Help needed with fuel issue - The 1947 - Present Chevrolet & GMC Truck Message Board Network

VA72C10 · 12-27-2008, 09:57 PM

UPDATE:
I pulled the line coming in to the fuel pump and the gas immediately poured out. Luckily had my gas can there to catch it all (good to plan ahead sometimes) It filled up the 2 gallons (figured I'd put it back in and make sure I knew how much I had)

I'm guessing if the fuel is flowing (and looked decently clear) that that narrows it down to the fuel pump? I plan on going to the parts store this afternoon to pick a new one up. If it could be something else feel free to let me know

Original post
On my 69 shortbed I'm selling, I was going to drive it today to keep it running good for the next owner. It has always been hard to start, but ran like a top once started. Today, It will only start w/ gas added directly to the carb. It runs a few seconds until the gas runs out. It has one of the clear fuel filters on it (Has been on there for years from what I was told) I changed the filter today to see if that was an issue. No gas is coming through the filter at all. Obviously this is why it cuts off and won't start w/out adding gas to the carb. I know that there was/is bad gas in the tank from sitting. I have added a gallon of new gas but done nothing with the tank. I am guessing that the filter at the sender is clogged or that the fuel pump is bad. Anything to try before I pull the sending unit? Is there a way to check if it's the fuel pump? Would I be getting any gas pulled through the fuel pump even if it was bad w/ the engine running?

When it runs there is no smoke and it runs smooth and pretty strong for a stock engine. It ran just before I parked it a few weeks ago (but had to add gas to get it to start last time as well----only that time it continued to run once it started.)

If I do have to pull the sending unit, is there a way to move the stock bench forward enough to get to it w/out taking the bench all the way out?

Thanks for any help!

1968SWBBigBlock · 12-27-2008, 10:07 PM

I would double check and make sure you have fuel in the tank - sounds to me like you are out of gas.
You could also pull off the line between the pump and the tank and see if gas flows out (make sure to take off the gas cap)
Give it some time to keep flowing.
If you do not get any fuel out of the tank try running a line from a gas can to the fuel pump and start the motor and keep it running for a few seconds with fuel in the carb.
If it pulls fuel check before the pump - if not replace the pump

cdowns · 12-27-2008, 10:11 PM

disconect the line going to the pump and with very lo pressure and the gascap off blow air back into trank to unclog the fuel sock

VA72C10 · 12-27-2008, 10:13 PM

Quote:

Originally Posted by cdowns

disconect the line going to the pump and with very lo pressure and the gascap off blow air back into trank to unclog the fuel sock

I will try that as well when I have that line loose. Thanks!

100%Chevy · 12-27-2008, 10:52 PM

Might be the fuel pump.As said,see if it will pull gas from a can.If not,check the inlet to the pump,it may be clogged with old gas(thick,black stuff,very gummy,sticky).Almost nothing will cut this stuff!If it is,then the fuel line all the way to the tank will be the same,including the sock and the pick-up tube.
I pulled the tank on my 68 today,because of this.I've already replaced the fuel pump.The tank was litterally full of garbage.About 10 pounds of it!The sock was black and solid!It fell apart as I pulled it off the tube.I put some chain in the tank and cleaned on it for about 3 hours,constantly rinsing it with water.Put in new sending unit and pick-up.
Mine has buddy seats and I had to take them out to remove the tank.
So,I hope it's your fuel pump or you may be in for it!
Mike.

VA72C10 · 12-27-2008, 10:12 PM

Thanks for the fast response.

I was thinking of the gas can idea...just want to get someone to hold it so it doesn't tip while i'm testing things out. I just added a gallon and there was gas before (could hear it sloshing), plus the gauge shows about 1/2 tank. But i will add a couple more gallons first just to be sure it's being picked up.

VA72C10 · 12-29-2008, 01:43 PM

UPDATE:
I pulled the line coming in to the fuel pump and the gas immediately poured out. Luckily had my gas can there to catch it all (good to plan ahead sometimes) It filled up the 2 gallons (figured I'd put it back in and make sure I knew how much I had)

I'm guessing if the fuel is flowing (and looked decently clear) that that narrows it down to the fuel pump? I plan on going to the parts store this afternoon to pick a new one up. If it could be something else feel free to let me know

71tahoe · 12-29-2008, 03:44 PM

You can check the pump the same way you did the tank. If you have a hose to the carb take loose and run it into the gas can. If you have the steel line, take it loose and attach fuel hose and run it to a can. When it cranks, fuel should pump into the gas can. Good flow below the pump and no gas to the carb means bad pump. If you get fuel to the carb, you may have a filter completely clogged or a bad carb.

