett '72 Blazer Restoration Blog: http://sportchicken.blogspot.com/

04-19-2006, 05:08 PM	#5
Jayss109 Active Member Join Date: May 2005 Location: San Jose, CA Posts: 235	Re: fuel supply - at my wits' end! canister is not needed to make her run, just vents excess vapor to be burned off. Mine went to the scrap heap years ago, just plugged the hose coming outta the tank. J ________ Russian recipes Last edited by Jayss109; 04-27-2011 at 11:38 PM.

04-19-2006, 05:14 PM	#6
qksilver Senior Member Join Date: Dec 2004 Location: Southern Pines NC Posts: 3,853	Re: fuel supply - at my wits' end! like cdowns said, sometimes the rubber hose will collapse under suction, even though it looks good on the outside, i ran into that problem on a couple of trucks because the P/O's didn't use fuel line but vacumm hose

04-19-2006, 05:50 PM	#7
cstanley Senior Member Join Date: Oct 2005 Location: Austin, TX Posts: 1,229	Re: fuel supply - at my wits' end! thanks, i'll make sure all my hoses are newly replaced. __________________ "Anybody who would paint his truck like this, would go to a minister's funeral dressed in feathers!" - Big Enis Burdett '72 Blazer Restoration Blog: http://sportchicken.blogspot.com/

04-25-2006, 11:01 AM	#8
cstanley Senior Member Join Date: Oct 2005 Location: Austin, TX Posts: 1,229	Re: fuel supply - at my wits' end! woo hoo! i think it's fixed! hopefully i'm not jinxing myself, but the initial testing stages indicate success. i really don't know exactly what the problem was, but i suspect it was a collapsed hose under the cab, as cdowns said. anyway, the result of my efforts are: a new fuel cap, new tank sending unit, new hoses, new fuel pump, new inline filter. now it'll go further than 5 miles and the fuel gauge works (hasn't worked in about 8 years.) the sending unit was shot, rusty, no longer had a filter, and the float arm was stuck. at least now i can leave the gas can at home. all of that, and i'll soon be switching the tank to an under bed tank anyway. oh well, that's the way i roll... thanks everyone for your help! this site rocks! __________________ "Anybody who would paint his truck like this, would go to a minister's funeral dressed in feathers!" - Big Enis Burdett '72 Blazer Restoration Blog: http://sportchicken.blogspot.com/ Last edited by cstanley; 04-25-2006 at 11:02 AM.



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