fuel pump help - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

rollinrps13 · 03-26-2010, 03:15 PM

im getting power to the pump but it doesnt cut on..its a new pump i got beacause i thought the old pump just went out..if anyone knows any possile reason why the pump wont cut on when its getting power through the harness please let me know..please help im stumped lol

army240 · 03-26-2010, 03:19 PM

check your ground... and i'm assuming when you say "It doesn't cut on" means it's just not working, like not pumping, right?

The other reason, you've got voltage, but no amperage, I've seen that sometimes, though it's very rare!

Frank

rollinrps13 · 03-26-2010, 03:23 PM

i checked the grounds they all look tight. the inside is striped down so ill go double check..what would cause the low amp issue?

army240 · 03-26-2010, 03:29 PM

hummm... I really don't know. I've seen that once in my life... didn't have time to diagnose that, so I just put a new wire from the ignition to the relay. Cause it was against all electric laws I know... They only thing I could think of, it could have been a resistance BEFORE the relay, and I did checked the voltage with the relay disconnected. When I put the relay in... the circuit was complete, the resistance was taking all the voltage, so no more voltage for my relay. Anyway...

As I said, there is more chance this is a grounding problem.

Frank

xpertsnowcarver · 03-26-2010, 03:52 PM

Check your fuse, check the harness connections (make sure the terminals didn't slip out.)

This is what you need to do when the above is fine.
Get a test lamp to check for continuity.
Ground the test lamp to the chassis.
Wedge the needle into the Ground terminal of the fuel pump. (Read your FSM or figure out what it is.)
The light and/or pump should turn on.

~~~

If it does, check your ground, which runs to your ECU. Read your FSM.

If it doesn't, wedge the needle into the positive terminal.

~~~

If the the light turns on, there is something wrong with your fuel pump.

If it doesn't turn on, then your fuel pump isn't getting power.

army240 · 03-26-2010, 04:08 PM

Quote:

Originally Posted by xpertsnowcarver

If it does, check your ground, which runs to your ECU. Read your FSM.

If it doesn't, wedge the needle into the positive terminal.

~~~

If the the light turns on, there is something wrong with your fuel pump.

If it doesn't turn on, then your fuel pump isn't getting power.

Relay is grounded by the ECU, but the fuel pump itself is grounded to the body IIRC.

xpertsnowcarver · 03-26-2010, 04:36 PM

Right, you are correct. This is before the fuel pump, part of the positive side of the circuit. It is rather confusing which is why I recommend one refers to the FSM.

03-26-2010, 03:15 PM	#1
rollinrps13 Leaky Injector Join Date: Sep 2009 Location: nashville Posts: 102 Trader Rating: (2) Feedback Score: 2 reviews	fuel pump help im getting power to the pump but it doesnt cut on..its a new pump i got beacause i thought the old pump just went out..if anyone knows any possile reason why the pump wont cut on when its getting power through the harness please let me know..please help im stumped lol

03-26-2010, 03:29 PM	#4
army240 Zilvia Junkie Join Date: May 2008 Location: Quebec Age: 36 Posts: 306 Trader Rating: (1) Feedback Score: 1 reviews	hummm... I really don't know. I've seen that once in my life... didn't have time to diagnose that, so I just put a new wire from the ignition to the relay. Cause it was against all electric laws I know... They only thing I could think of, it could have been a resistance BEFORE the relay, and I did checked the voltage with the relay disconnected. When I put the relay in... the circuit was complete, the resistance was taking all the voltage, so no more voltage for my relay. Anyway... As I said, there is more chance this is a grounding problem. Frank Last edited by army240; 03-26-2010 at 03:40 PM.. Reason: more info

03-26-2010, 03:52 PM	#5
xpertsnowcarver Post Whore! Join Date: Jan 2007 Location: LA, CA Posts: 2,667 Trader Rating: (44) Feedback Score: 44 reviews	Check your fuse, check the harness connections (make sure the terminals didn't slip out.) This is what you need to do when the above is fine. Get a test lamp to check for continuity. Ground the test lamp to the chassis. Wedge the needle into the Ground terminal of the fuel pump. (Read your FSM or figure out what it is.) The light and/or pump should turn on. ~~~ If it does, check your ground, which runs to your ECU. Read your FSM. If it doesn't, wedge the needle into the positive terminal. ~~~ If the the light turns on, there is something wrong with your fuel pump. If it doesn't turn on, then your fuel pump isn't getting power. __________________ My YouTube Channel

03-26-2010, 04:36 PM	#7
xpertsnowcarver Post Whore! Join Date: Jan 2007 Location: LA, CA Posts: 2,667 Trader Rating: (44) Feedback Score: 44 reviews	Right, you are correct. This is before the fuel pump, part of the positive side of the circuit. It is rather confusing which is why I recommend one refers to the FSM. __________________ My YouTube Channel

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03-26-2010, 03:19 PM	#2
army240 Zilvia Junkie Join Date: May 2008 Location: Quebec Age: 36 Posts: 306 Trader Rating: (1) Feedback Score: 1 reviews	check your ground... and i'm assuming when you say "It doesn't cut on" means it's just not working, like not pumping, right? The other reason, you've got voltage, but no amperage, I've seen that sometimes, though it's very rare! Frank

03-26-2010, 03:23 PM	#3
rollinrps13 Leaky Injector Join Date: Sep 2009 Location: nashville Posts: 102 Trader Rating: (2) Feedback Score: 2 reviews	i checked the grounds they all look tight. the inside is striped down so ill go double check..what would cause the low amp issue?