# Testing Fuel Pump



## phill (Oct 22, 2006)

The car is a 94 Altima GXE...about 165,000 miles

I'm pretty sure that the fuel pump is not working, but for $200+ (replacement cost) I want to be sure.

I have tried to listen for the pump to come on but I cant hear it. I even pulled the back seat out so I could try to hear it...still cant, Like I said...I'm pretty sure its gone.

My question is....is the something that I'm missing that would cause the pump to not come on? Is there a way to test the fuel pump? I cant think of anything....but I'm no expert.


Any help would be great!

Thanks


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## phill (Oct 22, 2006)

Well I did a little more looking around...heres what I found.

You will need to remove the rear seat to get to the pump.


*Electrical Test *

Remove the fuel pump inspection cover to access the fuel pump electrical harness. 

Turn the ignition switch OFF. 

Disconnect the fuel pump electrical connector. 

Measure the resistance between the fuel pump terminals. Resistance should be 0.2-3.0 ohms @ 55°F (23°C). 

If resistance is not within specification, the fuel pump may be faulty. 

If the fuel pump resistance is within specification, check fuel pressure. 



*Pressure Test *


Properly relieve the fuel system pressure. 

Connect a fuel pressure gauge between the fuel filter outlet and fuel feed hose. 

Start the engine and read the fuel pressure. 

Fuel pressure should be approximately 21 psi (272 kPa) a few seconds after the ignition switch is turned from OFF to ON. 

Fuel pressure should be approximately 12 psi (213 kPa) with the engine idling. 

Stop the engine and disconnect the fuel pressure regulator vacuum hose. 

Plug the vacuum hose at the intake manifold and connect a hand operated vacuum pump to the pressure regulator. 

Start the engine and note the fuel pressure as vacuum is applied and released. 

Fuel pressure should decrease as vacuum increases. 

If fuel pressure does not respond as specified, the fuel pressure regulator may be faulty. 

If fuel pressure responds as specified, but fuel pressure is not within specification, the fuel pump may be faulty.


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## mr2mike (Oct 9, 2005)

Great insight, this will help a lot! 
Where did you get the specs for the pump?
If you had an online service manual I'd love an email copy.


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## phill (Oct 22, 2006)

I found that info online some where.....I cant remember now....I posted all the info on the fuel pump that they had.

Turns out that my pump was working some of the time.....a new one fixed the problem:fluffy:


Its easy to get to also......not more than 10-15 minutes of work.


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