the vent line from the gas tank goes directly to the canister, its the small line.

the big line comes from the engine/purge valve. i would expect fluid to be coming from this line, but i usually just leave the whole system stock, so i don't have these problems

 

yea, I am going to try to find a picture of a stock system that way I can recreate it.

I was hoping for an easier way.

Thanks for your help.

Rob R.

 

I'm almost positive that I need to replace my check-and-cut valve, but have had no luck finding a replacement. Anyone know a source for them, or alternatively, how to build something that serves the same purpose from one-way valves or other fittings? Are they disassembleable?

It looks like it'd be a one-way check valve from atmospheric into the tank, and a one-way valve from the tank towards the charcoal canister. This wouldn't help in the event of a roll-over, but seems like it'd serve the purpose for emissions control

 

FB01-42-910A is the Mazda part number, every FC uses the same one, list price is $68, so if you get any discount it'll be much cheaper

 

Anyone have a picture of the location and how to access the check valve?

Thanks

 

you are all over on this lol

the valve is located on top of the fuel tank, I dont think its at all accessible without dropping the tank down

 

Opening thisnold thread, Im In the process of removing the factory supply and return fuel lines, It looks like the return from the charcoal canister runs to the check and cut valve, which sits just in front of the gas tank bolted to the chassis. As I am eliminating the charcoal canister, is it ok to remove this line and simply leave the nipple the check and cut valve open to the atmosphere, or is this valve not necessary at all anymore if the factory emissions control system is removed?

 

Breathing new life into this old thread instead of starting a new one...

I will occasionally smell some gas fumes when I drive my car, but lately it has gotten worse. Today it is warm outside but not really hot and I went for a long drive, and the gas fume smell was really bad. Additionally, sometimes when I drive the car on warmer days, like today, when I shut it off I can hear a noise coming from the gas tank area, like a low hum sort of, but if I crack the gas cap I can hear the pressure equalize and the noise stops. From reading this thread it kind of sounds like the check and cut valve might be bad, or maybe that and /or the charcoal canister. Only other possible factor for me is that I have an aftermarket (Autozone) gas cap.

I want to fix this so the gas smell goes away, and the tank is correctly pressurized. I plan to inspect the check and cut valve, but it looks like it is no longer available. Does anyone have a source for that?

Is it possible that the non-OEM gas cap could be contributing to this issue?

Any other ideas on things to look at?

 

Check and cut valve stays closed unless you flip over.

What you will want to check first is that the evaporator/vent line running from your fuel pump to your charcoal canister is unobstructed. I replaced mine back in 2014 because the tank would pressure and the line was rusted shut so no vapors could pass to the charcoal canister. If you have the charcoal canister evap system removed, you'll be getting same issues.

See if you can blow air through yours. If not, you can create a replacement line with some brake line tubing and a cheap hand bender.

 

Thanks. I will check the line for clogs.

There seems to be some confusion on what the check and cut (3-way check valve in the diagram above) does. Other reading I've done on the forum says it is the valve that directs pressure to the charcoal canister, or lets in air in the case if vacuum in the tank.

 

i run an "aftermarket" vented cap on my car, we also welded over all the old holes it no longer retains any of the stock fuel or venting system (except the pump cradle and sender)