I changed the fuel pump in my car thinking that it was the problem, but I’m still not getting power to my fuel pump.
I have a 1992 Audi Quattro 100 I replaced the fuel pump and I'm still not getting the fuel pump to work I've checked the relay and I've checked the fuses what could the problem be I'm not getting fuel from the fuel pump
My car has 155 miles.
My car has an automatic transmission.
Experienced mechanics share their insights in answering this question :
If there is access to a wiring diagram, you can disconnect the fuel pump harness and install a test light in between the power and ground circuits and turn the key to accessory or try to start the vehicle and if the test lamp lights up, the circuit is not the problem and you may have picked up a faulted new fuel pump. IF you can hear the fuel pump power up and there is no fuel pressure at the fuel rail, the fuel filter may be clogged. Consider hiring an experienced technician like one from YourMechanic who can come out for a closer inspection of the vehicle to run a few tests and offer a more personal diagnosis of your fuel system concerns.
How to Identify and Fix Common car Problems ?
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There are several reasons why your fuel pump may not be working after replacing it. The most likely reason is that it was not installed properly. Double-check that it is securely hooked up to all fuel lines and electrical wires. One common mistake people make is installing the pump upside down.
Electrical issues: Electrical faults are also significant contributors to fuel pump failures. The most common electrical issues are rusted connectors, loose connectors, or melted wiring and connectors.
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.
There`s no such thing as an intermittent mechanical fuel pump failure. Any power loss, engine `choke` problems, etc. are being caused by something else. In a fuel injected engine, electric fuel pumps can fail intermittently.
If your vehicle`s fuel pump cannot get gas from the tank to the engine, you will have trouble starting your car. The car will struggle to start and run because the pump cannot push enough gas through. A worn pump loses its pressure and the engine is being starved of gasoline.
Step 1: Turn the key to run position. Locate the reset button to the fuel pump shut off switch. Press and hold the reset button for about 20 seconds. Note: The fuel pump shut off switch reset button is usually located either under the dash in the driver compartment or under the driver or passenger seat.
The ignition switch will momentarily provide power to the fuel pump and ignition system when it is in the cranking position, which may allow the vehicle to start. However, if it has failed in the “on” position, it will cut off power to the fuel and ignition systems as soon as the key is moved back to the “on” position.
The throttle position sensor (TPS) is usually connected to the throttle plate shaft in the throttle body. The TPS reads the angle of the throttle valve and transmits an electrical signal to the PCM. The PCM uses this real-time signal to help calculate or modify fuel injector pulse width, controlling air/fuel mixture.
You can use one of the ME ECUs Slow/Relay Low Side (LS) drivers to drive the fuel pump. Note this must be done via an automotive four-pin relay as fuel pumps can draw 20+ Amps. If you do not have enough Relay Low Sides, then you can of course use a PWM Low Side instead.
A poor connection can cause enough resistance to lower the amount of voltage reaching the pump. This causes the pump to turn more slowly than it should, and can shorten the life of the pump. Replacing the vehicle side connector should solve the issues with poor connections, but sometimes causes another problem.
Once the vehicle determines the systems are safe, then the vehicle allows you to restart. The fuel pump shut-off switch is located behind an access panel on the right side of the luggage compartment. The fuel pump shut-off switch has a red reset button on top of it.
The switch will usually come with a reset button that will reactivate the fuel pump if the switch was tripped. The fuel pump switch is an electrical component, and just the same as the rest on the vehicle, over time it can wear out and develop issues.
Step 1: Turn the key to run position. Locate the reset button to the fuel pump shut off switch. Press and hold the reset button for about 20 seconds. Note: The fuel pump shut off switch reset button is usually located either under the dash in the driver compartment or under the driver or passenger seat.
If a fuel pump isn`t installed correctly, it either won`t work at all or won`t supply enough fuel to the engine. When the fuel pump isn`t working right, your engine isn`t getting the amount of fuel it needs to run well. Your engine loses power and fuel efficiency.
The fuel pump shut-off switch has a red reset button on top of it.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
I changed the fuel pump in my car thinking that it was the problem, but I’m still not getting power to my fuel pump.
