But if you did a vent to atmo line by the tank shouldn't that solve the gas tank groaning in the heat, or would it make the same sounds when the valve closes when cold and the tank wants to cool down? As in the reverse of when it gets hot and swells. After it gets hot, vents, cools but he valve is closed, and makes the tanks try to contract.

I'm about 90% sure the Hydra does, in fact, activate the solenoid to purge the charcoal canister. The Hydra pinout that I have shows it as 'A4' on the 'small blue' connector, connected to factory pin 3L, and it's 'PWM 11, User 10 - purge control'.

The logic to run it is pretty simple, IIRC it's basically open whenever there's vacuum and the engine's warmed up and the revs are in some range. It's not like the EGR where to make it work you need another set of 3d maps.

--Ian

That is true. I guess I never updated after finding that out. So yes the Hydra does use the evap stuff. No longer Hydra though, go all the MS things.

No issues with just yanking everything out yet. Looks good... so far. Just a datapoint.

I did like sixshooter and removed everything including the hard line and egr and all related solenoids as the hydra uses none of it. I just ran a hose down by the fuel filter with a lawn mower filter to keep bugs from crawling into it. It attaches to the tank where the char. cannister did. No issues with vapors.

Was this the actual, final result @flounder? What did you do with the big hoses that connected to the rear box?

I would remove all the evap stuff, both black boxes, all the lines, then plug the cap/rollover valve on top of the gas tank, the one feeding both charcoal cans.

If you just plug this or any other part of the purge system then the gas tank will hold mad pressure. Gas caps are designs to hold pressure, but they are easily fixed. I was even able to keep the rollover ball valve on my NA cap, just took the spring from the plunger so it's always venting.

So you're just venting through the cap- all old fashioned. Correct?
Any pictures of cap mod?

Yes, just out the cap. I didn't take any pictures, but there's a flat diaphram pushed closed by a spring, I just removed the spring, or the diaphram.

Na caps have three plastic tabs to push in, then the whole thing comes apart.

Delete the whole mess?
 

Does anyone have the answer to how to delete the whole mess of lines to the tank and both charcoal canisters (front and back? I have an NB1 and just want all of it gone the correct way

I just did this on my 2000. I capped the port from the mani to the from charcoal canister, removed the front canister, hoses, and hard line to the back of the car. In the rear, I removed the large charcoal canister and left the filter (~2" diameter canister with one hose on each end) and the vent (small plastic thing attached to the chassis where the hose ends).

Just connected the hose from the tank right to the bottom of the filter. No explosions yet, though I do notice faint gas smells on occasion. That makes sense considering what I removed.

Diagram in this post

In diagram, red means remove, green is jumpered together.
Don’t over-fill the tank or gas will run out of the vent.

DNM