VA72C10 · 12-29-2008, 03:07 PM

ttt

**Palf70Step** · 12-29-2008, 03:11 PM

I would think the pump is the problem too.

VA72C10 · 12-29-2008, 03:50 PM

I have one of those " fire hazard" clear fuel filters so I can see if the fuel is flowing between the fuel pump and carb...which it was when i last had the truck running, but isn't now.

cdowns · 12-29-2008, 03:56 PM

if its a quadrajet carb it does have a fuel filter in the carb body/where the gas line enters the carb the very large nut take that off to access the carb filter

70rs/ss · 12-29-2008, 04:12 PM

If no fuel is getting into the clear filter, the pump is shot, i like to replace mine every few years just to be sure I don't get stranted!! They are only $15 at the parts store, more if you have to have a perf version, but it is the best $$$ you'll spend and the truck will fire right up, I'll bet!

12-27-2008, 09:57 PM	#1
VA72C10 VA72C10 Join Date: Mar 2008 Location: Midlothian, VA Posts: 25,269	Help needed with fuel issue UPDATE: I pulled the line coming in to the fuel pump and the gas immediately poured out. Luckily had my gas can there to catch it all (good to plan ahead sometimes) It filled up the 2 gallons (figured I'd put it back in and make sure I knew how much I had) I'm guessing if the fuel is flowing (and looked decently clear) that that narrows it down to the fuel pump? I plan on going to the parts store this afternoon to pick a new one up. If it could be something else feel free to let me know Original post On my 69 shortbed I'm selling, I was going to drive it today to keep it running good for the next owner. It has always been hard to start, but ran like a top once started. Today, It will only start w/ gas added directly to the carb. It runs a few seconds until the gas runs out. It has one of the clear fuel filters on it (Has been on there for years from what I was told) I changed the filter today to see if that was an issue. No gas is coming through the filter at all. Obviously this is why it cuts off and won't start w/out adding gas to the carb. I know that there was/is bad gas in the tank from sitting. I have added a gallon of new gas but done nothing with the tank. I am guessing that the filter at the sender is clogged or that the fuel pump is bad. Anything to try before I pull the sending unit? Is there a way to check if it's the fuel pump? Would I be getting any gas pulled through the fuel pump even if it was bad w/ the engine running? When it runs there is no smoke and it runs smooth and pretty strong for a stock engine. It ran just before I parked it a few weeks ago (but had to add gas to get it to start last time as well----only that time it continued to run once it started.) If I do have to pull the sending unit, is there a way to move the stock bench forward enough to get to it w/out taking the bench all the way out? Thanks for any help! __________________ Looking for a 67-72 swb or blazer project in or around VA. Last edited by VA72C10; 12-29-2008 at 01:44 PM.

12-27-2008, 10:07 PM	#2
1968SWBBigBlock Active Member Join Date: Oct 2006 Location: Ohio Posts: 1,643	Re: Help needed with fuel issue I would double check and make sure you have fuel in the tank - sounds to me like you are out of gas. You could also pull off the line between the pump and the tank and see if gas flows out (make sure to take off the gas cap) Give it some time to keep flowing. If you do not get any fuel out of the tank try running a line from a gas can to the fuel pump and start the motor and keep it running for a few seconds with fuel in the carb. If it pulls fuel check before the pump - if not replace the pump __________________ 1968 SWB 454 + .040, 490HP x 540 FT pounds of Torque 10-1 Kb Forged pistons, recon rods w/ ARP wave loc bolts 781 heads Ported with 2.19/1.88 SSTvalves Lunati 60204 cam, Micro Trol lifters, Ported Edelbrock Performer Rpm manifold armor coated, Pertronix Triple Strike Ignition Holley 770 Street Avenger carb,Headers armor coated Built by Watson Ruppel Performance in Sarahsville Ohio. Hardshift Tranny Built Turbo 350,TSI 10" 3000 stall 12 Bolt Eaton Posi 4.10 Richmond Gears moser axles 18.5" x 31" Hoosier Pro Street Radials ET Classic 5 Wheels - polished Power Steering, Power Brakes,Disc Brakes,Tach & Gauge Dash, Tilt,Factory Air (gone) Custom Paint & Body Work Special thanks to my wife, my son and my money tree

