ka24de s13 fuel pump not getting power

[tchazlee]

I bought the car not to long ago and I have been messing with it a little. It turns over but wont crank so I checked the fuel pump and it is not getting power. I ran a jumper wire from the battery and the pump turned on. I checked the fuse and relay and they are both good and also getting power to both. I cant find any breaks in the wires anywhere so is there something I am missing?

[kyral]

Are you good with a multimeter?
the fuel pump doesnt just buzz and run the whole time the cars on. is it priming when you turn the key?. have you confirmed youre not getting any fuel to the cylinders? (check for spark too while you have the plug out)
theres a B/P wire of the ecu that if it were to break would cause the fuel pump to turn off
when you say you chedk the Fuel pump relay and it had 12v. did you check with the ign on? and confirm the relay socket has a 12v constant and a 12v hot on ignition pin? it should have 2 12v supplies while the keys on ign

[oLemurs]

Are you good with a multimeter?
the fuel pump doesnt just buzz and run the whole time the cars on. is it priming when you turn the key?. have you confirmed youre not getting any fuel to the cylinders? (check for spark too while you have the plug out)
theres a B/P wire of the ecu that if it were to break would cause the fuel pump to turn off
when you say you chedk the Fuel pump relay and it had 12v. did you check with the ign on? and confirm the relay socket has a 12v constant and a 12v hot on ignition pin? it should have 2 12v supplies while the keys on ign

i had the exact problem and still could never figure out why my pump wont turn on. i ended up wiring in a relay in the trunk and using a jumper wire up front. esentially the jumper wire acts as the signal so when you put the key in the on position it activates the relay. the jumper wire doesnt experience high voltage when you put the other relay on.

[tchazlee]

No when I turn the key on the fuel pump does not prime. I ran a jumper wire to the pump and the pump turns on and I can start the car. I found 2 broken wires at the pump today and fixed them but still nothing. I guess I need to locate that B/P wire to the ecu that you are talking about and see if I can find any problems with it. Would you happen to have a diagram of that wire?

[staying_chuki]

pin 87 gets 12v pin 86 gets ground pin 85 gets switched ignition pin 30 goes to wht/purple at plug in rear by fuelpump

^copy pasta not my info
Ive had fuel pump issues before, somewhat similar to your issue except i had no power all the time. Once i had confirmed that the fuel pump was working i just rewired it, probably would have taken me a lot longer to trace whatever the problem was. I didnt follow this exactly but its some info to go by.

If you would rather find the problem id say check the plug-ins, whatever tf they are called, im pretty sure the ecu sends a signal to the relay so maybe your problem is there.

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[tchazlee]

How would I be able to see if the ignition is sending power when turned on?

[staying_chuki]

How would I be able to see if the ignition is sending power when turned on?


Pull the cover off the key tumbler thing and find out what color the fuel pump wire is. Not 100% sure on the color, most of my wiring is ghetto so oem might be different. But yeh just check to see if theres power there at the ignition, and also check the ignition wire going to the fuel pump in your trunk. If you have power at the key wire but not at the pump wire it would be somewhere in between thats causing the issue.


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[brndck]

just FYI "turning over" and "cranking" are the same thing.

FIRING is different.

Nissan ecus like to burn out, and when that happens, the ECCS relay will not be commanded to switch.

you need to check for power (multimeter or power probe are the best tools for this) at the fuel pump while the key is switched from off to on

you need to check for fuel injector pulse (noid lights are the best tool) while cranking

you need to check for spark while cranking. spark plugs or a spark tester are the best tool for this.

if you have injector pulse, spark, and power to the fuel pump, and still no start, then you need to check fuel pressure, using a fuel pressure test gauge kit

go forth and report back.

[FaLKoN240]

I would suggest just getting a new ECU...