My gas tank is creating a strong vacuum which within 3 mins of running, tries to suck air into the gas tank through the gas cap vent. It is a very loud whistling noise. Removing the cap instantly relieves the pressure and the gas gauge shoots up 1/4 tank. I'm trying to troubleshoot this and while many said the canister may be clogged, to me that doesn't make sense since the tank doesn't have an excess amount of pressure (it has the opposite). I have a feeling there is a clog in the line leading back to the gas tank or a tube that lets air into the tank or a failed electrical valve which controls returning air. I just have no idea where these are or where to start looking.
Forgot to include that the car has 102K miles and has the following stored codes (not-active): P0443 and c0131. I've also been getting the "Check gas CapForgot to include that the car has 102K miles and has the following stored codes (not-active): P0443 and c0131. I've also been getting the "Check gas Cap
message since 15K miles and have gone through 5 different caps. This last one now is aftermarket.message since 15K miles and have gone through 5 different caps. This last one now is aftermarket.
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Yes, you can't fill an AC unit by guesswork. You also need the specified amount of compressor oil if you replace the compressor itself. This is how it's done. First you pressurize the system with inert nitrogen gas and check for leaks. Then you use a recovery pump to suck out all the gas into a recovery tanks until you have a strong vacuum. Then you put the gas bottle onto a subtractive scale. You open the valves on the gauges and run the engine. As the gas leaves the scale, it add UP on the scale in Grams or Ounces. Always add as a gas, don't turn the tank upside down to add liquid gas as it will hydro-lock the compressor. The EXACT weight of gas is specified for that vehicle. It has to be right within a couple of grams. Not enough gas and it doesn't vaporize in the evaporator, (that part that turns liquid to gas and created cold. If there is too much gas, it damages the compressor and there is no room for the gas to vaporize, because the system is full of liquid gas on both the high side and the low side of the compressor.
i don't know but when mine did that, i left my gas cap loose untill i had it looked at. if not damaged too much, compressed air might pop it back in shape. be very careful and let someone experienced with this look at your vehicle.
When a car will not run right after refueling, it is usually the vent valve, that vents the tank.
If not opening, then using a small amount of gas will create a very strong vacuum, and not allow the car to run.
Try cracking the gas cap a little, to let air in and reduce the vacuum. Automotive Evaporative Emissions Part One
It could be a partial vacuum in the tank. Everything is obviously working properly - fuel pump and injectors.
Fuel tanks have an atmospheric vent - it's either a tub which vents to atmosphere or is inbuilt within the fuel filler cap - a small hole covered by a rubber seal.
If the vent isn't working properly air cannot enter the tank and the fuel level is 'held up' by the partial vacuum that develops as the fuel level drops.
Try running your vehicle with the gas cap loose - see if that makes any difference.
With a new electric fuel pump you'd expect -obviously - fuel to spurt out at the carb end.
The fact that no fuel gets through or it's intermittent tends to suggest a problem with the fuel line itself. Is it rubber? It may have collapsed /perished internally.
You may have a blockage at the fuel pick up point within the tank itself. I think this is probably the most likely .. something 'drifting' around the bottom of the tank and acting like a shut off valve..
If your tank is developing a vacuum it will cause problems. There should be a vent from the tank to atmosphere - either a thin breather tube or a flap in the fuel cap. If the breather becomes blocked a vacuum is caused in the tank - it 'holds up' the fuel.
If you can hear air rushing into the tank when you remove the gas cap - you have a vacuum. try removing the cap to see if it makes any difference
Sounds like it could be a fuel pump or a fuel pressure regulator depending on the engine you have. Usually when it takes more than a second or two of turning it over before it will start means the fuel is going back down the line when not running. This can be because of a leak, not fuel leaking out but air leaking in, the fuel system or it can be as easy and a gas cap not properly venting/letting air into the tank as the tank empties. If it doesn"t let air in the tank, then the fuel that is being pumped out is creating a vaccum and sucking the fuel back into the tank when you shut the car off. Try opening the gas cap and letting some air get in just before you shut the car off. Then if it fires right up next time you know you need to replace the gas cap. If not check for vaccum leaks around the intake. Good luck.
Yes in a cars fuel system ice can certainly cause problems. If the tank can not vent properly and ends up drawing a better vacuum than the fuel pump is capable of over coming due to fuel useage and the resulting vacuum created due to the drop in fuel level, then your car will just stop running due to fuel starvation. If there is a venting problem you would hear the air passing into your tank as your removed the cap. If anything it should be slightly pressurized vs having a vacuum in it.
Forgot to include that the car has 102K miles and has the following stored codes (not-active): P0443 and c0131. I've also been getting the "Check gas Cap
message since 15K miles and have gone through 5 different caps. This last one now is aftermarket.
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