Fuel pump running with car off

When I turn my car off (and pull the key out of the ignition) I can hear, what sound to me like the fuel pump kicking on for a few seconds then kicking off for :45 seconds to a minute then kicking back on again. This has been happening for a few days now. Local chevy place says it is normal but I am not buying it. This goes on the entire time the car is powered off. No other problems are present. No warning lights.

My car has 17650 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
Hello.

A fuel pump that stays on when the ignition is turned off can be caused by a few things. If you do not believe that the behavior is normal, then it may be possible that the the ignition switch or fuel pump relay have shorted and are feeding power to the pump. It may also be possible that a wiring short has occurred, causing the same issue. If the vehicle is new I would recommend taking it to a dealership to have them help you with the issue. Otherwise, a professional technician from YourMechanic can come to your home or office to diagnose the issue and replace the fuel pump relay or ignition switch if necessary.

Regards,

Eduardo
YourMechanic

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A fuel pump that stays on when the ignition is turned off can be caused by a few things. If you do not believe that the behavior is normal, then it may be possible that the the ignition switch or fuel pump relay have shorted and are feeding power to the pump.
when you switch the ignition on, the fuel pump situated inside the fuel tank starts pumping fuel to the engine. so yes, it DOES run even when the engine is off, when the ignition is on.
If you`re able to `cycle the pump` that typically indicates that the relay is not supplying power to the pump consistently – or the pressure regulator is starting to show signs of wearing out. It is also possible that the fuel filter is clogged with debris.
if it does not come on,check the fuel pump fuse and relay for power. if they are ok,don`t forget about the magic button(inertia switch tripped) if the truck has been bumped or hit in a wreck or hit pot hole in the road,the switch may have tripped,if so then push the red button down,so power will get to the fuel pump.
Once the car is on, you need to listen for the fuel pump. Someone else needs to turn the key because the fuel pump will hum for just two or three seconds if it`s working. If you do not hear anything, the pump is not working.
A simple method to check if a fuel pump is turning on is to listen for it. Open the fuel door, remove the fuel cap (if your car has one), and turn the car`s ignition to “On.” Put your ear next to the fuel door and listen for a humming noise. If you don`t hear any noticeable action, the pump is likely not working.
The fuel tank pressure sensor is part of the fuel pump assembly and is mounted on top of the tank or inside the tank. It`s part of the evaporative emissions system (commonly referred to as “EVAP”) and reads pressure in the fuel system to detect evaporative leaks, such as a loose or faulty gas cap.
Electronic Control Unit (ECU)

The ECU is the brain of the operation. It uses engine RPM and signals from different sensors to meter the fuel. It does this by telling the fuel injectors when and how long to fire. The ECU often controls other functions like the fuel pump and ignition timing.

Engine stalls

If the fuel pump relay has an issue while the vehicle is operating it will cut off power to the fuel pump, which will cause the engine to stall. A faulty relay may allow the vehicle to be restarted a short while later, while a completely failed relay will not.

Powered by the ignition and/or powertrain control module (PCM), the fuel pump relay`s main function is to provide the fuel pump with enough power. When the fuel pump relay isn`t working, then the fuel pump cannot either.
This usually lasts around two or three seconds, unless the ignition key is turned to crank the position. When the motor is cranking, and the key is in the crank position, the PCM will supply power to the fuel pump until the ignition key is no longer in the cranking position.
The fuel cut-off switch is a safety reset switch which starts the fuel pump and allows gas flow to the engine. If you get hit and it is only a minor fender-bender, the fuel pump may shut off; you will know when you try to start the car again and the engine just turns but doesn`t start.
The clicking means the relay is operating, but the pressure is built up, so it cuts off. The be signals again to come back into life. The fuel pump is not holding pressure when ign is on.
There is a reason gas pumps have an annoying habit of shutting off. Gas pump nozzles are designed with a device on the end that turn off the fuel flow when the gasoline runs back into it. This is a safety mechanism which prevents the gas from coming out and spilling when filling up the tank.
This usually lasts around two or three seconds, unless the ignition key is turned to crank the position. When the motor is cranking, and the key is in the crank position, the PCM will supply power to the fuel pump until the ignition key is no longer in the cranking position.

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Car only runs when jumper the fuel pump
ANSWER : Check to see if you are getting power when you test the green with orange stripe wire going to the fuel pump module. If you have no power then check the the fuel inertia switch, in the left kick panel, by the drivers foot, and see if the inertia switch is not tripped. If it is, reset it and the pump should work.

If the switch is okay then make sure it has power to it and from it, when cranking the engine. If you have no power then check the fuel relay and see if it has power to it and that it’s being turned on when you crank it. If you do not then you may have an issue with the computer not activating the fuel pump. This will require a scan of the system and in-depth tests further than the scope of what this diagnoses is capable of. You will need a wiring diagram to follow and a scanner to activate the relays to test the system.

If you decide to get this fixed, contact a certified mechanic who can perform all of these checks in order to find the root of your starting problem. Once this is done, an accurate repair can be made.

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I would recommend having a certified technician from YourMechanic diagnose this starting issue, get an accurate assessment of damage and cost estimate for repairs. YourMechanic.com can dispatch a mobile, professional mechanic to your location for this repair.

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ANSWER : Hi there – the metal component you describe is a fuel check valve on the fuel return line. Its function is to maintain a small amount of pressure in the fuel system so that starting does not require the fuel pump to run very long before the engine will start. Having replaced the fuel pump and fuel filter, I would check fuel pressure while the car is running. This is to check the fuel pump relay for burned contacts that won’t support full electrical current to the pump, and for proper fuel pressure – a malfunctioning fuel pressure regulator could also restrict power and higher speeds if pressure is too low. I would recommend an inspection of the fuel system by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

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ANSWER : You need to look at the theft light on dash to make sure it comes on and goes off when you turn the key to the on position. If light comes on and stays on then your theft system is causing the fuel pump to not be engaged. I recommend you check the theft system and then scan the computer for theft system codes. You may need to reprogram the keys to work or you have an bad sensor for the ignition key in the steering column.

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I have a truck that won’t run and is not getting gas to the engine. Fuel pump is running, have a new filter and new fuel pressure
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It sounds like you may have a clogged fuel injector or potentially a faulty injector that is fried internally. I would suggest testing them if you have access to a multi meter. Disconnect the injector from the electrical connector and set your multi meter to Ohms mode and measure the resistance of the injector. After testing all injectors, compare the resistance. They should be the same or very close. If they are not, they will likely need to be replaced.

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Not getting enough fuel car will not run right. It stalls when you give it gas and stalls when it’s running. It’s a 1984 Ford Escort.
ANSWER : Hi there, thanks for writing in. Several early 80’s Ford’s swapped from carburetor to fuel injected engines; including your ’84 Ford Escort. However, there were two different fuel systems available that year. If your Escort has the fuel injected engine, one item I’d check is the EGR valve or clean the throttle body.

Both systems impact fuel delivery into the engine and if they are dirty or clogged with excessive carbon build up, can starve the engine to create this type of issue. If it’s the carburetor version, the carburetor might need to be rebuilt, or may be an issue with float bowls inside the carb.

If you need assistance diagnosing the exact issue, feel free to contact one of our professional mechanics to complete an engine is stalling inspection firsthand at your own location.

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