I changed fuel pump and truck ran great for 3 days. Now after 3 days truck dies. It will start runs few min then dies like before
Ok changed fuel pump because truck would start right up then dies after couple seconds. I drove it with new pump for 3 days and got stranded. Truck doing same thing as old pump. The three days it ran it ran with new pump it ran perfect. Now starts right up but starts running rough after few seconds then dies. I pulled bed back off and made sure wiring is good no black spots. Is there a relay somewhere besides the 4 prong one in fues box under hood?' Does fuel line have restriction maybe?. I have new 2nd new pump coming tomorrow. I pulled air filter and truck died immediately. When I turn
Experienced mechanics share their insights in answering this question :
Check the bottom of the fuel tank for sediment. Age and mileage could have accumulated a lot of it at the bottom of the tank. If you did not, check and change the fuel filter. Rule of thumb – replace the fuel filter any time you replace a fuel pump. Also, check the wiring for any chaffing on the fuel pump when you remove it. While your problem is kind of unique, I have seen many GM truck fuel tank baffle loosen over time, occasionally rubbing against the fuel pump can intermittently short it out and/or block the fuel pump pick up. To have this diagnosed, consider having a certified expert from YourMechanic inspect the stalling issue to have this corrected.
How to Identify and Fix Common car Problems ?
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If your car doesn`t start with a new fuel pump, chances are the fuel pump is either not hooked up right or is broken. Double check that the pump is correctly installed and all hose attachments are plugged in. Next, check for any blockages along the fuel line—this can also cause your car not to start.
The most common and obvious reason your car may start then die is the fuel shortage in your engine. This happens because there`s not enough fuel in the fuel rail, and there`s no fuel pressure to keep the engine alive. The reason isn`t always you forgetting to fill up your gas 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.
The fuel pump shut-off switch has a red reset button on top of it.
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. Just move the seat forward and pull back on the carpet or popping off the cover under the seat to access the switch.
The most common reason a pump fails is wear on the pump from improper lubrication or over-use. The best way to explain a failed fuel pump due to wear and tear is to explain what other reasons may have lead to a failed pump: Most fuel pumps are lubricated by the fuel in the tank itself.
Bad Sensors
One common culprit for this problem is the crankshaft position sensor, which measures the position and speed of the crankshaft. The computer uses the information from this sensor to know when to fire the spark plugs. If the sensor isn`t working, the spark plugs won`t fire, keeping the engine from starting.
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.
1. Turn the ignition switch to position `0`. 2. Press down the rubber reset button on the top of the inertia switch.
If your car`s fuel pump has gone bad—but hasn`t completely stopped working—you should still be able to start it by applying manual pressure, attaching a fuel pressure gauge, or making sure the engine receives consistent heat.
Faulty Fuel Pump Relay: The fuel pump relay controls the power supply to the fuel pump. If the relay is faulty, it can cause the fuel pump to run continuously even when the engine is turned off. Bad Fuel Pump Control Module: The fuel pump control module is responsible for regulating the fuel pump`s operation.
The only things that are likely to cause fuel not to return are either a failed fuel pressure regulator, or an obstruction in the fuel rail.
The ignition circuit, which includes the ignition switch, controls power to many components, including the fuel pump and relay.
A clogged fuel filter causes low fuel pressure that results in a lean fuel condition and engine misfire. This can result in poor fuel mileage, rough idling and possibly cause the check engine light to come on. Once that light is on, it`s time for a trip to the repair shop.
A Bad Crankshaft Position Sensor
The crankshaft position sensor monitors the position and rotational speeds of the crankshaft. Without the crank sensor, the engine control module (ECM) wouldn`t know when to fire the fuel injectors and ignite the spark plugs.
Why won`t my car start but I have power? If you attempt to start up your car but the engine won`t turn over and the dashboard lights up, then you most likely have an issue with your battery. You could have a damaged or corroded battery terminal, which is stopping the engine from starting up when you fully turn the key.
If your vehicle won`t start, it`s usually caused by a dying or dead battery, loose or corroded connection cables, a bad alternator or an issue with the starter. It can be hard to determine if you`re dealing with a battery or an alternator problem.
As a camshaft position sensor weakens, so does the data it transmits to the ECM. Eventually the data signal becomes so weak the ECM switches off fuel and spark delivery, and your engine will not start.
Common signs include the Check Engine Light coming on, the car not feeling right when running, and issues with starting the car.
It incorporates a 5 volt electronic sensor input to vary the speed of the fuel pump with the sensor input. This 5 volt input is typically tapped from a MAP Sensor used in contemporary electronic engine control computers.
