Thanks Santa (the neverending trials of the 400,000klm, 400kw, RB30, manual swapped Stagea)

[niZmO_Man]

ok... so I read "B-52" can someone photoshop 4x turbofan engines onto a Stagea please?

[Duncan]

So, as it turns out, a new wire was the answer I went for, but getting there was not straightforward...

Firstly, I'd been told before by shops that had worked on the car that it had some weird factory wiring, and I can now confirm that is true in at least a couple of places.

For example....that very purple/white wire that provides IGN power to ECU pin 31.....I traced it out of the ECU loom into a connector high on the nav's A pillar under the dash, where it headed up and out of site across the dash, then back down at driver's A pillar. After trying about 8 different relays I found it coming into the back of the fuse box, and confirmed it was the same wire with a multimeter* (more to follow on that....

So, which fuse is the ECU IGN power connected to in my car? 

Very top right, labelled IGN (good), 10A (good), Auto Trans Control (WTF?). It's not impossible it has been f**ked with before, but if so someone removed the pins from the back of the fuse box and moved it somewhere else, noting an AT control fuse would be functionally useless as the car was auto converted to manual long ago. It is not simply a wire cut and joined to the wrong place, both ends of the wire are the same colour just one is in the wrong location (you can see there is an IGN Engine Control fuse in the bottom row 4th from the right.

Note, that is the fuse box sticker from my actual car, so either I have the wrong coin holder sticker, someone f**ked with it post factory, or factory sticker does not match the wiring.....whichever option it is just plain weird.

Undermining the likelihood of someone having gone to that trouble to move a power feed when everything else in the loom had already been butchered....the fuse next to it IGN 7.5a ABS doesn't even have a wire running to it....so no idea where that fuse is on this car.

All strange. But not the problem with my ECU power.

[Duncan]

Now I'd said earlier I'd checked the fuses, and per @Stick180's suggestion I checked them all again. The check was to use the multimeter in continuity mode on the top of each fuse where the little metal tabs are available for that purpose.

All good....except that very "A/T Control" fuse was actually blown when I pulled it out and looked at it. Put it back in, tested it again, there is continuity to both sides even though the fuse is blown. I'll need someone smarter than me, but my suspicion is that I was getting a circuit through a power supply, through an incandescent globe somewhere, to earth, to the shorted wire and back to the other side of the fuse, making it look like the fuse was OK when it wasn't....please anyone that understands this f**kery explain it to me.

Bottom line....that suspicious purple/white wire, in an undamaged factory loom, that goes to the the wrong place in the fuse box has a dead short to earth, confirmed from both ends.  How a single wire in a factory loom can be shorted, especially the best protected loom in the whole car (underneath the top of the dash) is going to keep me awake at night because surely whatever caused the damage has (or will) damaged other wires in that loom too.

So, to finish this long and sad story....cut the purple/white wire where it exits the fuse box, ran a new wire from there to the ECU loom pin 31, fired it up and drove happily into the sunset. Only 4 days of head scratching and peering into footwells to get me there.

Another collection of wire removed (in addition to the earlier photo) and a bunch of 10a fuses that gave their lives for the trouble shooting....thank you for their service. 

And, since the car was in the shed I resealed the cam cover (first time I've ever had a new seal leak on an RB, but the Stagea is that kind of lucky), and I put in the boost doc cam splash plates to try and turn down the blow by a bit while I was there.

Which, was all good because it also let me find the slow coolant leak, turns out it was from the turbo water supply which I nipped up again (the banjo bolt got new washers, and I tightened the hose end and hose to banjo fitting while I was there)

[Stick180]

Well, what a journey that was..

[Dose Pipe Sutututu]

Might as well wrap the dump 

[GTSBoy]

11 minutes ago, Dose Pipe Sutututu said:

Might as well wrap the dump 

You don't think he should leave it to torch the heat hoses?

[Duncan]

nah the heater hoses are fine, I just use the dump pipe as a booster until the coolant warms up

[MBS206]

@Duncan a meter will read continuity, so long as resistance is below a certain threshold.

 

For example, on a headlight globe, you'll probably manage to get your MM to beep for continuity.

 

I always go with measuring resistance.

 

I've had some digital Multimeters beep continuity even with a 100ohm load.

 

Now as for that wire that should be undamaged earthing out... I really really don't want to say it, as I hope it's not the case... Do you happen to have any evidence of mice/rats around?

[soviet_merlin]

On 07/06/2024 at 5:23 PM, Duncan said:

So, 2 months later, I just couldn't see any way to be happy with that tank setup. Basically the baffle area is too big and too leaky, the sender was miles off and the no low fuel light thing really bugs me. Other than the fact the fuel hat could safely supply enough power to the pump, it was worse than factory. Biggest thing that bugged me is it would still run out of fuel in medium-high g corners from about 1/4 tank down which is annoying when you are trying to have a zoom, not to mention potentially engine killing if it gets just the right amount of lean-ness....and we've got a few of those corners in our round trip to town (well, bunnings...)

