BOSS 357

iTrader: (1)

89 Firebird Formula TPI

I have removed my charcoal canister and plugged the vent line from the gas tank. I was using what I thought was a vented gas cap, only to find out that it is mere a pre-vent type cap that lets the woosh out before you remove the cap. Fuel spills down the side of the car, nasty mess.

I will not vent an open tube out around my car. I cannot find a true vented gas cap. I'd love to if anyone knows where to get one.

I think I need to find a way to hook the CC back up. The issue is the stock ECM is gone, hence I need a way to control the purge solenoid. By just looking at it, there is a 2 wire connector (GRN & PNK); my guess is I need to get 12v and a ground to it. Is this the case? Can I use can constant 12v or should it be switched? Perhaps a rocker switch to apply/remove ground to activate it?



Thank you,
Eric

BOSS 357

iTrader: (1)

Yup, 12v switched and green to ground. But who really wants manual control of the charcoal canister? There's gotta be a better way than this.

89FormulaRoth

iTrader: (1)

I'm curious about that myself. I was thinking that maybe a non solenoid canister and TVS to control it say from a '77 Vette. Would that work?

crazybird

I would also like a simpler canister. I like the idea of keeping it on the car. but the lines are so nasty and breaking. my old thunderbird has a two line set up....

amargari

iTrader: (1)

Older cars had charcoal canisters that didn't require a solenoid. You could go with one of those.

crazybird

can you tell me how you would hook up the old school can? i have a sucking vac lin on the back of the manifold and a non sucking one going to the tb!

darbysan

I think you would want to hook up the Charcoal Canister directly to the TB, not the manifold. Manifold vacuum would be a huge vacuum leak. I ran mine on my L69 carb'd engine this way for years. Look for a canister from a carb'd car, roughly '85. You definitely don't want to run a plugged vent line.

crazybird

so what do i do with the manifold line?

darbysan

If you keep the check valves that are just short of the canister, you may have to supply vacuum to that valve. It is designed to keep 2 psi pressure in the tank. Over 2 psi, it will allow flow to the canister. I think the vacuum opens that valve, and once the 2psi is exceeded you have flow. No vacuum might restrict flow.

crazybird

The check valves are the circular devices? I have one. So the line going to the rear of the manifold is the only line that is sucking air. I am really confused. I apologize. What exactly does the line coming from the TB do?

darbysan

The line from the manifold is providing a vacuum signal to open the check valves. No vacuum ( engine not running), check valve stays closed. The line from the TB provides a lower level of vacuum to pull the gas fumes off the canister. The charcoal will absorb and hold the gas fumes until they see a vacuum, and will release the gas molecules when under vacuum. If you put full vacuum to the canister (from the manifold), it would overpower the canister and you would wind up with a vacuum leak.

HTH

crazybird

Ok so I want the manifold line going to the check valve? which is the circular piece. Then I want the lower TB vac line going to the canister? Is this right? If so what hole with the TB line connect too? You rock man I am getting a visual finally. Thanks so much. The smell of gas is kiling me!

aremy10

iTrader: (3)

i have a 91 bird with a carb. i kept the canister in mine, it was set by my ecm to turn on once i went 5 miles per hour and up. so i just grounded the one wire and ran the 12 v to the ign. so when i start the car , the canister is open and working . i figure whats the difference, the only time im not goin over five miles an hour is at idle so why not just have it active all the time

crazybird

i wish i still had the wires to do it. my car has been hacked. i just want to run the lines like an old model car. they had 2 lines and it looked like a coffee can.

darbysan

I'm going off memory here, but IIRC, the lines going to/from the canister are two different sizes. I think it will be obvious once you get the canister which is which. They may even be marked in/out. Just can't remember. Also, I think the check valve will be needed from the old style car, for the vac connection.

crazybird

the holes are two different sizes. the problem is nothing is labeled and the hoses are all gone except for the hard lines coming from the tb and manifold.