When the key is turned on, the powertrain control module (PCM) closes the fuel pump relay, which activates the fuel pump for about three seconds to pressurize the fuel injectors.
The FPSC uses a frequency of on-off to drive the speed of the fuel pump. This is also referred to as PWM or “pulse width modulation” motor-drive control.
The Fuel Pump Driver Module controls the voltage delivered to a vehicle`s fuel pump. By controlling the voltage, the module maintains optimal fuel pressure and fuel delivery to the engine throughout its full operating range.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
I changed fuel pump and truck ran great for 3 days. Now after 3 days truck dies. It will start runs few min then dies like before
ANSWER : Check the bottom of the fuel tank for sediment. Age and mileage could have accumulated a lot of it at the bottom of the tank. If you did not, check and change the fuel filter. Rule of thumb – replace the fuel filter any time you replace a fuel pump. Also, check the wiring for any chaffing on the fuel pump when you remove it. While your problem is kind of unique, I have seen many GM truck fuel tank baffle loosen over time, occasionally rubbing against the fuel pump can intermittently short it out and/or block the fuel pump pick up. To have this diagnosed, consider having a certified expert from YourMechanic inspect the stalling issue to have this corrected.
I changed the fuel pump and truck ran great for 3 days. Now after 3 days, the truck dies. It will start running for a few minutes, then dies like before.
ANSWER : Hi there, thanks for writing in. I’d be happy to help. It sounds like you should disconnect the connector to the fuel pump and inspect it for any signs of getting hot. The female connections may be too loose on the fuel pump and lose contact after running and getting hot. If there are indeed any signs of problems, then I’d suggest replacing connector and adding dielectric lube to pins before installation. This should solve the problem, but if you continue to experience issues, feel free to reach out to us for help again.
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.
My truck died while driving. Now will start, but dies when I push brake. If I start in neutral, I can put in drive and go but dies – 2003 Ford F250
ANSWER : Hello – your symptoms suggest that once your cold start features are no longer needed – engine warming up – there is an air "leak" that ruins low speed running. Causes could be a leaking exhaust gas recirculation (EGR) valve, or leak in the air intake. A failing fuel pump relay (burned contacts) could cause similar behavior, contacts become hot, then won’t pass enough current to run the pump. Failing pump can also act this way – gets hot and fails. I recommend a starts, then dies inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.
Odometer has lines, won’t start unless I put fuel in the intake. The fuel pump keeps running and doesn’t shut off? Seems like the truck wants to start.
ANSWER : Hi there. From the description you have provided, you’ve replaced the fuel pressure regulator, the fuel pump never shuts off and puts fuel in the throttle body, it runs until the fuel is gone, and the odometer has lines instead of mileage. This would appear to be a fuel control problem and communication failure.
Some possibilities are that the PCM (Powertrain Control Module) has shorted internally causing the fuel pump relay to be commanded continuously on, injector driver circuits are inoperative, or failed communication to the IPC (Instrument Panel Cluster).
This all needs to be confirmed through diagnostic procedures. I recommend having your vehicle’s fuel pump never shuts off, truck won’t start condition be diagnosed and repaired by a certified technician, such as one from YourMechanic.
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
ANSWER : Hi There,
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.
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.
Cranks and runs rough have to keep foot in gas to keep running. Has new fuel pump and died while driving after pump was changed
ANSWER : Check fuel pressure. There are only three possible explanations: a fault in fuel supply (plugged filter, injectors, etc.); ignition system problems; and air induction including the idle air control valve, throttle position sensor, mass air flow sensor and vacuum leaks including the PCV and EGR systems. If obvious, and easy to check, possibilities do not reveal the fault, the recommended service to request is a rough running diagnostic and the responding certified mechanic will travel right to your location and get this diagnosed and resolved for you. It is also possible that diagnostic trouble codes have set and the mechanic will attempt to retrieve those using an appropriate scan tool. If you have further questions or concerns, do not hesitate to re-contact YourMechanic.
Runs fine for days then acts like running out of gas and then dies and try restart and runs then dies ,when I turn key on you hea
ANSWER : The fuel pump in the fuel tank is designed to have low pressure and high volume to feed the front fuel pump the right amount fuel. The front fuel pump supplies the engine with high pressure to the engine.
When you do not hear the pump run then the fuel pump is bad and should be replaced along with the relay. You should not have to replace the in tank pump if it is running. I’d suggest replacing the fuel filter as well.
I’d suggest getting this inspected by a qualified technician, such as one from YourMechanic, to diagnose your stalling issue and make the necessary repairs.
