spottedfrog

Well Here is how I removed the Charcoal canister. Not sure if it is the best way. Should I have capped the float bowl vent instead of filtering it? I think Sterling fills in the vent? I can get a lumpy idle at 500 RPM. I'm sure the exhaust mani, 2 pre cats and main cat still on the car are hurting big time. I'm having a custom setup made but still researching
I used one of the valve caps for dirt bike gas tanks on the tank vent. This is all still experimental so if you have any ideas that might help that would be great.

orion84gsl

iTrader: (5)

That breather filter isn't going to do anything. The charcoal canister is there to act as a catalyst, which reacts with the fuel vapours to render them harmless and less blowupable. That filter isn't going to do anything but keep dirt out of the crankcase, which in it's own right is a good thing, but for your purpose, you might as well of taken the hose off and capped the remaining nipple.

spottedfrog

Thanks,
I'll cap the vent and switch the filter with the one on the crank case vent now. the one from the carb is smaller. Any thoughts on the motorcycle gas tank breather?

DivinDriver

iTrader: (15)

You've got to have some kind of vapor venting on the float bowls. Bad things happen otherwise.

spottedfrog

So keep the filter on the floats? what bad things happen with out venting? is there a better way than what I did?

spottedfrog

So it seems my float bowl filter may be redundant? am I correct that the floats vent into the air horn any way. so nothing "bad" should happen if I just cap it?

Also what could I do to smooth out the rough Idle at low idle idle seems to kinda pulse. But I can make it idle at 500rpm it still pulses if I move the speed up but not so much.

thanks

jinxed4dub

iTrader: (7)

The gas boils in the carb without the float vented. I believe.

blackdeath647

iTrader: (2)

i see good results as far as idle consistency goes every time i seafoam it (that's right, it has now become a verb)

DivinDriver

iTrader: (15)

Depends on what other mods have been made.

In the stock carb, the bowl vent solenoid opens the bowl vent to the carb throat while the engine is on. When engine is off, it closes the carb throat vent and directs venting to the charcoal canister instead.

"bad things"
Carbs operate based on air pressure differentials - - if you change the potential difference in air pressure between two areas of the carb, you change its behavior.

If the bowl isn't vented properly when the engine is running, the carb can't operate properly because there's no atmospheric reference pressure inside the bowls to properly drive fuel feed rates... pressure fluctuates as fuel is added and removed, which can cause surging, flooding, all kinds of unpredictable behavior.

If the bowl is not vented when the engine is shut down, vapor pressure from the fuel's natural evaporation (accelerated by the heat from the engine) builds up air pressure within the bowls, forcing fuel out thru the jets and flooding fuel into the engine while it is stopped. The problem here is twofold:

1) flooding a stopped engine makes it very hard to restart

2) excess fuel in the combustion chambers washes the residual oil off of the side plates, which increases oil-ring wear on startup (something Mazda identified as a problem early in the 7's life - - it's mentioned in the engine rebuild evaluation docs)

The idea behind the charcoal canister is to trap bowl and tank fuel vapors after shutdown (for emissions purposes), and then let them be sucked thru the engine when its running, so they can be burned up.

spottedfrog

Excellent information DrivenDriver.
that makes perfect since. My next question would be: aside from venting into the engine bay, what possible side affects would my set up cause?

I'm trying to decide if I should keep it like it is or go back to the canister.

cmanns

Why did you remove the charcoal canister ?

spottedfrog

Cmanns,
Less clutter in the engine bay. easier access to thing that are more important I couldn't thing of any reason not to. The fewer parts that are in there the less parts I have to work around or repair. I want a "sanitary bay"
I'm also thinking of making a premix tank to plumb the omp to and it opens up mounting locations.
Also going to as a fuel pressure regulator and upgrade fuel pump again more mount possibilities
just because I can.

DivinDriver

iTrader: (15)

I believe what Stirling does is to eliminate or disable the bowl vent solenoid so the bowls always vent into the carb throat, and then block off the vent tube since it's no longer used. That makes it very similar to older pre-emissions carbs where the bowls vented direct over the inlet - - you often see the slant-tipped vent tubes sticking up on older carb designs.

You'd want to check with him on that, though.

My only concern with venting gas fumes into the engine bay without containment would be a small but finite fire hazard.

That, and the environment aspect for those who are interested. I personally find individual mods to individual cars to be of infinitesimal impact; there's no way a single car by itself (or even 10,000 of them) even makes a measurable difference environmentally.

j9fd3s

iTrader: (3)

IMO....

1. charcoal cannister has no moving parts, takes zero power.

2. keeps the car from stinking like gas

3. could be mounted just about anywhere...

4. no air pump/acv + cats is just going to melt the cats.

spottedfrog

My charcoal can reeked of gas so the car doesn't smell any different than before. the cats are going away.

85TIIDEVIL

iTrader: (2)

Yes, Drivin... excellent description as to what the fuel bowl vent solenoid does.

I had mine act up some time back and was schooled as to what to do to fix the problem not why.