Crank, No Start, replaced fuel and relay.
My truck shut off on me as I was driving, after it died I turned the key and it cranks over but does not start, so I figured it wasn't the battery or alternator. I only pulled one plug wire off and tested it and I have spark. I then did everything imaginable to test the pump and relay. It came out to be the pump. I replace the pump and filter and still no fuel and the pump doesn't even come on. I get a relay and still nothing. I then tested to see if I was getting power to the pump, at the harness coming out of the tank I put a meter on those wires and I'm only getting 8 volts so I
Experienced mechanics share their insights in answering this question :
When you applied power to test the pump directly, you may have had the power and ground backwards, and ran the pump backwards.
The pump connector that is only getting 8 volts should be replaced. The connectors are known to have a problem with voltage loss through the connectors due to corrosion. Replace the connector and it should fix your problem. Do not insert your big tester pin into the new connector or you may damage the female connector.
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.
Dead Engine
Finally, your vehicle might not start because of the battery, alternator, starter, fuel filter, or the fuel pump. All of these things play a role in getting your vehicle started. If the pump is dead, you won`t be able to get gas into the combustion chamber to start the car.
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.
Generally, a car cannot start without the main relay if its ignition system is electrically controlled. In this case, the vehicle won`t get any electrical signal in the fuel injector. As a result, it will fail to deliver fuel to the engine, and the car will make a cranking noise instead of starting.
The fuel pump shut-off switch has a red reset button on top of it.
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 basic operating system for an electric fuel pump is relatively simple. 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 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.
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.
The ignition circuit, which includes the ignition switch, controls power to many components, including the fuel pump and relay.
The starter motor requires considerable current, and the ignition switch cannot be controlled. If there is no relay, it will burn out. If the starting relay fails, the vehicle may not start.
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.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
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.
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Car sounds like its not getting fuel cranks normal. Fuel pump is working. Fuses and relays good. crank no start. No codes
ANSWER : Hi There,
Try starting the car and if it does not start, turn the key off and then pull one of the spark plugs out to see if it is wet with fuel. If the spark plug is dry, then you know you have a fuel supply problem. If the spark plug is wet with fuel, I would suggest next checking for spark issues such as a failed ignition coil. Ignition coils are prone to randomly failing and causing the car to not start without warning as you describe. I would suggest having a professional from YourMechanic come to your location to take a look at your vehicle.
Try starting the car and if it does not start, turn the key off and then pull one of the spark plugs out to see if it is wet with fuel. If the spark plug is dry, then you know you have a fuel supply problem. If the spark plug is wet with fuel, I would suggest next checking for spark issues such as a failed ignition coil. Ignition coils are prone to randomly failing and causing the car to not start without warning as you describe. I would suggest having a professional from YourMechanic come to your location to take a look at your vehicle.
Read Full Q/A … : Crank, No Start, replaced fuel and relay.
Why does my Tahoe start with the fuel pump relay pulled out or left in?
ANSWER : Hi there. Check to see what relay you have pulled. If indeed you removed the fuel pump relay and the engine still starts up, then check the oil pressure switch. An oil pressure switch will kept the engine running as it passes battery voltage to the fuel pump. When the engine builds up oil pressure, the oil pressure switch sends voltage to the fuel pump and bypasses the fuel pump relay. Unplug the oil pressure switch and see if the engine stops running. If you need further assistance troubleshooting your vehicle, then seek out a technician, such as one from Your Mechanic, who can assist you with why your vehicle is still running with the fuel system relay removed.
Read Full Q/A … : Crank, No Start, replaced fuel and relay.
It will not start on starting fluid, it dies right away. Replaced fuel pump, fuel compressive regulator, and fuel filter
ANSWER : Hey there. If the motor will only start with the use of starting fluid, this suggests you may have a fuel supply problem such as faulty or dirty fuel injectors. If you have replaced the fuel pump and fuel pressure regulator, we can reasonably assume that you are getting the correct amount of fuel pressure through the system. You will need to check the voltage at each of the injectors to be sure they have the proper amount of power. You may also need to check them to be sure they are freely spraying the proper stream of fuel. If you would like to have this taken care of, a certified pro from YourMechanic can come to your car’s location to diagnose the starting issue and follow through with a fuel injector replacement (or any other repair) as needed.
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Fuel pump engages. Batery good, alternator good volts, jump start helps when wont start. Temp does not matter. Intermittent?
ANSWER : Hello. Thank you for writing in. There are several reasons your vehicle may only start when jump starting. The first and most common is a build up of resistance that is causing you to need a boost of voltage to get the engine started. This may be due to poor battery cables, a bad ground connection, a poor starter solenoid, and a couple of other issues. The first thing you want to do is perform a visual inspection of the starting system. Make sure there is no corrosion build up in the battery cables. You can also check the resistance across these wires and make sure you have a solid connection between components. You then want to make sure the starter solenoid is doing its job. It is responsible for taking the small amount of electricity sent by the ignition and turning it into a huge electrical charge that is strong enough to push over the engine with the help of some gear ratios in its favor. Do some more testing, and stick to the basics before assuming its something seriously complicated.
Read Full Q/A … : Crank, No Start, replaced fuel and relay.
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.
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After replacing the fuel pump, filter, relay, and 2 of 4 injectors, my car still won’t start – 1997 Suzuki Sidekick
ANSWER : Hi and thanks for your question. This seems to be the camshaft sensor, crankshaft sensor, and the MAF (Mass Air Flow) sensor that is causing this issue. The MAF sensor will make the computer think that there is no air when there is air causing the computer to shut off the injectors or the ignition.
The camshaft sensor will tell the computer which cylinder is firing and where to apply fuel. The crankshaft sensor is where the computer knows where piston 1 is and when to fire the ignition and injectors, but it is not precise so the engine will not run correctly. If the crankshaft sensor is failing, it will cut off everything but allow the engine to crank only. Find the sensor that has failed and replace it.
If you need further assistance with your vehicle, then seek out a technician, such as one from YourMechanic, who can find and replace either the crankshaft, camshaft, or the MAF sensor.
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My car stutter starts, but only after driving it for a few minutes.
ANSWER : Hey there. This may also be caused by what is called the fuel pressure regulator. This is a unit that helps to maintain the fuel pressure at the proper level. When this is not working properly, the fuel pump may be pumping properly, but the fuel may not arrive at the fuel injectors at the proper psi. When this happens, this can cause a lean fuel condition which may cause the car to hesitate, misfire, or stall. If you would like to have an expert pinpoint the issue, a certified professional from YourMechanic can come to your car’s location to inspect the hard start problem and confirm which repairs are needed.
Read Full Q/A … : Crank, No Start, replaced fuel and relay.
