FJ40 SNIPER EFI Fuel line Charcoal canister routing- is the cannister needed? (1 Viewer)

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Ive been reading up on the sniper efi set ups and will be moving in this direction. The 40 i picked up was missing some parts and running a weber with msd ignition so this conversion wont be like some of the ones ive been reading. I will be using a rear mounted blazer tank with an intank pump. I plan to run soft lines to the sniper as well as a return. The truck doesn't currently have a charcoal canister. Seems like some guys have left it out and others were recommending thats not a good idea. I feel like its necessary but not sure how its routed. Can someone give provide some knowledge on this please.
 
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Thecrazygreek responded to a PM and noted he bypassed the evap canister and the system works well. after reading more it looks like the evap releases air on fillup and allows air to enter as the fuel is consumed. Anyone else having issue without evap or recommend installing? Im leaning toward bypassing now but also want to make sure that if its advisable to have one that i do it now.
 
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Yeah well he’s wrong.

You absolutely need it and the entire evap system. Otherwise you are making a nice pressure bomb under your drivers seat.
Not only do you need it but you need a check valve. If you are using a Delco you can get a delco check valve and T it into the vacuum advance line. That way you are not sucking fumes into the the base of the a sniper at idle.
 
The PO of my 40 removed the evap stuff. He was running a single barrel Rochester carb with the stock semi transistorized ignition system. Both the fuel return line and vent line were capped. He also installed a VENTED fuel cap. Now the system worked...
but it reeked of that old car smell (gas vapors).

When I switched to EFI (TBI controlled using a Megasquirt) I added back the evap stuff. At first I just ran a ported vacuum line from the TBI to the charcoal canister. This turned on the evap system at any point off idle. Later I wired up a vsv solenoid controlled by the Megasquirt to turn on the evap system when the the car was above 160 degrees AND between 2000-3000rpm. Now i have no fuel smells at all.

Your call on the emissions stuff but I personally would never go back to how my 40 used to be. It just is so much more pleasant to drive.
 
Noted. I will be using a rear mount tank with an in tank pump. The T goes into the vacuum advance line between the distributor and ?.
Ive been looking up diagrams for the evap system and still not 100% sure on the routing. Is this the recommended routing-
fuel tank breather--- to Evap--- Evap breather- to purge valve.-- Also see one of the evap cannister lines tying into the PCV.
 
Thanks for the info. Im just trying to verify best practices. Im ok adding back in but want to know how to do so. The rig doesnt currently have an evap cannister or any of the emissions so not sure how to route correctly and what additional stuff i need to buy in addition to an evap cannister. i thought the system was somewhat passive ( not needing any solenoids)?
 
doing anything is worth doing it right the first time. Like in tank pumps, proper filter and proper evap/ charcoal canisters. One will regret and waste time if the complete system is not correct. I would find all the fsm info for your year, get the vapor sep parts and run a canister. Your tank will thank you.
 
Noted. I will be using a rear mount tank with an in tank pump. The T goes into the vacuum advance line between the distributor and ?.
Ive been looking up diagrams for the evap system and still not 100% sure on the routing. Is this the recommended routing-
fuel tank breather--- to Evap--- Evap breather- to purge valve.-- Also see one of the evap cannister lines tying into the PCV.

What kind of tank is it? Does it even have provisions for Evap? My LRA has them when I installed in my pig but some of the crappy plastic tanks don’t.

If you don’t have 3 small vent tubes on the tank then you won’t be able to hook it up like a 40 is normally run. I’m not familiar with a blazer tank.
 
Thanks for the insight. I think anything fuel related is not the place to cut corners i just didnt seem to read much info on peoples installs. I may have glossed over them as I was only prepping for the build thus far. I have pretty much all the stuff sorted out except for the evap/charcoal canister. Intank pump, 10 micron filter, an6 fittings, efi hose, manifold adapter,. last couple of pieces are the system itself and the adapter for the stock air cleaner.
 
its a 1994 s-10 blazer tank which will be rear mounted ( 20 gallon). Yes it has fuel supply, return and breather vent. Here is the pump

Screen Shot 2020-01-29 at 4.35.44 PM.png
 
Thanks Ill review your thread again. I did look at it a few times but its hard to pinpoint info when the threads get longer.
 
Thanks for the info. Im just trying to verify best practices. Im ok adding back in but want to know how to do so. The rig doesnt currently have an evap cannister or any of the emissions so not sure how to route correctly and what additional stuff i need to buy in addition to an evap cannister. i thought the system was somewhat passive ( not needing any solenoids)?

Earlier evap systems were passive. Generally just a ported vacuum source to the charcoal canisters purge line. Later evap systems incorporated thermovalves and later still solenoids to control when to purge the charcoal canister. I went with the latter system because it was easy to control using the Megasquirt. I am unsure of if the Sniper EFI has provisions for controlling relays/solenoids. Others can chime in on that one. The passive system works fine for our purposes.
 
Suprasoup- Thanks for the clarification. Id prefer the passive if given a choice and it is equally as effective.

So how did everyone else accomplish this? I don't think the megasquirt was used in most cases.
 

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PERFECT!!!!!!! Thats exactly what i was looking for. Thank you sir. I looked at a few Evap diagrams and it mentioned a purge but that makes life a lot more clear. so you run the tank vent directly to the canister and another line from the cannister to the sniper wth the check valve controlled by the vacuum on the distributor? The third port on the canister is capped on a desmogged?
 
PERFECT!!!!!!! Thats exactly what i was looking for. Thank you sir. I looked at a few Evap diagrams and it mentioned a purge but that makes life a lot more clear. so you run the tank vent directly to the canister and another line from the cannister to the sniper wth the check valve controlled by the vacuum on the distributor? The third port on the canister is capped on a desmogged?

Correct.
 
I just got this evap from my boys at @Cruiser Corps because the guy who pm’ed you the bad advice tossed the one on the truck that was “working well” that I’ve been reworking for almost a month.

8A98D32E-4FC5-4691-BC28-C5F7C1C9E3EB.jpeg
 
Most charcoal canisters have 3 ports. One port ( TANK) goes to your fuel tank vent line Another goes to your intake manifold (Purge). Purge requires a vacuum source. Either ported or manifold vacuum depending upon your application (passive or active control) The third is an air inlet port. This is left open to atmosphere. DO NOT cap this port.

What charcoal canister are you using?
 
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Suprasoup,
I dont have a canister at the moment. Ill probably get the Delco or the duralast one the guys use for the 80s. Noted on the air inlet. I was thinking the airinlet was on the bottom (fj40 version). I dont have one of the aftermarkets yet so not sure how its setup.

So are people still using the fuel separators as well? Im slightly confused on all the routing on there. i thought that was used between the tank and the canister. Why are their so many barbs? Sorry for all the questions. My 40 did not have any fuel related parts on it including tank, separator, evap cannister so i cant really decipher it by visual examination.
 

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