Help with fuel pump

[tre4s13]

What wires do I use to bench test my pump? I don't want to be back there shorting wires over gas and landing on top of the house. Oh yeah, I have a STOCK s13.

[Mr.s13r]

if you want to test your pump just pull off the fuel line from the fuel filter that goes into fuel rail on the intake and has someone else crank the car to see if fuel come out. GL, hope all the fuel splash every where on your engine. It a sign that your pump is working =)

[rb25_s13*CHUKI]

bend over touch your toes,clap twice,do two jumping jacks and kiss your dog. then you should be good

[tre4s13]

bend over touch your toes,clap twice,do two jumping jacks and kiss your dog. then you should be good

That shit didn't work, and now...I HATE YOU!

[Hywarp161]

but now his dog likes him

[tre4s13]

Ok let me clarify:

Fuel pump isn't priming.

Wire side of relay has NO power.

10a fuse and green relay replaced.

75a fuse is fine.

[GSXRJJordan]

Corrected below by Russ.

The FSM says there should be somewhere around 2-4ohms resistance between the + and - leads of the fuel pump, so if you have a multimeter, that'll tell ya if the pump's healthy.

[tre4s13]

thats the thing, out of the 5-6 wires...idk which is + OR - thanks for the advice tho. I do have a dmm, just don't know what to probe.

[96Turbo]

thats the thing, out of the 5-6 wires...idk which is + OR - thanks for the advice tho. I do have a dmm, just don't know what to probe.

how bout you just pull the pump out of the tank....only takes 5 min or so

then you won't hafta worry about blowing yourself up either :bigok:

[japslapsilvia]

black/pink is pump turn on.

[projectRDM]

The relay is a switched ground. The fuel pump (and its relay) receive constant 12v power, the ECU sends a ground to the relay, which sends a ground to the pump to turn it on.

The FSM says there should be somewhere around 2-4ohms resistance between the + and - leads of the fuel pump, so if you have a multimeter, that'll tell ya if the pump's healthy.

Nope. The ECU trigger is a ground, but the relay then switches power to the fuel pump. The black/yellow wire is the +12V signal from the relay to the pump. Black/pink is signal to the relay from the ECU.

[GSXRJJordan]

Nope. The ECU trigger is a ground, but the relay then switches power to the fuel pump. The black/yellow wire is the +12V signal from the relay to the pump. Black/pink is signal to the relay from the ECU.

zomg. I should have looked at my relay before posting... yes, the black/yellow wire is +12v, and I believe the ground for the pump is a thick black wire with the pink "spots" every inch or so (standard Nissan ground coloring). There's also a couple smaller wires for fuel level.

Pull the 4 bolts to the cover, look at the wires as they go into the fuel pump connector, and then check impedance between the + and gnd wires. 0 ohms/short means bad pump, and no conductivity (infinite ohms) means bad pump/wiring.

[tre4s13]

idk which wire is + or - but there's a black and yellow, the rest has stripes. I tested the black and yellow and they ohmed @ 9, which I assume is a good thing?

[Kalashnikov]

Corrected below by Russ.

The FSM says there should be somewhere around 2-4ohms resistance between the + and - leads of the fuel pump, so if you have a multimeter, that'll tell ya if the pump's healthy.


Screw the FSM!

Who has a voltmeter anyway.

Yes, just take off the fuel filter, get a pan, crank it, and if fuel squirts into your eye, the pump works.

Then get a Z32 Fuel filter and replace replace.

[Kalashnikov]

In addition, to do an even better test.

just unscrew the fuel Rail, pop the rail up.....

Place a piece of white xerox paper under the injectors, Crank the car..

you will see fuel squirt out,

and which ever injector doesn't squirt, bamm. you solve the problem.

You can see the fuel dots that is squirted on the paper.

If one to 3 are not squirting, you have bad injectors, if all 4 not squirting, then most likely bad pump.

And that is the Tech of the day~ How to check the Fuel system and diagnose the source....Bet no one thought about that huh!

KA injectors go out commonly. I replaced a lot of them in my cars.

[tre4s13]

Um...AK i wasnt getting ANY FUCKING POWER! So that wouldnt have worked, now that i tested the pump, and it primes, i will be rewiring its own fuse, relay, and switch.

Like this for example:
Wiring a Relay for Accessories (http://www.r1200gs.info/howto/relay.html)

Good idea? Someone with electrical experience help me out.

[GSXRJJordan]

In addition, to do an even better test.

just unscrew the fuel Rail, pop the rail up.....

Place a piece of white xerox paper under the injectors, Crank the car..

you will see fuel squirt out,

and which ever injector doesn't squirt, bamm. you solve the problem.

You can see the fuel dots that is squirted on the paper.

If one to 3 are not squirting, you have bad injectors, if all 4 not squirting, then most likely bad pump.

And that is the Tech of the day~ How to check the Fuel system and diagnose the source....Bet no one thought about that huh!

KA injectors go out commonly. I replaced a lot of them in my cars.

This is generally a bad idea, because those O-rings are tricky, and love to leak. Who does diagnostic work without a voltmeter?

OP - I guess you fixed the problem? To wire in a standard "Bosch-type" relay instead of the relay from the car, hook it up like this:
85/86 - one lead to +12v power, the other to the black/pink striped wire off the ECU harness.
87/30 - one lead to fused +12v power, the other to the black/yellow wire coming off the fuel pump.

Then make sure the pump is grounded well, and that's it! Do you know for sure the stock relay/relay wiring was the problem?

[g6civcx]

I don't know what is going on any more plus I don't feel like looking at wiring right now.

Just do what Russ said. If that doesn't work, replace the car.

[projectRDM]

This is generally a bad idea, because those O-rings are tricky, and love to leak. Who does diagnostic work without a voltmeter?



If you pull the whole rail you're fine. Pulling each injector is pointless though. And while a VOM is great there's a shit ton of people who have no clue how they work. It's like suggesting a noid light to test signal to the injector, you'll get a slew of 'huh?' from most people.

[s13Carlo]

have you checked your relay, if you havent do that and if its bad replace it then check the fuel pump by undoing the deliver fuel line off the filter and seeing if it pumps.

[tre4s13]

It's very apparent that some of you guys can't read a question fully.

A. WIRING for fuel pump relay is DEAD

B. WIRING IS DEAD DAMNIT!

C. I made my own circuitry with Wiring a Relay for Accessories (http://www.r1200gs.info/howto/relay.html)

D. Thanks for the help, the few of you who knew what I was asking.

That is all.