joshuaho96

The front of the balance tube is the correct port to use for the fuel pressure regulator. It should only go to the FPR and nothing else.

I knew it was an R33 GTS25T because he posted the same exact question on a Facebook group but whenever possible I prefer to reply on something that isn't an information black hole.

It is basically a cut down version of the ATTESA ETS Pro system so yes it will be under the center console. The R34 Skyline manual throws all of the ATTESA/ABS/traction control diagnostics into the same section of the service manual.

The sensor is expensive so I recommend diagnosing first. Start by checking you have power to the sensor. If it turns out the 8V supply to the sensor is dead you're going to waste a lot of money to not fix your problem.

There's a g sensor under the center storage box that the skid control CU uses to modify the resulting lockup curve. Less lateral g and you will get more LSD lockup. More lateral g and you will get less lockup. From the skid control CU pin 40 is Vcc, pin 43 appears to be ground. Pin 41 is "Horizontal g sensor" and pin 42 is "Sidev g sensor". That's a horrific translation and I wish someone could just send me the original FSM in Japanese instead of trying to guess at what that means. Check the Vcc to ground voltage, it should be something like 8V supply and 2.5V signal voltage for both lateral and longitudinal signals sitting still.

That port with the bolt stuck in it is the port that the charcoal canister uses as a vacuum signal. I don't believe it is used to purge as there's another hose that is common to all cylinders rather than just the first two. As others have said it goes to that metal pipe which looks like someone has put it the wrong way. You can see the intended routing in this picture from when I tore the intake manifold apart: Personally I do not understand why people delete charcoal canisters on these cars when it is purely to one's benefit to not have raw gasoline venting into the engine bay and into the garage. Higher octane components evaporate first and leaving the gas tank open to atmosphere invites corrosion and moisture especially in the US where almost all gasoline has 10% ethanol in it.

The "skid ECU" is also responsible for controlling the Active LSD. Pull the codes from that module.

The front diff/steering rack leak area could be a lot of things. Could be someone spilled the contents of the oil filter all over the front diff as others have said. The other possibility is the o-rings on the oil cooler are leaking. There's two o-rings, one on the oil cooler itself to the oil filter housing, another in the eye bolt that bolts the cooler to the oil filter housing. If you don't want a huge project disassembling the whole intake side of the engine you can reach from below behind the front diff using extensions and wobble joints to get the socket in the right place to undo it. Then you get to fight the hose clamps that feed coolant into that heat exchanger. Another possibility is a valve cover leak but that should be obvious from the top of the engine if you look carefully. Another possibility is that the front diff itself is leaking oil from somewhere like the front cover or axle seal. In my case it was all three and I didn't know until I fixed one problem only to discover despite cleaning off the front diff and everything else I was still getting oil at the bottom of my front diff. I have started doing all my own work for these cars because I've realized that they aren't that complicated by modern standards (see: BMW N63, VR30DDTT, etc) and at the end of the day nobody is going to be as invested as you are in making sure the job is done correctly. Basically every time I have given the keys to a mechanic to let them do anything they have damaged something, usually discontinued and a huge pain to fix. Mechanics in my area are often used to being able to say that it could've been any previous mechanic that caused a problem but I am doing all my own work so often that I can pin down exactly who did something and it has turned into a huge fight every time I confront one about something I'm almost certain they did.

https://upgarageusa.com/products/skyline-gtr-oil-filter-relocation-kit You could mount the relocation like this instead of the normal location that Greddy's kit is meant to be installed in. Then it's really easy with zero mess. Send Cut Send is super easy for laser cut/welded parts if you can take measurements and do some CAD. Personally I am lazy and I realized with the R33 that doesn't have a bunch of HICAS crap fighting for space down there just spacing out the oil filter a little further is probably good enough.

You don't even need aftermarket ECU/Nistune, the factory ECU and R35 coils will not misfire if you're within the bounds of the stock tune. Someone local to me has tried this and he did not have misfires with the stock tune and R35 coils before switching to a Link. He did have a no-start but it was due to horrendous fuel pump wiring and possibly a dead fuel pump.

My vote is either the Nismo or HKS oil cooler kit. Personally I do not find the oil filter location to be that bad other than the mess of oil that spills out when you go to remove it but you can fix this with a form-a-funnel to direct oil the right way.

Apparently the coolant feed really does come from the block? At least if this photo is anything to go by: The EPC says it comes from section 110 which is the engine block. And the return seemingly goes around the back of the head to the hose barb at the back of the intake manifold which is not something I was expecting.

https://nissan.epc-data.com/skyline/er34/3944-rb25det/engine/144/15192P/ I can't tell where the water piping is meant to go but it appears to me that the water feed is from the block.

WTF does that even mean? Is he talking about the deletion of the idle switch in favor of voltage-based idle detection? All standalone ECUs to my knowledge ignore physical idle switches. If you want DBW to be worth it just add cruise control and traction control to the tune, maybe DBW-based rev limiting to get a no-compromise soft cut while you're at it. There's more you can do but those three alone are pretty big headline features you can do "for free" that are kind of a disaster to implement on traditional cable throttle. In theory you can also implement tricks like automatic rev-matching too.

No, considering the stock timing at idle is 950 rpm at 20 BTDC. Something is wrong. Narrowing down exactly where it's coming from is important, then getting eyes on if you can. Double check your gauge reading against another oil pressure gauge/sensor. Anything shedding debris will normally damage the turbos first as those are the most stressed bearings. Then they start shedding metal in response which causes a cascading failure.

