72 K5 EFI upgrade & evap canister woes

[TheKorndog]

Hi all, been while since I have been on here. I have been searching on how to best tackle my EEC situation; it goes like this:

Ran new 3/8" send and return fuel lines to feed my GoEFI 4 600 system sitting on my 383. Looking at all the cool little nipples on the tank-which I retrofitted an in tank pump to feed the beast-Im figuring on how to best tackle these. Plug, or use as intended?

I am going to have this dude in my garage, and would rather not have the fuel smell both in my shop, or while out on joy-rides. I am making the last touches on anything I can on the chassis, ie fuel lines/brake lines/exhaust/205 seals/wiring harness/etc. I'd like to get the body at least set before snow flies; I have the original evap cannister lines, and trying to decide if it is worth the effort to put these bad-boys back in and run EEC.

What I am asking from all of your amazing minds is...
a. is the eec system worth it for a resto-mod weekend warrior?
b. if you converted your system to efi (and using the factory'ish tank), are you using eec, and how (as in modifications to simplify)?
c. If you are using eec, is there an improved system I can update in its place?

72 K5 4wd
383 small block w/goefi 4
4L60e w/goshift transmission control

Appreciate any input...if I can clarify anything, let me know.
K

Had this in the wrong section...oops

[Steeveedee]

I've not any EFI upgrades, but I would say that if the setup doesn't pressurize the tank, the EEC system can remain. You'd need to figure out where to put the vacuum like and the vent line. Some of them teed into the PCV circuit. If the canister has a bunch of fuel collected, that will cause a slightly richer condition, Would the EFI controller compensate for that?

[TheKorndog]

I am not sure that it would pressurize with a vented cap, but that's where I get hazy on this part. I will have to pick up a new canister, as I do not have that. Just the original lines that run across the rear cross member next to the gas tank.

The EFI system runs a single 02 sensor, so I am thinking it could account for the collection of fuel in the canister if that were an issue.

[SeventyOne]

Here's my set up if it helps:

Edelbrock ProFlo4 MPFI, Holley retrofit in-tank fuel pump with fuel return.

My evap system is all hooked up as normal at the rear/tank area. (tank to standpipe, etc) and connected to the steel line running up the the Evap Canister under the hood.

Only thing NOT hooked up is the canister to the engine. Fuel tank is vented but it all goes through the canister. no gas smell and the engine runs as it should.

I'd assume this would work for you as well.

[jaros44sr]

Originally Posted by SeventyOne

Here's my set up if it helps:

Edelbrock ProFlo4 MPFI, Holley retrofit in-tank fuel pump with fuel return.

My evap system is all hooked up as normal at the rear/tank area. (tank to standpipe, etc) and connected to the steel line running up the the Evap Canister under the hood.

Only thing NOT hooked up is the canister to the engine. Fuel tank is vented but it all goes through the canister. no gas smell and the engine runs as it should.

I'd assume this would work for you as well.

Gotta agree 71, I'm running a FAST XFI, choose that system because I can run multiple tunes, 1 blank for security and 1 for the street

I don't run an EEC circuit, but I did build catalyst converter in case it fails the tail pipe sniffers

I would install a rollover vent like a motor cycle

EEC does not have work in my area, just has to be there when he looks, so if you have your charcoal cannister in place he should be happy, if he crawls under your truck your screwed

Got pics?

My system is a TPI from a 85 corvette and Vortex heads

[jaros44sr]

16638385632847356919684836799497 by James Jaros, on Flickr

Just the over flow connected for fuel so far

[TheKorndog]

Originally Posted by jaros44sr

Gotta agree 71, I'm running a FAST XFI, choose that system because I can run multiple tunes, 1 blank for security and 1 for the street

I don't run an EEC circuit, but I did build catalyst converter in case it fails the tail pipe sniffers

I would install a rollover vent like a motor cycle

EEC does not have work in my area, just has to be there when he looks, so if you have your charcoal cannister in place he should be happy, if he crawls under your truck your screwed

Got pics?

My system is a TPI from a 85 corvette and Vortex heads

I don’t have emissions requirements where I’m at all, so it isn’t a matter of skirting those for me. I’d like to eliminate venting & vapor issues if at all possible. Thought about running a nylon line up to a charcoal canister or retrofitting one back near mid vehicle like how things are setup currently in GM vehicles.

