solution for hooking up the canister with aftermarket carbs

Ok i finally found a solution to hooking up the vapor canister with my carbs,or any aftermarket carbs. as far as hooking up the purge on it,that can be hooked up with the factory controls, but the problem was venting the carb bowls and keeping the canister. A lot of people remove it, but we have a sealed fuel system, and those fuel vapors you smell are money evaporating from your gas tank. I finally found a vaccume operated fuel valve, as long as there is engine vaccume it remains open, when the engine shuts off it closes. I've seen these for up to a hundred bucks,but this looks like a low buck solution. what you would do is take the hose coming from your fuel bowl vent, run it to the carb fitting on the canister, now install a t fitting in that line, the outlet of the T goes to one side of this valve, the other end connects to your air cleaner. now when the engine is running,vacume opens the valve, and he carb bowls vent to the aircleaner, when the engine is off, the valve closes,and all vapors are absorbed by the canister,to be burned in the engine. the most complicated thing is hooking up the factory controls to make the purge work, but you can follow a factory diagram for that. here is the valve. http://www.ioffer.com/i/27264126 http://www.ioffer.com/img/item/918/732/26/a4af_1.JPG

Unfortunately, my fuel bowl just vents out through the air cleaner--Weber 38. I'm venting fuel into the atmosphere. The thing that bothers me the most about it is that it is costing me money.

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Originally Posted by mephi

Unfortunately, my fuel bowl just vents out through the air cleaner--Weber 38. I'm venting fuel into the atmosphere. The thing that bothers me the most about it is that it is costing me money.

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well i'm lucky enough to have external bowls on the SU's with a threaded fitting for each one. are you sure there's no way to externally vent the webber? no vent connection?

Nope...There is no fitting...just a hole that goes straight down to the float bowl. I'm going to stick an EFI charcoal canister on the thing today though. It'll keep me from venting the tank while I'm parked and the engine is off.

Here's a pic

http://i288.photobucket.com/albums/l...ke_kl/vent.jpg

Quote:

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Originally Posted by mephi

Nope...There is no fitting...just a hole that goes straight down to the float bowl. I'm going to stick an EFI charcoal canister on the thing today though. It'll keep me from venting the tank while I'm parked and the engine is off.

Here's a pic

http://i288.photobucket.com/albums/l...ke_kl/vent.jpg

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but you need air to go down that vent when the engine is running, if not you end up with vaccume lock and no fuel flows. to keep fuel evaporation down, the vent needs to close off when the engine is off and open when it's running. thats why i'm using the valve on mine, when there's vaccume, the valve allows air to vent the carb bowls and when the engine is off the valve closes and vapors go to the canister. to make the canister work right on this carb setup, you have to plumb it like an early evap system, these carbs have a signal port built into them,the keihin ones do, the system won't work without it unless you plumb it like an early system. I have all the emissions diagrams going back to the 70's, i think it's 80 or something that will work.

Can't really do anything about the float bowl was what I was trying to get at. I am however running the TANK vent line into the charcoal canister that I took off of the EFI Accord I junked. There is no carb vent line to worry about. I'll just loose fuel out of the bowl when the car is parked--or any other time. The odor of evaporating fuel follows me around. The tank will at least be sealed. Won't have to worry about that larger volume of fuel slowly disappearing on me.

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Originally Posted by mephi

Can't really do anything about the float bowl was what I was trying to get at. I am however running the TANK vent line into the charcoal canister that I took off of the EFI Accord I junked. There is no carb vent line to worry about. I'll just loose fuel out of the bowl when the car is parked--or any other time. The odor of evaporating fuel follows me around. The tank will at least be sealed. Won't have to worry about that larger volume of fuel slowly disappearing on me.

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how did you hook up the purge system? if you don't purge the canister it will saturate itself with fuel and eventually quit doing anything

right now I just have the vacuum line connected to the purge diaphragm and the vent line connected to the tank vent port on the cannister. I'm going to hook the purge line to something eventually, but I'll get to that after payday. Right now it just seals the tank while the engine is off if I understand the diagram correctly. When it is running, it vents.

Quote:

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Originally Posted by mephi

right now I just have the vacuum line connected to the purge diaphragm and the vent line connected to the tank vent port on the cannister. I'm going to hook the purge line to something eventually, but I'll get to that after payday. Right now it just seals the tank while the engine is off if I understand the diagram correctly. When it is running, it vents.

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well vaccume on the purge connection opens the valve,but it requires hooking it up to a manifold source to pull vaccume on the canister to purge the vapors,hence the complex system,this avoids a sudden rich mixture.

I was thinking that might be the case. I'm going to have to do some more diagram deciphering tonight. Until then, I will only slowly purge when the engine is on. If at all.