How to Check Your Fuel Pump
Check the fuel pump fuse., Check the voltage at the pump itself., Perform a drop test using a voltmeter.
Step-by-Step Guide
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Step 1: Check the fuel pump fuse.
Often, it's not the pump itself that fails to function, but the power that supplies it.
Check in your owner's manual for the location of the fuse box, then find the fuse that corresponds to the fuel pump.
Pull it out and inspect it for signs of failure.
If the fuse is blown, it will be broken or burned.
If it looks good, check the rest of the fuses related to the fuel system for signs of being blown and replace them, if necessary.
If no fuses are blown, have a helper turn the key while you listen for fuel pump relay clicking on.
If you need to replace a fuse, make sure you use one with a proper amp rating, never installing one with more amps than necessary.
If you find a blown fuse, that might be a sign that you've got a high amp draw and you need to check the individual circuits.
Try to replace the blown fuel fuse and try and start vehicle.
If the fuse blows again, a direct short is present and will need to be diagnosed.
Take your car into the shop to get it checked out. -
Step 2: Check the voltage at the pump itself.
Just because you're getting juice from the circuit doesn't mean that it's getting to the pump itself, which makes it important to check the voltage there as well.
Check out your vehicle's service manual to find out where to check and the proper procedure for checking it.
Test for source voltage, to determine whether or not the good charge that's leaving the fuse is getting to the pump.
If no power is making it to the fuel pump, then check the fuel pump relay circuit.
You could have a bad relay. , Check to make sure that the power wire shows the full voltage and the grounding wire shows that it's grounded properly.
If this electrical test reveals nothing, it's likely that your fuel pump is the problem and it will need to be replaced, though you can check more thoroughly by completing an additional pressure test.
If you show more than one volt difference, that means you've got a problem with corroded wires, or that you've got issues with the circuit on either the positive or negative side.
Take it into the shop for further testing and advice. -
Step 3: Perform a drop test using a voltmeter.
Detailed Guide
Often, it's not the pump itself that fails to function, but the power that supplies it.
Check in your owner's manual for the location of the fuse box, then find the fuse that corresponds to the fuel pump.
Pull it out and inspect it for signs of failure.
If the fuse is blown, it will be broken or burned.
If it looks good, check the rest of the fuses related to the fuel system for signs of being blown and replace them, if necessary.
If no fuses are blown, have a helper turn the key while you listen for fuel pump relay clicking on.
If you need to replace a fuse, make sure you use one with a proper amp rating, never installing one with more amps than necessary.
If you find a blown fuse, that might be a sign that you've got a high amp draw and you need to check the individual circuits.
Try to replace the blown fuel fuse and try and start vehicle.
If the fuse blows again, a direct short is present and will need to be diagnosed.
Take your car into the shop to get it checked out.
Just because you're getting juice from the circuit doesn't mean that it's getting to the pump itself, which makes it important to check the voltage there as well.
Check out your vehicle's service manual to find out where to check and the proper procedure for checking it.
Test for source voltage, to determine whether or not the good charge that's leaving the fuse is getting to the pump.
If no power is making it to the fuel pump, then check the fuel pump relay circuit.
You could have a bad relay. , Check to make sure that the power wire shows the full voltage and the grounding wire shows that it's grounded properly.
If this electrical test reveals nothing, it's likely that your fuel pump is the problem and it will need to be replaced, though you can check more thoroughly by completing an additional pressure test.
If you show more than one volt difference, that means you've got a problem with corroded wires, or that you've got issues with the circuit on either the positive or negative side.
Take it into the shop for further testing and advice.
About the Author
Michelle Lee
A passionate writer with expertise in DIY projects topics. Loves sharing practical knowledge.
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