bhuebs

Hi everyone,

I have a 2015 GS350 FSport and the last few times I've been pumping gas it will stop seconds after I start as if it is full. Sometimes it will get 3/4 full and do the same thing. It happens intermittently and at different gas stations. I have taken it to Lexus when it was still under full warranty, but of course they "failed to replicate it." when it happens I'm stuck filling my car at the slowest trickle I can with the pump (and sometimes even that gives the false shutoff)! Am I looking at an EVAC issue? Anyone have an idea whats going on or what I can do to fix this?

bclexus

The gasoline pump nozzle automatic shutoff feature is going to be slightly more sensitive on some pump nozzles, which can shut-off after only pumping gasoline for a mere few seconds if pumping at full force. It has nothing to do with your car's gas tank, fuel neck, nozzle bung or the EVAC system. The opposite can also happen - when filling the tank the nozzle doesn't cutoff soon enough when full and gasoline splashes out all over the side of the car. The best thing to do is fill the tank using the first or second latch position instead of full force like you're making a pit stop. So what if it takes an extra 15-20 seconds to fill your tank...you still won't have enough time to clean your front windshield!

When pumping the gasoline at full force the air that is replaced with gasoline needs to escape from the tank which is why the fuel tank nozzle bung has one or more holes alongside where you insert the nozzle. The more gasoline flow you have (i.e. full force) the less room there is for the air to escape from the tank as the gasoline fills the tank.

BMWs are known to be full (almost all the way up the fuel neck) when the nozzle initially shuts off where you really can't add more than a few extra drops of gasoline, whereas other vehicles can take as much as an extra couple gallons of gas after the nozzle initially shuts off. I never can add more than one second's worth of additional gasoline.

swfla

iTrader: (1)

I have similar intermittent issue. 2016 ES350, 46k miles. I think the gas pump handle sensor may be the issue. Maybe even a California thing as we have stringent pollution rules. If I hold the handle in the "correct" position, it usually works fine. Put the handle on automatic latch and let it go, it will kick off. It could also be a combination of the car and a sensitive pump handle. If your car is the issue, it's probably the air flow out of the gas tank is restricted. If there's a charcoal canister on your car, maybe it's damaged, defective since the car was new. Do you want to take a gamble and pay a mechanic to replace that part? Even if you took a tech from Lexus to the gas pump and showed him, they tend to rely on the computer to say if and what the problem is. Sometimes issues can't be pinpointed with guaranteed fix. Hope someone comes up with a better guess for you.

er34

I found that when gas stations underground tanks are near empty, the pump nozzle also has a tendency to shut off prematurely. When this happens, you should go to another station - you don't want the sediments at the bottom of their tank. There is also going to be higher chance of water condensate when the underground tanks are near empty - also bad.

swfla

iTrader: (1)

I was a manager at a fuel station for quite a few years. The way the fuel pickup in any tank is designed, it's close to impossible (under normal circumstances) to dispense fuel with water and sediment in it. There are also filters to keep the fuel clean. Once, we had 3 days of rain and water got into one tank and it made it out of the pump. Turns out the latest delivery person didn't properly close and latch the water tight fuel cap after delivering fuel. Rain water collected in a large puddle above this cap and allowed a lot of rain into the tank. Fuel tanks are checked with a dip stick and water indicator applied to the stick as normal maintenance. The pick up tube inside the tank is about 12" above the bottom of the tank. Water is heavier than gas, so any water lays in the bottom of the tank. When (and it does) it accumulates to over 4"(our policy), it gets pumped out with a special external pump by a mechanic. Plenty of stories out there about water in car tanks but they're mostly urban myths.

bclexus

I'm glad you snuffed out those myths.

My suggestion is to always purchase Top Tier gasoline from large volume stations and you'll never have a problem with gasoline.

er34

From what you described, it very much depends on how closely the fuel delivery workers and station attendants actually follow policies and do the regular maintenance/checks. Whenever you rely on humans to do something(particularly min-wage workers who just don't give a damn), it's a recipe for things to go wrong.

It's not necessarily just rain water either. The ethanol in our fuels are prone to absorbing water vapors in the underground tanks, which happens particularly for stations which are low traffic and don't get fuel deliveries for several weeks at a time. Over many cycles, this causes the fuel to degrade. Again, I agree these are thing that can be mitigated with established procedures - provided people follow them.

bhuebs

Thanks BC, but I did not mention in my original post that I start by only going one latch position in on the fuel pump handle. Even doing that from the start I will get the shut off. Then I resort to the manual hold where I'm pumping at the speed of gas just beginning to flow as you barely pull the trigger. I have had this problem from Chevron to Costco. It's not the end of the world but it still doesn't seem right to me!

bclexus

I forgot how your pump nozzles are configured, but if your gas pump handle can still be activated not inserting the nozzle all the way in, just back the fuel nozzle out of the filler tube just a little bit.

thallium

I've read that it can be bad to overfill the tank because you run the risk of saturating the filter that sends gas fumes to the intake (can't remember what the actual system and parts are called - evap?), which can cause rough running engine after filling up or might even damage the sensor which might make it hard to even start the car. I think the Lexus manual even warns about this.

My brother's Impala starting having this problem where it would not start after filling up with gas. He had to crank it over and over to get it to start, then once it did, it started fine until he filled up with gas again. He got it fixed and it was something to do with that system.

bclexus

I always fill the tank neck with gasoline. I can sometimes see the gas right at the tippy top, and I wonder if I can screw the cap on without it spilling. I have only overfilled one time thus far. Knock on wood!

Me knocking on wood...

mikha619

iTrader: (1)

Im having this same exact issue on my 2017 GS. I pump primarily at Costco and it prematurely cuts off when its latched in or when i manually am holding it in. I hope someone can figure this out! I cant figure out what to do myself.

bclexus

Have you tried not putting the nozzle in all the way when pumping gas?

azipod

I don't think it's a problem with your car. I experience this with A LOT of pumps at my favorite gas station. So much that I've resorted to only using certain pumps that I know will work on my car.

There is a solution, however. Before you put the male filler into your gas receptacle, use two fingers on your free hand to pull back on the big O-sleeve that goes around the male filler. You know you are doing this right when you can actually "hear" the gasoline filling through the tank. This method tricks the pump into thinking that everything is OK, and will continue to fill your tank until you are really full. I don't really know how to explain this in more detail. Another way is that you can use a pen instead of your fingers to hold the O-sleeve back. Trust me, your fingers will get tired!

I worked at a gas station during my teens and this is what we did during premature pump stops. Still works today. Gas station pumping machines haven't changed that much over the last few decades, I suppose.

ItzFilyO

Glad I'm not the only one with this problem. Always cussing at Costco's pumps because of this!