Fuel System Help, PLEASE! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

72c20?c10 · 10-12-2005, 04:04 PM

I installed a ECE rear mount fuel tank in my 72 long bed.
The tank has a fuel pick up near the center of the tank and another fuel line connection in the front right corner. I called ECE and they said it was a vent.
I plumbed the tank using the stock aux tank fuel neck which has a built in vent tube (I think it is a vent tube) so I ran the vent line to it.
If I put the gas cap on is this a vent then? Where does it get it's venting?
I can't get gas to the carb.
I have an edelbrock electric fuel pump with an edelbrock fuel filter mounted on the crossmember near the tank. The fuel line runs to the rear of the engine up to the carb. Before the carb I have a glass fuel filter. Then the carb has a built in fuel filter. I heard you can't have too many fuel filters.
With the key on the pump pumps but no fuel gets to the carb.
Any suggestions. I will start a tear down diagnostic this evening.
I hope whomever reads this can stay awake to the end and help me.

ECE was no help. They are concerned with the tank only.

Thanks in advance.

bejay · 10-12-2005, 04:37 PM

sounds like you have the vent hooked up correctly it is a vent to allow the air to escape from the tank while filling with gas it is not a vent when the gas cap is on.

**pjmoreland** · 10-12-2005, 04:42 PM

You could try disconnecting the fuel line from the output of the fuel pump and activate the pump to see if fuel is making it that far.

cdowns · 10-12-2005, 05:20 PM

disconnect the fuel line to the pump and suck on it to see if gas will come out the tank

67ChevyRedneck · 10-12-2005, 05:50 PM

There should be two vent holes in the tank. There should be one next to the big filler neck spout that you should have connected the filler neck vent to. The other is a vent for the tank itself so that a vacuum is not created when the gas cap is on. I am going to install a blazer tank myself and am not sure how I am going to do this yet. Take the gas cap off and see if you can get fuel to the carb, if you can, you have a vent problem. You may also have a bad fuel pump??? Here's a thread I started for a blazer tank, but same idea. I might try the motorcycle vent things on ebay. Post #'s 4,6,8,9,11, and 14 should help some.

Cool cap/blazer tank vent thread

Longhorn Man · 10-12-2005, 05:59 PM

Personally, I'd drop all those filters too. You only need one good filter. More just adds strain on the pump. Besides, with a (assumed) new tank, there should be no reason at all for all the filters.

cdowns · 10-12-2005, 06:04 PM

another thought have you verified the direction of flow of the fuel pump??? if you have the inlet side going to the carb and the outlet side going to the tank it won't pump well in that direction

rauto13 · 10-14-2005, 01:07 AM

I have an aluminum tank from Classic Performance, it only has the fuel fill fitting, a fitting at the bottom of the tank for the fuel supply line and the fitting in the top right for the vent. I run a two line mechanical fuel pump (one in, one out). The tank is vented from the fitting on the top of the tank to the fuel fill. I have a fill neck from a mid 90's Chevy pickup and can use a vented gas cap. If your truck will run without the gas cap on, you might see if a vented gas cap is available for your truck fuel fill.

**kwmech** · 10-14-2005, 01:17 AM

I think the 'vent' line and the fuel line are crossed. The vent usually is in the center of the tank.

72c20?c10 · 10-14-2005, 11:56 AM

That is what I thought too.
Then as I was making my connections, I noticed the connection in the forward corner was open to the entire tank and connection in the center of the tank has a tube of some sort going to the bottom of the tank. Is this the pickup tube?

Thanks for your help!

Chevy4Life · 10-14-2005, 02:29 PM

Here is a shot of my ECE tank. The vent is on the top right. I just used a piece of 3/8" alum. fuel line bent over the front of the tank. I have not pulled gas through it yet, but it sounds like with the cap on you have no vent. I'd try a vented cap or bypass the vent on the filler tube.

BubbaGreen · 10-14-2005, 07:55 PM

Dont think that because it's a *new* tank that it is clean.....I purchase a tank as well from ECE, the fuel injected version, and it was FULL of metal shavings....I took it to the local car wash and flushed it thoughly....let it dry and still had some more cleaning to do. Make sure YOU check you tank.