[TheKorndog]

Originally Posted by jaros44sr

16638385632847356919684836799497 by James Jaros, on Flickr

Just the over flow connected for fuel so far

I’m guessing the other ports are plugged?

I’ve got to install the tank but I’m at the point now I’ve pained the thing and used a rubberized coating that isn’t drying…so back one step. Yay

[SeventyOne]

Originally Posted by TheKorndog

I don’t have emissions requirements where I’m at all, so it isn’t a matter of skirting those for me. I’d like to eliminate venting & vapor issues if at all possible. Thought about running a nylon line up to a charcoal canister or retrofitting one back near mid vehicle like how things are setup currently in GM vehicles.

If you want to avoid venting/vapor issues set it up like i did. Zero gas smell, tank fills up normally, and if there were a rollover event it wouldnt leak everywhere.

[JMac11]

I left the Evap hardline in place when I did my LS swap. The plan was to vent to the air cleaner box if I ever had gas fume issue. Never had any issues, did not use the hardline.

[MARKDTN]

I always leave the EVAP and canister purge when I do EFI. I do usually use 89-95 TBI truck charcoal canisters because they only have a line from the tank vent and a line to the canister purge solenoid. I've done Tuned Port on both an '83 K20 and '85 C10 with '87 TBI fuel tanks and also a '71 C10 with an S10 Blazer TBI tank.

[TheKorndog]

Originally Posted by JMac11

I left the Evap hardline in place when I did my LS swap. The plan was to vent to the air cleaner box if I ever had gas fume issue. Never had any issues, did not use the hardline.

I ripped everything out of the chassis and blasted it all down. I used the nicop feed & return lines. I’m thinking about running a nylon line from the tank venting system to a canister under the hood. I’d like to make it functional if I’m going to stuff it in there-
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[TheKorndog]

Originally Posted by MARKDTN

I always leave the EVAP and canister purge when I do EFI. I do usually use 89-95 TBI truck charcoal canisters because they only have a line from the tank vent and a line to the canister purge solenoid. I've done Tuned Port on both an '83 K20 and '85 C10 with '87 TBI fuel tanks and also a '71 C10 with an S10 Blazer TBI tank.

Those 89-95 canisters should be somewhat available. Most likely if I use one it’s going to have to be something close…thanks for giving me something I can look into. Didn’t even consider canisters from those years
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[87Skier]

I did an LS swap. Used the factory tank, bought a fuel pump mounting kit, cut a hole in the tank and put it in. I plugged the original fuel pickup and reused the original gauge sending unit.

I used all the other fuel tank vent lines to connect to the stand pipe that's behind the fuel filler pipe. I've got a line going to the canister, then a purge line to the engine.

I only have gas smell in my garage right after filling. One of my lines is a little leaky and I haven't figure out which one.

I used a canister from a 97 Suburban that MARKDTN mentioned. It fits in the factory bracket which is handy.

[Classic Bowties]

Originally Posted by TheKorndog

I am not sure that it would pressurize with a vented cap, but that's where I get hazy on this part. I will have to pick up a new canister, as I do not have that.

If working on a 72 model K/5 (per your thread title) the fuel fill cap should be a pressure vacuum (non-vented) gas cap, by design the tank doesn't vent through the filler cap in 72 on the blazers. If needing a correct 1972 fill cap, we have some 72 specific GM NOS stainless double ring "pressure vacuum" gas caps available in the below linked parts board f/s thread, am pretty sure that we have a 72 vapor canister and mounting bracket setup pulled ready to ship also. Have a look and let us know, Mel

http://67-72chevytrucks.com/vboard/s...d.php?t=837726
.

[TheKorndog]

Originally Posted by Classic Bowties

If working on a 72 model K/5 (per your thread title) the fuel fill cap should be a pressure vacuum (non-vented) gas cap, by design the tank doesn't vent through the filler cap in 72 on the blazers. If needing a correct 1972 fill cap, we have some 72 specific GM NOS stainless double ring "pressure vacuum" gas caps available in the below linked parts board f/s thread, am pretty sure that we have a 72 vapor canister and mounting bracket setup pulled ready to ship also. Have a look and let us know, Mel

http://67-72chevytrucks.com/vboard/s...d.php?t=837726
.

Appreciate it, I’ve got a canister and may possibly need the bracket. When I tore this beast apart I put all of it somewhere, but still not sure yet if I’ve lost that piece. Time will tell. I’ve got the cap and filler and all of that stuff. Mostly figuring out if I should be using the factory vent/emissions setup
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