I have been wondering what to do with the fuel purge system. Anyone have a solution? I am trying to get on a Haltech BB, but it is not up and running right now.

 

are you talking the carbon canister for the fuel tank? could be routed to intake or to atmosphere.

 

Yeah, I'm talking about the charcol canister and the fuel purge solenoid that route the fumes into the intake for burning.

 

I'm thinking of running a pressure switch to control the solenoid. I would like to stay somewhat emissions friendly. If anyone has an idea please feel free to share. I'm also looking at some options for control the oil metering pump as well as getting one of the PCV Tech adapters. Anyone had good success with these?

 

Dump the fuel purge system, but you can keep the charcoal canister. I ran that way for a year and then ran without both for another year (really 6months, but is has been a year).

There are RPM based outputs on the Haltech, one is the Torque converter lockup. Most people use that for the airpump if they don't go electric.

 

So you just dump the charcol canister to the air? Can you smell it at all? I know the rotary exhaust can overwhelm every other smell, but I am just curious.

 

So, what have people been doing with the purge system since 2001? Right now I have it vented to atmosphere...with a full tank of gas, I can smell vapors.

Anyone know when the purge solenoid should vent the fumes into the intake? I'm sure we can program the haltech to do something similar to stock.

Also, I noticed when I open the tank (to fill with gas) it doesn't depressurize like it used to...pssssssssssssssssssssssssssshhht. I believe this is because the purge line is just venting to atmosphere.

any thoughts??

 

do you haltech guys just leave the line open? You have to do something with it! as of now my hard line is vented to air.

 

I'd try and run it into a constant vacuum source.
You can run a check valve in the line so it closes under boost, as the only constant vacuum souce is prior to the turbo.
Having it just vented will cause the car to smell of gas fumes at times.
Plugging everything up can cause headaches when filling gas from commercial gas pumps.


-Ted

 

Thanks Ted!

I was thinking about running it thru that black can thing, under the elbow, then thru the metal check valve into a nipple on the UIM.

any thoughts on why my gas tanks doesn't go pssssssssssssssssssssssssssshhht, when I take the cap off?

 

Are you running the stock vapor "recovery" system now?
Or is it just vented?
If it's vented, you'd get no pressure.

For a stock system, this is what happens...
Any pressurization goes through a check valve on top of the gas tank.
The pressure goes up to the front and terminates with the charcoal canister.
The canister is then purges and relieved when another fitting sees vacuum.
On a stock system, this fitting leads to a "T" that connects with the purge valve.
When the upper intake manifold sees vacuum, the purge valve opens and vapors from the charcoal canister and some of the "positive crankcase" vapors off the oil pan are ingested and burned in the engine.

How far empty do you run the gas tank before you fill up?
The more empty the gas tank is, the more "pfffffssssst" sound you get.


-Ted

 

Thanks again. I should have mentioned this was an FD...only for the fact I don't know what T you are referring to??? I don't think this system has to do with crankcase venting...95's don't even have a PCV, just a vaccum source from turbo intake.

This is how I have it set-up now...check valve on tank -> charcoal canister -> this back thing (under elbow) I'll have to look up the name/pic **-> metal check valve -> intake.

the only thing that is different is I'm not using a solenoid...Stock setup has a solenoid **
The solenoid is fed from the black thing (looks like a mini canister) and the output of the solenoid has a check valve before the intake.

Orignal thoughts, the solenoid is closed idling and cruising low rpms...for emission purposes???

 

pics show
canister
solenoid
metal check valve

 

Oops, sorry abou that - I assumed it was an FC.

Yeah, your set-up sounds fine - no smoking out the exhaust, right?

Yeah, I think the solenoid closes after a certain RPM level, cause it really only needs to open under cruise.


-Ted

 

yep, everything is in order now even got the pssssssssssssssssssssssssssshhht, before fill up this morning!

thanks for reading

 

okay...I'm thinking I need to add the solenoid valve back.

Anyone know when the solenoid is open?

I've read, it's open at idle and light cruising...and of course off.

When the motor is off and sitting, solenoid will keep fumes/vapors out of the manifold...some have experienced a boom noise when firing the car up. I have not. but have noticed my oil has a stronger fuel smell since hooking the purge up without the solenoid.

Anyone run the purge system?

Who thinks fumes/vapor can saturate my motor while it's sitting...making it's way passed seals and into my oil pan?

 

I've change the oil, and installed the solenoid back in*. Not a scent of gas in my oil. Correction to the above post...the solenoid is closed when the motor is off, I believe that was a typo.

I will wire the solenoid to open when the airpump is running.



*pretty slick where I've mounted it (I'll get a pic up sometime). It's mounted on one of the AWS BOPs...took one fastener out, (bracket on the solenoid has a stud) and screwed in the solenoid valve in.

 

good post

 

finally got around to wiring this thing in...here are a couple pics.


there is a pic of my harness unwrapped, and you can see the pigtail loops I added in so I can pass more wires thru the firewall connector (pic attach, for those who haven't seen it) with only splices.

there is a pic of the wires to be splice in the car also.

 

more info, for all the people with Haltech running emission equipment (I think it's just me, so I better jot it down so I don't forget )

solenoid voltage

idle - 12V
1100 - 3300; 4-10V

I used the wg map, and programmed the map to simulated this as close as possible.

I might try to switch to an rpm base map.