10-12-2005, 04:04 PM	#1
72c20?c10 Registered User Join Date: Jul 2004 Location: So. Cal. Posts: 9	Fuel System Help, PLEASE! I installed a ECE rear mount fuel tank in my 72 long bed. The tank has a fuel pick up near the center of the tank and another fuel line connection in the front right corner. I called ECE and they said it was a vent. I plumbed the tank using the stock aux tank fuel neck which has a built in vent tube (I think it is a vent tube) so I ran the vent line to it. If I put the gas cap on is this a vent then? Where does it get it's venting? I can't get gas to the carb. I have an edelbrock electric fuel pump with an edelbrock fuel filter mounted on the crossmember near the tank. The fuel line runs to the rear of the engine up to the carb. Before the carb I have a glass fuel filter. Then the carb has a built in fuel filter. I heard you can't have too many fuel filters. With the key on the pump pumps but no fuel gets to the carb. Any suggestions. I will start a tear down diagnostic this evening. I hope whomever reads this can stay awake to the end and help me. ECE was no help. They are concerned with the tank only. Thanks in advance. __________________ Eschew Obfuscation

10-12-2005, 05:20 PM	#4
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	disconnect the fuel line to the pump and suck on it to see if gas will come out the tank __________________ 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

10-12-2005, 05:50 PM	#5
67ChevyRedneck Hittin E-Z Street on Mud Tires Join Date: Nov 2004 Location: Greenville, SC Posts: 23,090	There should be two vent holes in the tank. There should be one next to the big filler neck spout that you should have connected the filler neck vent to. The other is a vent for the tank itself so that a vacuum is not created when the gas cap is on. I am going to install a blazer tank myself and am not sure how I am going to do this yet. Take the gas cap off and see if you can get fuel to the carb, if you can, you have a vent problem. You may also have a bad fuel pump??? Here's a thread I started for a blazer tank, but same idea. I might try the motorcycle vent things on ebay. Post #'s 4,6,8,9,11, and 14 should help some. Cool cap/blazer tank vent thread __________________ Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications! Last edited by 67ChevyRedneck; 10-12-2005 at 05:53 PM.

10-12-2005, 06:04 PM	#7
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	another thought have you verified the direction of flow of the fuel pump??? if you have the inlet side going to the carb and the outlet side going to the tank it won't pump well in that direction __________________ 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

10-14-2005, 01:07 AM	#8
rauto13 saving one more Join Date: Sep 2005 Location: Pryor Creek, Oklahoma Posts: 3,066	I have an aluminum tank from Classic Performance, it only has the fuel fill fitting, a fitting at the bottom of the tank for the fuel supply line and the fitting in the top right for the vent. I run a two line mechanical fuel pump (one in, one out). The tank is vented from the fitting on the top of the tank to the fuel fill. I have a fill neck from a mid 90's Chevy pickup and can use a vented gas cap. If your truck will run without the gas cap on, you might see if a vented gas cap is available for your truck fuel fill. __________________ 72 Chevy longbed - now for parts 69 Chevy short fleet - needing some love 70 RS Camaro - needing more love driver - 96 GMC X-cab

10-12-2005, 04:37 PM	#2
bejay Registered User Join Date: Aug 2005 Location: missouri Posts: 136	sounds like you have the vent hooked up correctly it is a vent to allow the air to escape from the tank while filling with gas it is not a vent when the gas cap is on.

10-12-2005, 04:42 PM	#3
pjmoreland Senior Member Join Date: Jan 2005 Location: CA Posts: 5,981	You could try disconnecting the fuel line from the output of the fuel pump and activate the pump to see if fuel is making it that far.

10-12-2005, 05:59 PM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Personally, I'd drop all those filters too. You only need one good filter. More just adds strain on the pump. Besides, with a (assumed) new tank, there should be no reason at all for all the filters.

10-14-2005, 01:17 AM	#9
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,630	I think the 'vent' line and the fuel line are crossed. The vent usually is in the center of the tank.

10-14-2005, 11:56 AM	#10
72c20?c10 Registered User Join Date: Jul 2004 Location: So. Cal. Posts: 9	That is what I thought too. Then as I was making my connections, I noticed the connection in the forward corner was open to the entire tank and connection in the center of the tank has a tube of some sort going to the bottom of the tank. Is this the pickup tube? Thanks for your help! __________________ Eschew Obfuscation

10-14-2005, 02:29 PM	#11
Chevy4Life Senior Member Join Date: Feb 2003 Location: Las Vegas, NV Posts: 749	Here is a shot of my ECE tank. The vent is on the top right. I just used a piece of 3/8" alum. fuel line bent over the front of the tank. I have not pulled gas through it yet, but it sounds like with the cap on you have no vent. I'd try a vented cap or bypass the vent on the filler tube. Attached Images

10-14-2005, 07:55 PM	#12
BubbaGreen Senior Member Join Date: Mar 2001 Location: Cedar Park, TX Posts: 686	Dont think that because it's a new tank that it is clean.....I purchase a tank as well from ECE, the fuel injected version, and it was FULL of metal shavings....I took it to the local car wash and flushed it thoughly....let it dry and still had some more cleaning to do. Make sure YOU check you tank. __________________ 71 Chevy C-10 SWB Fleetside RamJet-350/4L60e & Compushift/3.73Posi See it at www.prismnet.com/~grzanich



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