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I am trying to clear up as much real estate in the engine compartment, and this seems like a likely candidate for deletion. I am soon to be running an aftermarket standalone ECU, so it won't be able to control the purge solenoid anyway.

Anyone got any ideas?

take out canister and plug the lines. that's how we used to do it on old school hot rods

Just do a "U" on the in/out lines.

So run a line from where the hardline on the motor goes to the canister to the hardline that runs to the canister purge solenoid? Makes sense.

Really. What is this for? Any effect on performance???

Adam West wrote:Really. What is this for? Any effect on performance???

it shouldn't; it'll pull vapor from the fuel tank into the manifold but it shouldn't be enough to matter.

on our cars the purge solenoid is open when the car is above 3mph I believe; regardless of throttle position - personally I'm still running the N/A canister with a small vac one-way valve in the return line to the fuel tank to keep from pushing air into the tank when boosting.

It's an emissions-related device.

I don't think there would be any major benefits or detriments to removing it, except cleaning up the engine compartment and simplifying things.

I'm sure Vikash will disagree, but I look forward to his view of things.

You guys must be made of money and just love spending it on gas. The canister collects evaporated fuel from the tank and stores it for later introduction into the engine. Gasoline evaporates quite rapidly. In the old days, they vented it to the atmosphere which is stupid on at least three levels. You can plug the lines together and you'll likely be fine, but keep in mind that in warm weather you could be building up some decent fumes in the intake tract. You will also probably get a CEL (definitely on OBD II) and will have trouble passing inspection if you live in a civilized state.

What do you mean by 'building up some decent fumes in the intake tract'?

We don't have any inspections, so that's not a concern.

If you just run the 'in' and 'out' hoses together, the evaporated gasoline will find their way into the intake tract rather than being stored in charcoal until a valve and engine vacuum pull them out for use. This would be more a concern in hot weather and I'm not sure if it would cause an issue or not, but the possibility, however remote, is there for intake ignition of the gases. The ECU would probably learn around any issues of an unexpected richness at start up.

The canister purge solenoid should not be open when the car is sitting, so you shouldn't get any build up of gasoline vapor in the intake manifold, however when the solenoid does open, you could in theory have an in-rush of vapor. Whether that would cause any issues....I don't know.

scuzzy wrote:

Adam West wrote:Really. What is this for? Any effect on performance???

on our cars the purge solenoid is open when the car is above 3mph I believe; regardless of throttle position - personally I'm still running the N/A canister with a small vac one-way valve in the return line to the fuel tank to keep from pushing air into the tank when boosting.

The statement about the purge solenoid being open when the car is above 3mph is not correct. I'd have to look in the manuals for the details, but I believe it opens when throttle is above a certain point for a certain duration, typically during "cruising". The port where the purge solenoid connects to the throttle body has no vacuum when the throttle plate is closed, so I can't see the solenoid being open during that situation.

Oh, right! Dammit, I was thinking the valve was incorporated into the canister.

So the vapors would build up inside the tank, then. You wouldn't want to leave the car in the sun over a vacation, I would guess. The old cars had vented gas caps, but today's are pressurized. I suppose you could leave the cap partially open, but the risk, pollution, and cost in expensive evaporated gasoline would make that kind of a dumb solution. I'm pretty sure OBD I doesn't throw a code for it, though.

Legacy777 wrote:The statement about the purge solenoid being open when the car is above 3mph is not correct. I'd have to look in the manuals for the details, but I believe it opens when throttle is above a certain point for a certain duration, typically during "cruising". The port where the purge solenoid connects to the throttle body has no vacuum when the throttle plate is closed, so I can't see the solenoid being open during that situation.

Straight from my '91 FSM:

The ECU receives signals emitted from the water temp sensor, vehicle speed sensor and crank angle sensor to control the purge control solenoid.

The purge line is connected to the throttle chamber to purge fuel evaporation gas from the canister according to the amount of intake air.

Can anyone think of any reason not to simply plug both lines? Other than a possible build-up of pressure in the tank when the car is sitting for long periods of time in warm weather, I can't.

Plug it up? How to do? Chewing gum...a la McGiver????

AW

internetautomart wrote:take out canister and plug the lines. that's how we used to do it on old school hot rods

No. That won't allow any way for vapors to get out of the fuel tank. You don't want your tank pressurized.

douglas vincent wrote:Just do a "U" on the in/out lines.

