Installed new delphi fuel pump and fram fuel filter. still no pressure on fuel rail valve and wont start. 2003 Chevrolet Tahoe
About 2 months ago my fuel pump went out. It died on me and i pressed the valve stem on the fuel rail and had no pressure so i dropped the tank and changed the fuel pump. soon as i did that i went back under the hood with the key on and it shot fuel out the stem and it started right up. drove it for a day and died again. pressed stem again and no pressure from pump. so i just changed it for a second time this time i changed it and the fuel filter thinking that was the problem. went under hood pressed stem and no pressure tried to start turns over and almost starts but just wont. what else can
Experienced mechanics share their insights in answering this question :
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.
How to Identify and Fix Common car Problems ?
Our sources include academic articles, blog posts, and personal essays from experienced mechanics :
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.
These include a bad fuel pump relay or control module, a blown fuse, a wiring fault, loose or corroded wiring connector at the pump, or even an issue with the anti-theft system. Until these other possibilities have been checked out and eliminated, the fuel pump should be the last thing that`s replaced.
The most common sign of a clogged fuel filter is trouble starting the car, since it depletes the oil supply going to the engine. Although a dirty fuel filter leads to ignition difficulty, a fully-clogged filter will fail completely, and the engine won`t start at all.
Weak or Corroded Fuel Pump.
If the fuel pump in your car goes bad, gas won`t be able to flow from the tank to the engine, and it simply won`t be able to run on its own. So we`ll simply recommend that you have the pump replaced.
Air pockets: When the fuel filter is replaced, it can create air pockets in the fuel system, which can prevent the engine from starting. To fix this, the air pockets need to be removed by bleeding the fuel system or using a priming pump.
Another symptom of a faulty fuel pump relay is an engine that does not start. If the fuel pump relay fails the fuel pump will be left without power. The engine may still crank when the key is turned, however it will not be able to start due to lack of fuel.
After the new fuel filter is installed, reconnect the negative terminal on your car battery, and reattach the fuel pump fuse/relay. Start your engine and let it run for a few minutes, checking to make sure that no fuel is leaking from your system.
The fuel pump shut-off switch has a red reset button on top of it.
The ignition circuit, which includes the ignition switch, controls power to many components, including the fuel pump and relay.
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.
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.
Press and hold the “Trip/Odo” button again until the Odometer says “1.” This means that the reset process has begun. Keep holding the button down while the fuel gauge resets. Release the “Trip/Odo” button once the reset is complete. You`ll know the process is finished when the Odometer display moves back to normal.
The top reasons for fuel pump failure are contamination, overheating, and the gears in the the fuel pump wearing out over time. Rust, debris, and dirt are three common particles that can somehow enter the gas tank and be fed towards or through the intank fuel filter and possibly into the fuel pump.
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 top reasons for fuel pump failure are contamination, overheating, and the gears in the the fuel pump wearing out over time. Rust, debris, and dirt are three common particles that can somehow enter the gas tank and be fed towards or through the intank fuel filter and possibly into the fuel pump.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
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.
Fuel pump not pumping gas. 1996 Chevrolet Blazer
ANSWER : Hey there, thanks for writing in about your 1996 Chevrolet Blazer. If you hear the pump, but still get no fuel out of the pump, then you have the power and ground backwards in the wiring or they have it backwards on the pump. If you need help having this checked, a certified professional from YourMechanic can inspect the starting issue and let you know what repairs are necessary.
I installed a new fuel pump on a 1997 dodge caravan, it turns on but no gas is getting to the engine. Access to the fuel filter is
ANSWER : Hi there. It sounds like the fuel filter being corroded is the issue. It will need to be removed as well as any lines that may be corroded. You may have to replace a good portion of the lines if there is a lot of corrosion. If the vehicle cannot be serviced where it is then fuel lines can be used but they need to be able to handle over 50 psi. You would be best to get some assistance from a certified mechanic, like one from YourMechanic, that can come to you to [replace the fuel filter and lines] https://www.yourmechanic.com/services/fuel-filter-replacement
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.
Fuel pressure
ANSWER : Hello,
You may want to try checking the fuel pump relay. The relay wires should have ground on two wires, power on one wire and switched power on another wire. To activate the fuel pump your ECU actually connects one of the ground wires to complete the circuit and send power to the fuel pump. If the wires all have power running through them, then it is likely you have a faulty relay. The wire coming from the fuel pump is the other ground wire. I would recommend having an expert from YourMechanic come to your location to diagnose your wiring as this can be very difficult and time consuming without the proper wiring diagram.
You may want to try checking the fuel pump relay. The relay wires should have ground on two wires, power on one wire and switched power on another wire. To activate the fuel pump your ECU actually connects one of the ground wires to complete the circuit and send power to the fuel pump. If the wires all have power running through them, then it is likely you have a faulty relay. The wire coming from the fuel pump is the other ground wire. I would recommend having an expert from YourMechanic come to your location to diagnose your wiring as this can be very difficult and time consuming without the proper wiring diagram.
Replaced fuel pump. Car won’t start. 2002 Infinity I35
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.
Changed battery and the fuel pump and car still slow to start. When it does start it shuts off without warning. Fuel filter is fine.
ANSWER : Hi there. The battery could be dead even though it has a full charge. There could be a dead cell or an over charged cell. Have the battery checked with a load tester. This will place a load on the battery and the battery is not to drop more than 3 volts during the test. If the battery drops more than 3 volts, then the battery needs replaced. Also, check the starter and ignition system for any faults. Look for corrosion on the ignition wires and see if the cables to the starter are loose. If you need further assistance with your no start situation, then seek out a professional, such as one from Your Mechanic, to help you.
Replaced alternator new, replaced fuel pump new, filter new, relay and regulator and it still will not start? Why?
ANSWER : If the car starts when you use a starting fluid as you say, then it’s clear your engine is not getting fuel. Fuel pressure is of course important, and is easy to test with the right equipment. I Know you have already replaced the fuel pump, but you still need to verify the pressure. The old 740’s depend on air entering the engine being measured by an air flow meter to determine injection quantity. Any air leaks in the intake will prevent the system from delivering sufficient fuel. So check the intake manifold and all the air hoses for anything that is damaged or not fitting well. Starting enrichment may be provided by a cold start valve, inconveniently located under the intake manifold, though that part was deleted right about the time your car was built, so it might not have one. If it does, it is controlled by a thermo-time switch at the top of the cylinder head (colored brown). If you get tired of trying to sort this out, you can contact Your Mechanic. They can send a technician to your home or office to check out your stubborn Volvo and let you know what can be done for it.
