CUL8ER

Ok I asked this question on another thread. But I think you guy's that have done this swap with a after market ecu/ecm should know what to do.

Ok nothing changed in the fuel pump hanger/basket/bucket. But I did remove the stock ecu/ecm. And now my fuel pump will not turn on.

I just read that the stock fuel pump harness has the negative/ground ran to the ecm for a signal ground. So with the factory ecm gone now I don't have a ground signal.

I have gone through the wiring to the fuel pump hanger and I have 2 black wires on the fuel pump harness
1 with a yellow stripe(pin out #1). and 1 that's all black.(pin out #3)

So my question is, Is the all black wire the ground? I have found/read that the 1 wire with the yellow stripe is the 12+ignition source, so would that make the all black wire the ground?
Thanks in advance..


Edit: I went back to look at the factory wire loom and at the orig ecu clip. And of course, bam there it was from right to left on the factory ecu connector pin out #1 was black w/ yellow stripe and pin out #3 was black.
I was just on the phone with sidewayyracin and he said he had to do the same thing(ground pin out #3) when he ran the chase bay.

karlt

The fuel pump is not grounded through the ECU; it draws too much current for the ECU to handle. Instead, the pump is grounded to the chassis. The pump receives power through a fuse and relay on the IPDM E/R. The ECU controls the relay. For a complete description of the circuit, check out the ec.pdf section of the Service Manual.

jksstar

iTrader: (7)

Karlt is right. Its grounded to the chassis. I'd have to look at mine to see what color it was, but I just cut the power wire about 5" above the plug. Then used my new 12v wire to power the pump still using the stock plug.

I got the info on here on what wire to tap into.

jksstar

iTrader: (7)

Here you go

https://my350z.com/forum/maintenance...ring-help.html

mkiv20vt

Yup. The above info is great!

CUL8ER

Well at a loss here then. I cut and ran the all black wire to a ground, and I cut the black w/yellow stripe wire and ran it to the fuel pump fuse in engine bay w/ a add-a-fuse and still no fuel pump.

Both wires cut from right before ecu connector.

rcdash

iTrader: (18)

If the fuel pump is getting power (fuse not blown), then the fuel pump must be bad. Pretty easy to test with a multimeter?

CUL8ER

I guess I could run through the wires with a multimeter. But really would like to hear from someone who has done this before with a aftermarket ecu and with the factory fuel pump harness.

jksstar

iTrader: (7)

Try to hot wire the pump, just run a wire right off the battery to the + wire at the pump. Will know right away if your pump is bad.

what ECU are you running now?

CUL8ER

Looks like that's my only option right now. I have the AAM sugre tank and 044 bosch runninig off the stock 350z fuel pump harness and a 485 walbro in tank.

This set up was running a 255 before I just had Dynosty replece it for the 485.
I disconnected the 044 and ran it strait off the battery and it worked..
So now I will go through the stock fuel pump harness and just re-wire it strait, not off of the ecu.

I would hate to do this and find out that Dynosty didn't run/wire the 485 the right way.

My ecu is a Holley HP efi. doesn't seem to be to many members on here running that ecu, more on ls1tech.

CUL8ER

I have the Holley efi system set up as a stand alone. I need the walbro 485 and the bosch 044 to run all the time. With a 12+ ignition/keyed source. I will have a Magnafuel 4303 running through 1 of the inputs on the holley and have it turn on @ 10psi of boost or so, depending on fuel loss.

The car was wired like this for 5 years with the 255 and the 044. So other then just replacing the 255 for a 485 and not running the stock ecu I have run into this problem.

I will just hot wire both pumps(485-044) with separate releys. I made/wired up a Dorman 4 post 30amp relay last night at work. I will get to it this weekend.

jksstar

iTrader: (7)

The more I read your post I'm gonna say its wired up wrong.

Did they wire it up to the 350Z fuse /relay block or install new fuse block ?

When you hot wired the pump did you try and start the car?

Also I sent you a PM before i say this post

CUL8ER

Thanks again Justin,

I have been doing research for 4-5 days now. The fuel pump set up before was made to run with the stock ecu. So I will just take that generic relay wiring diagram and set it up like that in post #4.. After talking with a Holley tech yesterday. I will use the holley's ecu fuel pump wire(green wire) as a 12+ ignition source. That will power on both pumps.

I have gone through all the wiring, relays,fuses with the exception of not just hot wiring it. I have tried everything.
When I disconnected the 044 and ran a neg/pos strait from battery it worked so it's not getting power from the battery It was running good before I took the stock ecu out so that should be my problem.

Thanks, I just didn't have a grasp on how the stock ecu played a role, So I will just hot wire the 485. And put the 044 on it's own relay. instead of piggy-backing off the 485's relay.

The black w/yellow stripe wire from fuel pump will go to #87 on a Dorman relay. #30 on Dorman relay goes to pos side of battery. #85 on Dorman relay goes to a chassis ground.
#86 on Dorman relay goes to the Holley's fuel pump trigger(12+v) wire.(green wire)

The holley's green wire is a 12+ ignition source and when the holley ecu get power/turned on that will trigger the green wire to activate the 485 and the 044. So I should be good to go.

CUL8ER

A buddy came over and we hard wired it to turn on the pumps 485 and 044.
So both pumps turned on from the hard wiring and pushing fuel.
Thanks guy's you helped me, But I did do all the work.

karlt

CUL8ER,

I think I've found the cause of your problem. Your Holley kit is providing +12V to the fuel pump relay coil and assumes the other side of the relay coil is connected to ground. In the stock setup the fuel pump relay coil receives +12V directly from the battery through the ignition key, and the ECU provides the ground (see attached sheet from the Service Manual). So in your situation, the relay coil sees +12V on both sides and the relay stays open.

CUL8ER

Thanks karlt, That image is very helpful.

When my buddy stopped by, he had that same pdf. file on his phone. He remembered when he did his first ls1 350z swap that the chasebay kit came with a metri-pack connection and 1 wire to ground off 1 of the wires on the ecu connector. So we just did that and both pumps turn on when key is on acc.

So it was as simple as to just grounding 1 of the wires going into the stock ecu connector. Since I had it all hooked up and running for X amount of years I know it was something simple.

karlt

Glad it worked out.

jksstar

iTrader: (7)

Glad you got it worked out!! can 't wait to see the end product!