You could give that a try; it may mess a little with air/fuel ratios sometimes, causing rough idling, but it may not be a big deal. On a turbo model, you actually have three lines. You could cap the auxiliary one and put a check valve in between the other two, or you could just connect the auxiliary line to the inlet line and cap the remaining one.

evolutionmovement wrote:In the old days, they vented it to the atmosphere which is stupid on at least three levels.

Right. If you do want to get rid of the system, though, the way to do it is to vent to the atmosphere. If you're okay with continuously venting expensive, carcinogenic, poisonous, and inflamable hydrocarbons to the air, that'll do the trick.

So your standalone ECU doesn't have a single spare solenoid control that you could use to drive the purge solenoid?

it may, but i haven't figured out how to do so yet.

it has several extra injector drivers that aren't in use that can be used for aux outputs, but I can't seem to find the options to use them as such.

IronMonkeyL255 wrote:it may, but i haven't figured out how to do so yet.

it has several extra injector drivers that aren't in use that can be used for aux outputs, but I can't seem to find the options to use them as such.

All you really need is a setpoint control...and my Perfect Power has those...so your Autronic has to...

I figured it out.

I just have only been messing with the software, so I can't really see what the changes I make do to the car.

I need to get some cash so I can get this thing installed.....

Legacy777 wrote:

scuzzy wrote:

Adam West wrote:Really. What is this for? Any effect on performance???

on our cars the purge solenoid is open when the car is above 3mph I believe; regardless of throttle position - personally I'm still running the N/A canister with a small vac one-way valve in the return line to the fuel tank to keep from pushing air into the tank when boosting.

The statement about the purge solenoid being open when the car is above 3mph is not correct. I'd have to look in the manuals for the details, but I believe it opens when throttle is above a certain point for a certain duration, typically during "cruising". The port where the purge solenoid connects to the throttle body has no vacuum when the throttle plate is closed, so I can't see the solenoid being open during that situation.

When using the scan tool on my ECU the purge solenoid opens regardless of throttle input and only when the car is rolling better than 3mph. I watched this very close several times. I don't know about your engine but my purge solenoid is connected to a vac line on the 3rd cylinder intake runner and is always exposed to vac and boost; I teed my recirc valve into this line and put a one-way vac check valve at the purge valve<->canister connection to keep air from flowing back towards the canister and into the fuel tank.

I dunno about you, but when I was digging around at all of this and fiddling with the lines with the engine running on a warm day, I got a very strong fuel vapor smell and decided to leave the system connected.

if you want to remove the canister and loop the lines you need to get a vented gas cap so the pressure can escape from the tank. Not doing so is very dangerous and will easily cause an explosion if the tank is compromised during a collision or there is a fire.

the better way (and more environmentally friendly way) to do it is to locate the canister in a place that you don't see (I usually put mine inside the fender, sometimes getting one from another car is needed to fit right) and use a check valve. Older cars had valves to control the purge before ecu controlled solenoids came to be popular. If you put a check valve (needed on boosted applications) to ensure you don't pressurize the canister during boost, and use one of these old staged valves or a small orifice to draw into the intake under vacuum you'll still have all the benefits of the emissions control, you won't have a pressurized gas tank, you won't have crap in your engine bay and you can still run your standalone.


Now make sure you keep your pcv there too if you're going on an emissions removal rampage, that's another topic though that I'm sure I've commented on before

scuzzy wrote:When using the scan tool on my ECU the purge solenoid opens regardless of throttle input and only when the car is rolling better than 3mph. I watched this very close several times. I don't know about your engine but my purge solenoid is connected to a vac line on the 3rd cylinder intake runner and is always exposed to vac and boost; I teed my recirc valve into this line and put a one-way vac check valve at the purge valve<->canister connection to keep air from flowing back towards the canister and into the fuel tank.

I dunno about you, but when I was digging around at all of this and fiddling with the lines with the engine running on a warm day, I got a very strong fuel vapor smell and decided to leave the system connected.

Hmm....sounds like yours is hooked up differently. That vac line on the 3rd cylinder intake runner is for the fuel pressure regulator. The purge solenoid sits right next to it though.

You can see in a couple of these pictures where the line ties into the vac line at the top of the throttle body.
http://www.main.experiencetherave.com/s ... injectors/
http://www.main.experiencetherave.com/s ... P_2466.JPG
http://www.main.experiencetherave.com/s ... P_2470.JPG
http://www.main.experiencetherave.com/s ... P_2471.JPG
http://www.main.experiencetherave.com/s ... P_2493.JPG
http://www.main.experiencetherave.com/s ... P_2501.JPG