12-27-2008, 10:11 PM	#3
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Help needed with fuel issue disconect the line going to the pump and with very lo pressure and the gascap off blow air back into trank to unclog the fuel sock __________________ 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

12-27-2008, 10:52 PM	#5
100%Chevy Registered User Join Date: Jun 2008 Location: Moss Point,Ms. Posts: 1,439	Re: Help needed with fuel issue Might be the fuel pump.As said,see if it will pull gas from a can.If not,check the inlet to the pump,it may be clogged with old gas(thick,black stuff,very gummy,sticky).Almost nothing will cut this stuff!If it is,then the fuel line all the way to the tank will be the same,including the sock and the pick-up tube. I pulled the tank on my 68 today,because of this.I've already replaced the fuel pump.The tank was litterally full of garbage.About 10 pounds of it!The sock was black and solid!It fell apart as I pulled it off the tube.I put some chain in the tank and cleaned on it for about 3 hours,constantly rinsing it with water.Put in new sending unit and pick-up. Mine has buddy seats and I had to take them out to remove the tank. So,I hope it's your fuel pump or you may be in for it! Mike.

12-27-2008, 10:12 PM	#6
VA72C10 VA72C10 Join Date: Mar 2008 Location: Midlothian, VA Posts: 25,269	Re: Help needed with fuel issue Thanks for the fast response. I was thinking of the gas can idea...just want to get someone to hold it so it doesn't tip while i'm testing things out. I just added a gallon and there was gas before (could hear it sloshing), plus the gauge shows about 1/2 tank. But i will add a couple more gallons first just to be sure it's being picked up. __________________ Looking for a 67-72 swb or blazer project in or around VA.

12-29-2008, 01:43 PM	#7
VA72C10 VA72C10 Join Date: Mar 2008 Location: Midlothian, VA Posts: 25,269	Re: Help needed with fuel issue UPDATE: I pulled the line coming in to the fuel pump and the gas immediately poured out. Luckily had my gas can there to catch it all (good to plan ahead sometimes) It filled up the 2 gallons (figured I'd put it back in and make sure I knew how much I had) I'm guessing if the fuel is flowing (and looked decently clear) that that narrows it down to the fuel pump? I plan on going to the parts store this afternoon to pick a new one up. If it could be something else feel free to let me know __________________ Looking for a 67-72 swb or blazer project in or around VA.

12-29-2008, 03:44 PM	#8
71tahoe Registered User Join Date: May 2006 Location: Jonesboro, AR Posts: 916	Re: Help needed with fuel issue You can check the pump the same way you did the tank. If you have a hose to the carb take loose and run it into the gas can. If you have the steel line, take it loose and attach fuel hose and run it to a can. When it cranks, fuel should pump into the gas can. Good flow below the pump and no gas to the carb means bad pump. If you get fuel to the carb, you may have a filter completely clogged or a bad carb.

12-29-2008, 03:07 PM	#9
VA72C10 VA72C10 Join Date: Mar 2008 Location: Midlothian, VA Posts: 25,269	Re: Help needed with fuel issue ttt __________________ Looking for a 67-72 swb or blazer project in or around VA.

12-29-2008, 03:11 PM	#10
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 47,083	Re: Help needed with fuel issue I would think the pump is the problem too. __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!

12-29-2008, 03:50 PM	#11
VA72C10 VA72C10 Join Date: Mar 2008 Location: Midlothian, VA Posts: 25,269	Re: Help needed with fuel issue I have one of those " fire hazard" clear fuel filters so I can see if the fuel is flowing between the fuel pump and carb...which it was when i last had the truck running, but isn't now. __________________ Looking for a 67-72 swb or blazer project in or around VA.

12-29-2008, 03:56 PM	#12
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Help needed with fuel issue if its a quadrajet carb it does have a fuel filter in the carb body/where the gas line enters the carb the very large nut take that off to access the carb filter __________________ 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

12-29-2008, 04:12 PM	#13
70rs/ss Registered User Join Date: Dec 2004 Location: Northern AZ Posts: 7,271	Re: Help needed with fuel issue If no fuel is getting into the clear filter, the pump is shot, i like to replace mine every few years just to be sure I don't get stranted!! They are only $15 at the parts store, more if you have to have a perf version, but it is the best $$$ you'll spend and the truck will fire right up, I'll bet!



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