ANSWER : If there is access to a wiring diagram, you can disconnect the fuel pump harness and install a test light in between the power and ground circuits and turn the key to accessory or try to start the vehicle and if the test lamp lights up, the circuit is not the problem and you may have picked up a faulted new fuel pump. IF you can hear the fuel pump power up and there is no fuel pressure at the fuel rail, the fuel filter may be clogged. Consider hiring an experienced technician like one from YourMechanic who can come out for a closer inspection of the vehicle to run a few tests and offer a more personal diagnosis of your fuel system concerns.
Just replaced my fuel pump but its not getting any power tested fuel pump relay and fuel fuse both good tested the wires all good.
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.
the car is acting like its getting to much fuel. changed the fuel pump, fuel filter, and the fuel pump relay.
ANSWER : There could be a few things contributing to your problem. You are correct that clogged or sticking fuel injectors and possibly the fuel pressure regulator could be faulty. A plugged catalytic converter can also cause the vehicle to bog down. A failing throttle position sensor can cause the symptoms you describe as well. I suggest having a certified technician, like one from YourMechanic.com, do a few tests to determine the exact cause of your starting concern.
When my car gets warm and I stop at a light or stop sign it shuts off only after car get warmed up I’ve changed a few things but
ANSWER : Hi There,
It sounds like you may have a failing ignition coil. The 15-20 minute gap in between when you are able to start your car sounds like something called heat cycling. This happens when ignition coils begin to fail due to excessive heat and shorting out. Ignition coils are coated with a varnish-like insulation that becomes brittle over time after being stretched then contracted repeatedly The insulation develops small fractures that open when heated and close when cooled. When open, they allow shorting of coil windings and decrease or eliminate the coil’s ability to function. This type of temperature cycling happens because every time you shut the engine off, the fan stops running, the coolant stops flowing and the temperature under the hood rises. Every time you start the engine again the coolant flows, the fans turn on, and the temperature drops. I would recommend having an expert from YourMechanic come to your location to take a look at your vehicle to properly diagnose your ignition system.
It sounds like you may have a failing ignition coil. The 15-20 minute gap in between when you are able to start your car sounds like something called heat cycling. This happens when ignition coils begin to fail due to excessive heat and shorting out. Ignition coils are coated with a varnish-like insulation that becomes brittle over time after being stretched then contracted repeatedly The insulation develops small fractures that open when heated and close when cooled. When open, they allow shorting of coil windings and decrease or eliminate the coil’s ability to function. This type of temperature cycling happens because every time you shut the engine off, the fan stops running, the coolant stops flowing and the temperature under the hood rises. Every time you start the engine again the coolant flows, the fans turn on, and the temperature drops. I would recommend having an expert from YourMechanic come to your location to take a look at your vehicle to properly diagnose your ignition system.
Car is not getting fuel. I changed fuel pump and checked the fuel pump relay. It was in good condition. What else could it be?
ANSWER : This may likely be related to the fuel pressure regulator. This is a unit that helps to maintain the fuel pressure in the system. When this is not working, this may cause an erratic fluctuation in the fuel pressure or in some cases, no fuel pressure at all. If you’d like assistance with this repair, I would recommend having an expert from YourMechanic come to your location to diagnose the issue firsthand and service your fuel pressure regulator as necessary.
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.
Installed new delphi fuel pump and fram fuel filter. still no pressure on fuel rail valve and wont start. 2003 Chevrolet Tahoe
ANSWER : Hi there – I suspect you have weak power getting to the fuel pump. I would first check the voltage coming out of the fuel pump relay. If the contacts in the relay are burned, you will not get reliable current flow to the pump. Check the fuel pump ground as well (voltage drop across the ground, not just continuity). I recommend a fuel system inspection performed 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.
Engine crank, no coil spark, fuel pump does not kick in.
ANSWER : Hi there. There could be multiple issues causing your lack of spark problem, ranging from a minor electrical short in the main relay to an issue with your ECU. In order to know for sure, you should have a professional mobile mechanic complete an electrical problems inspection.
