I've read through a few posts and still had some questions before I take the plunge and try replacing parts.

from what i understand, there's something wrong with the EVAP system, causing the sensor on the gas station's pump handle to shut off gas flow.
I can get a few squirts of fuel into the tank but usually after a gallon or 2 the neck will start filling.

• there are no codes thrown
• the car has been in this state for about 100 miles
• ive tried holding the pump at all different angles
• ive tried different pumps
• ive tried different pump rates

I've also tried disconnecting this line (pointing to it on the attached photo) on the charcoal canister while i pump to let it vent to atmosphere but to no avail.

Is there any other way I can temporarily bypass the system/mechanism that is preventing my refueling while I work on the proper solution? This is my daily driver and I currently have to drive within 1-2 gallons of range of a gas station at all times

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The following thread might help.
Gas Pump Shutting Off / Can't Fill Fuel Tank?

I’ve never torn apart a 3rd gen, so there may be way better info than I can provide. But I can at least explain operation and the same principles apply to all gasoline evaporative emissions equipped vehicles.

When you insert a fuel nozzle, and fill the tank, the air inside the tank needs to be displaced. Most of the time a valve is used that vent the air from the tank through the charcoal canister, only while pumping.

The rest of the time the tank is sealed to help prevent fumes from escaping to reduce hydrocarbon pollution. There’s usually a purge and vent valve in the system.

Most likely your issue is in the valve on the neck, or the vent valve. Again, this is a bit generic, but something is prevent your evaporate system from flowing air normally.

No. Filling the tank is completely passive. There is a vent line from the top of the tank to near the top of the fuel filler neck, above where fuel flows out of the nozzle.

This is the filler neck assembly in a 3rd gen:



One of those is blocked and needs to get cleared out...

Otherwise, the 3rd gen is pretty sensitive to fuel nozzle placement, especially on California vapor recovery nozzles. They must be put in the filler correctly and or it will auto-shut off (from the pump side) very often. The OP is in San Diego, so this could be contributing.

-Charlie

The vent doesn’t go through a charcoal filter? There’s no way… that’s the whole point of an evap system, is to catch fumes during filling and offgassing.

The evap system is only for fumes (excessive tank pressure caused by liquid gas turning into to vapor gas) when the vehicle is running. When you fill up the air you are displacing with gasoline comes back out the gas fill tube via that little tube attached to the larger fill tube. Some stricter states require gas stations to have fume recovery nozzles (California as an example).

EDIT: Newer vehicles have the EVAP system operate some checks while the vehicle isn't running, but fumes/air from filling the gas tank still don't interact with the evap system. If you have a bad evap purge valve you can experience hard starts after filling up because the gas vapor has made it's way into your intake and caused an unmetered extra fuel event (running way rich). Bad evap purge valve can also cause your vehicle to die while idling or driving for the same reason.

Exactly. The extra vent tube that runs along the main fill tube also supplies the 'signal' that the tank is full. When the fuel level in the tank hits the bottom of that tube, it sends a vapor pressure pulse up the filler neck which clicks the pump off.

-Charlie

The EVAP system in 2001 and 2002 4Runners can interact with fueling but not by design. If the tank is topped off, one of the EVAP lines can fill with fuel and start to saturate the charcoal as the cannister is lower than the fuel tank. 96-00 don't have this issue as it's much higher in the engine bay.

We had a 2020 Malibu in the shop last week that had to get the charcoal canister replaced and the evap lines blown out because the customer added an additional 2.5 gallons of gas because "I didn't want to have to stop for gas on my way to Dallas." The charcoal canister filled with gas and every time the purge valve was opened straight fuel from the charcoal canister was getting in the intake and flooding the engine to the point where it would die. Customer didn't understand that when the pump stops that you should stop as well lol

Good info guys. I just assumed that the 4runner had a neck valve like Subarus did.

Did you resolve this issue?

yeah, and dont laugh at me.

The tank was full >_<

My gauge at the time was broken, so I had to keep notes of my fill ups, and my lady had filled up the tank without telling me and without resetting the trip meter. What a nice thing that made me go crazy for a bit.

If your fuel level isn't working you might fall under the TSB, the 99' was the most effected, see VIN's.

EL010-00 Toyota Technical Service Bulletin

That was probably the best case scenario! We all have inaccurate gauges to some extent and the best thing you can do is keep using the trip odometer. I always use mine after almost running out of gas when it appeared that it had some. Now it flops to the E with 5 gallons in the tank so I don't trust it. Once I hit 225+ miles I am at a gas station.