So, credit to Frenchy's, they have put together a much better designed setup with what is effectively an in tank surge setup.

...

So....I'll report back how it handles low fuel, and if the sender has any relation to actual fuel level in the tank....

So, how do you feel about the Frenchys surge tank setup @Duncan? Have you had a chance to try it out more?

The sketchy wiring in my fuel pump setup has decided to melt and die and I'm looking for a solid replacement now.

My fuel hat is toast so the Frenchys kits providing it all look promising.

[Duncan]

Yeah the latest style kit has been trouble free, I've done a fair few klm on it including pushing a bit on low fuel and it hasn't been surging (that's not an endorsement for race use, I haven't tried that low, or that hard cornering!).

For street use it has been a good thing, handles the high current OK, only real issue is it is not cheap

[soviet_merlin]

Thanks Duncan! Yeah it's street use for me only. Maybe occasional track day.

Any difference in noise when running with the two pumps? I would expect the lift pump to be more quiet than the main pump so hopefully not?

And yes, unfortunately quite a big price difference to the simple hanger setup. Though I'm usually willing to trade money for better reliability and future-proofing. Buy once, cry once and all that. I'd be very happy to never have to deal with fuel pump / wiring issues again  

[Duncan]

No, it is still quiet enough with the interior in place, no worse than factory (I think, its been a while....)

Modern pumps are pretty quiet compared to the old school 040 etc which run loader than the motor

[Duncan]

BTW, don't forget to make sure your fuel tank is full before attempting any work on the fuel system. Ideally in the middle of winter when the fuel is about 5o as well.

[MBS206]

27 minutes ago, Duncan said:

BTW, don't forget to make sure your fuel tank is full before attempting any work on the fuel system. Ideally in the middle of winter when the fuel is about 5o as well.

Do you want to come do the fuel pump in my Skyline Duncan? It'll be a pleasure for you, as the middle of winter is still about 19c in the middle of the day, and the fuel tank is bone dry... 😛

[Duncan]

nah, sounds too easy

[soviet_merlin]

1 hour ago, Duncan said:

No, it is still quiet enough with the interior in place, no worse than factory (I think, its been a while....)

Modern pumps are pretty quiet compared to the old school 040 etc which run loader than the motor

Neat, thanks! There's a Walbro 460 in there currently and it has never bothered me. If it's not getting any worse I'm fine with that.

1 hour ago, Duncan said:

BTW, don't forget to make sure your fuel tank is full before attempting any work on the fuel system. Ideally in the middle of winter when the fuel is about 5o as well.

Murphy's law is inviolate. So don't you worry, I've got you covered. I filled up the tank just that morning on the way home. It's about as full as can be.

I'm not going to touch it though. The car will go to Unigroup to get it done properly. See how it goes.

[soviet_merlin]

On 01/04/2024 at 7:52 PM, Duncan said:

Annoyingly the Frenchy's Performance Garage fuel hat and baffles (version 2, not current) deletes the low fuel warning light, and although it comes with a new sender

One more question if you don't mind. Is the first kit you tried the same one as they currently sell as their fuel-pump-hanger kit?

https://frenchysperformancegarage.com/collections/fuel-system-kits/products/fpg-bnr32-fuel-pump-hanger-kit-single-fits-stagea-c34-nissan-skyline-gt-r-r32-fpg-087?variant=42131478315186

Because according to their video the low fuel warning thing can be taken from the OEM hanger and attached to their new hanger.

Just wondering whether this is the kit you weren't happy with, or whether it's a different revision.

Thanks again!

[Duncan]

Looks like they've been through a few versions of the kit; that is not the one I had trouble with (it had the level sender attached to baffles on the floor, the one you linked the level sender is hung from the hat).

One obvious point about that kit is it has no baffles at all, not even the factory setup (although it looks like you can retain the factory setup if you want).  Not sure if that will be an issue or not, the good news is it looks like you can get the pump nice and low in the tank, but that doesn't help if the fuel is all sloshing to one side of a wide flat tank

[soviet_merlin]

Okay, good to know that it is not the same kit.

There is no baffling in the tank from factory either, no? Possibly Nissan worked against that by feeding the fuel return line back into that little shoe the fuel pump sits in. From what I remember the FPG video mentioned that can actually be problematic if done with a high flow pump. Because the fuel is returned with more pressure through that little spout.

There are so many ways to overthink this. It does my head in. I'll see what Unigroup says as well and go from there.

It's a shame that the difference between the simple hanger and surge tank setup is ~$700. Add the new lift pump purchase on top and it becomes a bit hard to justify for a car that doesn't see that much action. First world problems I guess.

[GTSBoy]

Yes, well, the problem being the plastic tank.

The RWD R32s obviously have a similar tank, but in steel, viz

and you can see a nice sheetmetal swirl pot baffle. I would imagine that that is somewhat harder to do on a plastic tank.