Hi,
I have a 2007 Saturn Aura XE 3.5 V6.

I was having issues with a gas smell that was unbearable when the car was parked in the garage. I was told that the issue was with the gas pump possible a cracked elbow. The car ran perfectly and gassed up perfectly but I decided to replace the pump to get rid of the smell issue.

The pump was replaced without any issue and the car started and seemed to run perfect also the smell was finally gone.

I took the car to the gas station to add gas and noticed the pump kept turning off. I assumed the issue was with the gas pump so I moved to another pump, same issue. It would take about $1.00 worth of gas then turn off. So I added just enough to know that I had gas and took it out for a test drive. The car began to stall out. I slowly made it back to my house and when I removed the gas cap there was a large suction sound. I started the car again and test drove it again it ran fine until it seemed the engine became starved for gas. Again I removed the cap and got the suction sound.

I checked online and someone seemed to suggest that the issue may be the fuel pressure sensor. So I purchased a new pressure sensor dropped the tank again and replaced the sensor. I took it out for another test drive same issue. Took it to the gas station, again same pump shut off issue.

The car runs absolutely perfect until it gets starved for gas then starts to hesitate until I remove the gas cap to release the vacuum lock.

All the lines seem to be connected properly including the vent line that runs next to the filler hose.

At this point I don't know where to go from here.

Any help with what may be causing this problem would be greatly appreciated.

 

Is your service engine soon light on?
Does the gas gauge read properly?

When the gas pump keeps clicking off, it is usually a case of the EVAP vent being stuck closed when it should be open. As you add fuel to the tank, the air it displaces must have somewhere to go.

The vent valve opens and allows the tank vapors to go to the charcoal canister to be soaked up. When sufficient pressure is built up in this system, a different valve releases these vapors through the canister to the intake to be burned.

If the tank is between 3/4 and 1/4 full Connor the computer will close both of the aforementioned Purge and vent valves to seal the fuel system. The system pressure rises and the fuel pressure sensor in the tank monitors how quickly the pressure pleats off with the system closed. If it bleeds off too quickly then you get codes for EVAP system leaks.

The other common occurrence which causes problems is that the canister gets filled with liquid gasoline from overfilling the tank at the pump. The passages that are supposed to pass gas vapor start passing liquid gas instead. This prevents the vapors from leaving the gas tank during fueling and builds back pressure, causing the pump to click off.

Are you positive that the noise you hear at the gas cap is a vacuum and not a pressure release? Should be able to tell with your hand which way the air is flowing.

if it is indeed building up negative pressure, it sounds as though the pickup for the gas is not positioned properly within in the tank and that you are literally running the vehicle out of gas.

Or the fuel pump pickup is installed correctly but is not physically located where the OEM part was, causing you to have less usable gas than you think you do, therefore encouraging you to run out of gas.

Did you use GM parts or aftermarket? Don't know if it matters in this case but most Saturn's behave best with a OEM parts.

Are you sure that you have reconnected all of the EVAP solenoid wiring? This could easily account for misbehavior of the vent

 

The car actually pulls a vacuum on the tank and sees how fast it bleeds off. Sounds like something didn’t get plugged in when the tank went back in. Maybe the small harness going up to the fuel fill pipe, that is where the vent solenoid is on my car.

 

Hi,
The service engine soon light is not on. The gauge is having issues because the once the vacuum kicks in it has a hard time functioning. I don't know why the gas pump kicks off except that the tank seems vacuum locked. There is a bit over a quarter tank of gas because it is so difficult to add gas.

The pump I removed was not an original GM part but the car ran perfectly with it. I replaced it with another after market pump that may have been from the same manufacturer.

It is definitely vacuum that is sucked in when I remove the gas cap.

Again this car ran and pumped perfectly with the old pump and this issue started with the new pump. Everything was properly connected which I double checked when I has to replace the new sensor. The car will run perfectly right now until the vacuum gets to be to much.

Thanks

 

So the car will run fine with the gas cap off? Then something must have got damaged when the tank was removed. Maybe smashed a small line or banged a purge or vent solenoid. Something has changed in the evap part of the fuel system, the fuel to the engine part is probably fine If the car runs well without the cap.

 

Problem Description

The 2004-2010 Chevrolet Malibu has known issues with the EVAP system, a part of your emission control system.

The EVAP canister vent valve or valve solenoid wiring may fail causing illumination of the check engine light, setting code P0446, and problems filling the tank with fuel.

To correct the issue, the EVAP canister vent valve, solenoid, and wiring must be inspected. The most common fix is replacement of the wiring connector or replacement of the vent valve assembly.

(13 people reported this problem)

your car is the same as the seventh generation Malibu.

 

Sorry for the partial misdirect.

Andy. Are both the purge and vent closed and the vacuum pulled from elsewhere or is the purge valve left open and the vacuum pulled through that line?

 

There is a vacuum source valve near the engine and a vent near the fuel tank. The vent is open when the engine is off so the car can refuel. The source is only modulated open during an evap evaluation and closed the rest of the time. The vent closes during an evap test and I believe it opens to let the canister do its’ job during normal running. Got to go work now sorry.

 

Ok I’m back, false alarm. There are two solenoids in the system, one is the purge solenoid and it is in the front near the engine. It should have a fitting with a green cap near it for dealer testing. The other is the vent solenoid in the back near the fuel tank and or canister.
The purge solenoid is used for two different purposes and is pulse modulated on most cars. The main purpose is to pull fuel vapors into the engine from the carbon canister to be burned rather than drifting off into the atmosphere. The second purpose is to test the evap system integrity as required by OBD2.

Next is the vent solenoid and it is there to mainly test system integrity during the evap test. It is normally open to let you fill the tank by letting the air out as the fuel goes in. It also lets air into the system as the purge pulls fuel vapors from the canister. It closes to test system integrity during the evap system test. The evap test usually only runs when the air temp is above freezing and the fuel level is between 25 and 75%. It also only runs after a 8 hour cold soak and looks at the temp sensors and run time timers. Hot fuel gives off more vapors and the test needs cool fuel to test system pressure changes.

I bypassed the 8 hour cold soak timer on the last evap test I ran on Wednesday and it failed due to hot fuel and said there was a small system leak. I had large leak failure on a 2012 F150, they have a capless filler and it is always the fill tube flapper failure. I consider this truck repaired even though I could not get a good evap test. I discussed this with the assigned driver and he said he would let me know if the check engine light comes back. I have 8 or 9 of these trucks and has always been the fill tube causing the problem.

 

Thank you, Andy.
I never knew there was a vacuum source. Therefore I figured to would close both valves for the evap test and monitor the pressure sensor in the tank for the pressure not growing as expected.
On further consideration that will never work b c fuel will vaporize differently w temp and therefore you would never have a standard curve to compare it to. Plus if I have to type this much to explain it, it's too complicated for real life use.4
Pulling a vacuum significantly larger than the vapor pressure of the gas with the system sealed lets you ignore the gas vapor contribution, so what you see in the test is a reduction in vacuum at a rate that is larger than some pre-determined rate.

I always thought it was the vapor pressure in the system building up to a set positive pressure, then opening the purge valve and having engine vacuum pull fumes from the canister. Never thought the flow would be enough to pull a vacuum on the entire system, but a vacuum is a vacuum and if the purge valve is open long enough, that's what WOULD happen ---unless the vent opens to provide make-up air.

Thank you again for stating concisely what IS.
OP: Sorry for the threadjack but you seem to have left us