Fuel pump

[america8371]

Hi everyone,My engine didn't get any fuel (disconnected hose to the fuel filter and it was bone dry) so I first checked the fuse (which was still good). Then I thought it was bad fuel pump, so I bought a cheap used fuel pump and bench tested it (worked perfectly). Still no fuel. Then I thought maybe it was the fuel pump relay, so I bypassed the relay, still no fuel. I honestly have no idea where to go from here. I heard somewhere that it could be the ecu (I have two and tried both, but no luck). My past experience with Nissans tells me to blame a bad ground, its always a bad ground, lol. Any advice would be greatly appreciated because I'm dying to finally see this thing on the road. Thanks in advance.

Also, I was wondering if hard wiring the fuel pump to the harness would fix the problem. I found a post on how its done. It sounds easy to do, but im actually i little confused as to where the cut wires are connected. If anyone could clear it up that would be awesome.

Here's the Post:

I re-wired my fuel pump today as i suspect it is crapping out or the relay has crapped out and hence is giving me really bad pressure, not bad but 5 to 10 psi less than it should. After i wired the new relay in it powered up for maybe 10 seconds, then kicked off and did not power back up? The fuel pressure that showed up on the pressure gauge of 43.5 psi was right bang on, i was getting 37 to 38 with key on before. Why would it dies just a few seconds after turning the key on? The pump no longer turns on at all?

I wired it like this.

1. white/purple wire.

Cut wire in half. Half that runs to the pump was wired up to +12v of the pump.

Half that runs to the harness was wired to the +12v white wire from the relay. This should switch it on right?

2. Blue/red (ground???)

Cut in half and grounded each wire out to the chasis.

Relay was wired with 12 gauge running right to the battery. The +12v switch got wired to the white/purple harness wire, blue positive to the white/purple running to the fuel pump.

I'm confused why it would power on properly then just stop all of the sudden??? The inline fuse was still good, i used a 20amp one.
Modified by america8371 at 7:15 AM 8/9/2007

[america8371]

I followed these directions and set everything up properly. I cut the white/purple wire in half and connected both halves to their proper places on the new relay that i put in the back. I grounded the relay and wired it to the battery.

Heres a picture of how I wired it

But the pump didnt start.

I decided that instead of connecting it to the white/purple wire that goes to the fuel pump positive terminal, I would connect it directly to the positive terminal of the fuel pump.

And when i turned the key to the on position, the pump started running.As happy as I am about finally getting it to run. I was wondering if I wired it correctly. I wouldn't want to cause damage over time.And if the way I wired it is ok, how would i route the wire that goes from the relay directly to the positive terminal of the fuel pump if the fuel tank plate is going to be blocking it.
Modified by america8371 at 4:18 PM 8/9/2007

[america8371]

bump

[america8371]

has no one here with a S13 rewired their fuel pump before?surely one of you folks can tell me if did the re-wire correctly.

[180fan]

I didn't post in the hope you would

1. search2. lurk moar

Surely one of us has rewired the fuel pump correctly before. If you had searched, you would have found this out long before waiting for

1. a reply2. waited more than 4 hours before bumping between your 2nd and 3rd posts.

Now with that said, it's a very simple process. You've already got the picture down, you just need to hit the one labeled "connector" off a wire that's triggered when your key is in the "on" position.

[america8371]

I didn't post in the hope you would

1. search2. lurk moar

Surely one of us has rewired the fuel pump correctly before. If you had searched, you would have found this out long before waiting for

1. a reply2. waited more than 4 hours before bumping between your 2nd and 3rd posts.

Believe me when i say that i did search (i actually find searching more useful than posting). I did find a thread about rewiring the fuel pump but i just needed to clarify some things (the thread didn't have a picture for me lol), thats why I decided to post. But your right, I should've waited much longer before bumping.

Now with that said, it's a very simple process. You've already got the picture down, you just need to hit the one labeled "connector" off a wire that's triggered when your key is in the "on" position.

Just to clarify, I have to connect pin 30 in the picture to a wire that is activated by the key in the on position, ok that makes perfect sense, but wouldn't that be the white/purple wire that its already connected to? I mean.... the fuel pump runs when the key is in the on postion. I was just worried about connecting pin 87 directly to the fuel pump positive terminal. Is that ok to do? Please, share some more of your 240 wisdom.

[180fan]

You might have to double check on the "on" or "acc." The more I think about it, the more I think it triggers and primes off the "ACC" position rather than the "on."

The hook up to the + on the fuel pump is right on.

[america8371]

Ok so the way I wired it sounds good. Thanks a lot 180fan, I really appreciate the help. My S13 is one step closer to being on the road.

[180fan]

awesome lets hear how it turns out. what else you got planned for the ride?