Fuel issues: lines plugged and smell in cab - The 1947 - Present Chevrolet & GMC Truck Message Board Network

just_ridin · 04-13-2017, 03:35 PM

Hey guys...picked up a '72 beauty for cheap in Atlanta!

the more you look the more is wrong with her, of course, but she's purdy as heck.

Fuel stench in the cab. Obviously a new tank with EEC.

There are 3 lines coming off the fuel tank and routing under the cab to the engine bay, two are plugged.

Wondering a few things here, input would be appreciated.

1) where should the 3 lines be heading in the first place that all's running ok with two of them plugged?

2) Any venting issues or reasons for the smell to be in there so strongly with new tank/sending unit other than a bad seal/gasket on the sending unit?

new sending unit along with the fuel tank, finally getting the seat out to have a look at everything and see if the moron who was in charge didn't get the seal right on the sending unit (hopefully simple cause for the stench).

Really hoping for answers on the 3 lines/2 plugged bit.

thanks!!

GASoline71 · 04-13-2017, 03:48 PM

My 1972 GMC has the EEC monkey motion too. I plugged off the lines to the EEC and then switched over from a non vented to a vented fuel cap. I even removed the EEC lines out of the passenger rear cab pillar. My truck has never had a smell in the cab. Unless I make a hard right turn with a full tank of fuel... lol.

Gary

just_ridin · 04-13-2017, 05:41 PM

OK...so on the '72 there's a line to the fuel pump and a return line if you're running fuel injection...what's the third one for?

**Steeveedee** · 04-13-2017, 06:44 PM

There is the line to the fuel pump, a line from the fuel separator to the charcoal canister (which, it appears) was removed, a line from the canister to either the carburetor air horn, or the air cleaner, and a vacuum line that signals the canister that the engine is running so that the fuel vapors can be drawn from the charcoal inside that canister. There is also a recirculation line from the fuel pump to the tank, if equipped with A/C. This allows for fuel return to keep the pump cool and minimize vapor lock.

This emission system in no way affects how the vehicle performs, so removing has zero benefit.

04-13-2017, 03:35 PM	#1
just_ridin Registered User Join Date: Jul 2016 Location: Mooresville Posts: 29	Fuel issues: lines plugged and smell in cab Hey guys...picked up a '72 beauty for cheap in Atlanta! the more you look the more is wrong with her, of course, but she's purdy as heck. Fuel stench in the cab. Obviously a new tank with EEC. There are 3 lines coming off the fuel tank and routing under the cab to the engine bay, two are plugged. Wondering a few things here, input would be appreciated. 1) where should the 3 lines be heading in the first place that all's running ok with two of them plugged? 2) Any venting issues or reasons for the smell to be in there so strongly with new tank/sending unit other than a bad seal/gasket on the sending unit? new sending unit along with the fuel tank, finally getting the seat out to have a look at everything and see if the moron who was in charge didn't get the seal right on the sending unit (hopefully simple cause for the stench). Really hoping for answers on the 3 lines/2 plugged bit. thanks!! Attached Images

04-13-2017, 05:41 PM	#3
just_ridin Registered User Join Date: Jul 2016 Location: Mooresville Posts: 29	Re: Fuel issues: lines plugged and smell in cab OK...so on the '72 there's a line to the fuel pump and a return line if you're running fuel injection...what's the third one for?

04-13-2017, 06:44 PM	#4
Steeveedee Who Changed This? Join Date: Jan 2013 Location: Simi Valley, CA Posts: 10,287	Re: Fuel issues: lines plugged and smell in cab There is the line to the fuel pump, a line from the fuel separator to the charcoal canister (which, it appears) was removed, a line from the canister to either the carburetor air horn, or the air cleaner, and a vacuum line that signals the canister that the engine is running so that the fuel vapors can be drawn from the charcoal inside that canister. There is also a recirculation line from the fuel pump to the tank, if equipped with A/C. This allows for fuel return to keep the pump cool and minimize vapor lock. This emission system in no way affects how the vehicle performs, so removing has zero benefit. __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA



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