Fuel Pump issues

[Miami240z]

I just finished getting my SR in a few days ago and wired and installed my walboro pump. The pump should come on when I turn the key to ignition but it doesnt. I checked the wires in the trunk for power but there isnt any. When I check the pump relay wire on the harness its fine. I did the harness myself no prob. The dash power is fine and the engine cranked great. All my fuses are good but no power still gets to the pump. My last guess would be that from me cranking the engine over so many times before I did the pump, could I have drained enough power from the battery that it wouldnt be strong enough to reach the trunk? This is the last thing I need to fix to get the engine running and im getting very frustrated. Thanks in advance.

[jdm_s14_zenki]

i had to wire mine directly to ign. relay or accessory, i forget which one.

[cotbu]

jump the relay 1-3 on the socket, fuel pump will not stop after 3sec, will turn off when key turns off. ECU will not cut fuel at decel or when boosting.

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[Miami240z]

Excuse me if i sound like a retard but what do you mean by jump 1-3 on the socket? and how did you wire it directly to ignition?

[jdm_s14_zenki]

extend the fuel pump power wire to the relay fuse box under your steering wheel area..theres an ignition fuse there.

Or jump the relays like the other guy said. ive never had to do that before.

[Miami240z]

Im gonna try that now.

[jdm_s14_zenki]

did it work?

[Miami240z]

Ofcourse I dont have enough wire to run it to my fuse box under the steering wheel but would it be the same if I ran power from my cig lighter and just grounded the pump to my chasis?

[cotbu]

Get a 2-3 inch piece of 14 or 16 gauge wire 2 male spade connectors.

[jdm_s14_zenki]

so u have to press in your cig lighter when you want your FP to work?
dont sound right to me. you need a wire that will activate when you turn the key.

[tchenku]

this happened to a buddy of mine. i can't remember what i did to fix the problem. i'll call him up and ask him and i'll get back to ya!

[Miami240z]

I was thinking more along the lines splicing it to the wires in the center console that go to the cig lighter that way it will turn on and off with the turn of the key.

[cotbu]

Jump the relay turn the key, car starts
Oh yeah if you bypass the relay completely by rerouting the wires, instead of jumpimg... IACV needs that relay too! IIRC.

[jdm_s14_zenki]

what he said

[Miami240z]

I dont exactly know what you mean by jumping the relay.

[g6civcx]

Why are people telling him to jump the relay? If the relay is broken, fix it. If there is broken wiring, fix it. If the fuel pump is bad, replace it.

What benefits are there to having a pump that is permanently on with ignition power? The ECU needs to cut the fuel pump for a reason.

Quite frankly I'm really sick of seeing this topic pop up once a week. Maybe I'll just write a comprehensive fuel pump diagnostic thread and be done with it. Maybe

[t0ttzg0tskillz]

Yes, you should man..I still haven't gotten home to work on it. I don't know what i'll possibly be home either. Anyways, that would be awsome to do that. and HIGHLY APPRECIATED!

[jdm_s14_zenki]

Originally Posted by g6civcx

Why are people telling him to jump the relay? If the relay is broken, fix it. If there is broken wiring, fix it. If the fuel pump is bad, replace it.

What benefits are there to having a pump that is permanently on with ignition power? The ECU needs to cut the fuel pump for a reason.

Quite frankly I'm really sick of seeing this topic pop up once a week. Maybe I'll just write a comprehensive fuel pump diagnostic thread and be done with it. Maybe

what he said. but ya, ive NEVER had a problem with my fuel pump wired to ignition. when i turn the key on, my fuel pump turns on. when i start the car, my fuel pumps on. when i step on the gas, the fuel pumps on. when i turn off the car, my fuel pumps OFF. cant be too complicated...why in the hell would the ecu need to shut off fuel? so you can go lean and detonate?

[cotbu]

why in the hell would the ecu need to shut off fuel? so you can go lean and detonate?

Pretty much yeah!, Ecu does not completely turn of the pump but cuts the voltage IIRC which will cause a lean condition.... BAD

This mod is mostly done after you have 12v or close as possible, to the fuel pump on turbo cars. Why? Leaning out under boost is a bad thing.

[g6civcx]

Originally Posted by jdm_s14_zenki

why in the hell would the ecu need to shut off fuel? so you can go lean and detonate?

I hear you on this, but you also have to balance this with the fact that any time you recommend a modification, you have to understand how the system as a whole will be affected. You have to look at how the wiring is done. It has to be clean, and provisions has to be made for safety.

The fuel pump circuitry sits on its own line. You need to clarify that if you piggyback it onto the existing ignition wiring, you have to look at the maximum load the system currently expects to support. Then you add in the maximum load the fuel pump is expected to draw. If the sum of the two max loads exceeds the max capacity of the ignition circuit, you're going to have problems.

So until you have addressed those questions, it's not good to say just piggyback the fuel pump onto the ignition system.

The best way to do that would be to use a relay and tap into the ignition system as a power source. Only a small current will be drawn to activate the relay, which draws a large current from a different circuit. This is how the stock system works.

And actually all you would need to do is take the wire that goes from the fuel pump relay to the ECU and slice it in half. Remove/tuck away the side that goes to the ECU. Ground the side that goes to the relay. Now the relay thinks that the ECU is always turning the pump on. Much easier and safer than trying to piggyback onto another circuit.

[Miami240z]

Well ive traced the wire that goes to the + line on the pump which has no power. Its black with yellow stripe and goes along the drivers side flooring to a white bow with a bunch of other wires. Still no power up to the box. Where would I look to trace the power source to the box?

[g6civcx]

Is this an S13?

[jdm_s14_zenki]

g6 is smart.

[Miami240z]

93 S13 coupe

[Miami240z]

Jumped the relay. As far as im concerned, problem solved