VCAM doesn't allow for cam gears on the intake. And never ever forget to retorque all fasteners to spec on the exhaust side, I've seen cam gears slip on the dyno and it usually destroys the head in the process.

There's a flapper door that is opened by that actuator that goes to the evaporator box: https://youtu.be/XTaPa7xoHXY?t=329 I need to replace mine come to think of it, I hear it whirring away all the time instead of properly opening/closing the door.

The idea is to shut off fuel injection before you hit 0 or even some lower theoretical safe value. The moment the sensor detects oil pressure is just lower than expected for the current RPM which could be induced by either the pickup sucking air or excessive oil temperatures thinning things out too much I would want to set a hard fuel cut back to the bare minimum rpm needed to limp to safety like 2500-3000 rpm. With the accusump in place nothing really changes. Oil pressure flatlines after a certain RPM for the most part so the valve can safely be kept open and at high RPM you aren’t waiting on the ECU to see the fall in oil pressure to act. It would just be shut below say 3000 RPM to keep the reservoir full unless it sees oil pressure falling below what normal operation would show. Even factoring the slew rate of the sensor and sampling latency of the ECU I really doubt you’d see the engine fully lose oil pressure before engine protection kicks in. And once it does the violence of hard fuel cut should be enough to get me to stop pushing the car which could be letting off on the brakes/accel/lateral g which would probably also help resolve the situation. And if it happens more than once in a blue moon the answer is to fix the issues causing it as you have pointed out, not just to continue band-aiding the problem with sensors and ECU workarounds.

This is true, but the list of things that I would need to repeat this for is long enough that I may as well use the E2500 I already bought. VCAM, PWM fuel pump control of a brushless pump, and flex fuel are things I really want to do. I plan on seeing if I can survive without an accusump first using just oil pressure sensing + hard fuel cut if it drops out, then add accusump + associated headache if I'm constantly running into engine protection for my particular operating conditions.

My grand plan is to start by blindly replicating the stock ECU map, then going from there. Hopefully it dramatically reduces the amount of dyno time required.

I'd prefer to have the accusump not try to empty itself at lower RPMs just because oil pressure at low RPM is lower. So I'd want to take measurements on the dyno/in neutral of oil pressure vs RPM, then set up the valve to trigger open if oil pressure drops some percentage below expected. I also want to be able to trigger the system from the driver's seat during engine start. Also in specific cases like if I slip the clutch and drop the engine near stall like 400 RPM it would be nice to have the accusump kick in to make up for the oil pump not making that much pressure. I know, but this is me we're talking about. Everything has to have strange constraints and be far more complicated/overthought than it needs to be. I don't want it in the trunk because running lines + having a giant container of oil hanging out back there is inconvenient/not really streetable.

I suspect this is where I'll end up, I'm just not a huge fan of accusump considering you need to use a standalone to make the most of it and it really doesn't last long. It's also yet another thing to fit into a tight engine bay but at least it can be laid horizontally.

Surprisingly they restarted production on those things seemingly and Nissan USA will sell you one for ~240 USD MSRP. Most online sellers will give you a discount over that too. P/N is 21305-21U2A. When I refurbed the oil filter housing it was far more expensive to get new so I sent it off to a government-certified facility for aircraft oil cooler refurb. I figure if it's good enough for the notoriously conservative FAA it should be fine for my car. I might pick one up just to have spares if mine ever starts intermixing fluids.

"Head drain" as discussed is really more a crankcase breather. So instead of dealing with the restriction of piping crankcase gas into your head and trying to get that out into the catch can you're better off going directly from the oil pan (or block? not sure how you'd do that) to the catch can. You want the breather to be high up above the oil level to try and as much air and as little oil as possible. Blocking the PCV means no crankcase vacuum can accumulate at part throttle. Not sure that makes sense in a street car. Someone local to me blocked his PCV valve and vented to atmosphere and hated the result. Oil mist venting into the engine bay + crankcase gases from this engine are pretty bad. If you ever open the HVAC to fresh air intake for any reason you're going to smell it. I've seen crankcase breathers added to the oil pan like so: Whether there's a better place for it on an RB26 I really couldn't say. I have never been able to really look carefully at a block and how it interfaces with everything else to give a better suggestion. Personally I don't want an external tank to package somewhere in the engine bay. That and yet another pump belt hanging off the nose of the crank is just too many headaches IMO. And for a street car a huge oil tank hanging out in the trunk is also no-go. What I'm proposing is what Porsche calls "integrated dry sump". I wouldn't call it that but it's not far off. It can work for maybe 200TW endurance tires on the track but no further than that. I wouldn't object to paying dry sump levels of money for a solution that isn't necessarily as capable but is better suited for low maintenance street use.

AFAIK even modern I6/60 degree V6s still have scavenge pumps running off the oil pump. VR38 has a scavenge section built into the pump, S55/S58 have scavenge pumps as well. Mostly running off things that are pretty well guaranteed to not have air bubbles in the oil return line though I think like the turbo oil drains. The BMW solution sits inside the sump somehow, it would be cool if someone actually capable of machining/mechanical engineering could figure out something similar. I'm guessing that it's easier for a pump to force oil back to sump than to try and forcibly pump mostly air with oil mist up and out of the engine. Apparently in the BMW scavenge pump is primarily used to pull the oil out of the corners of the oil pan and push it into the pickup. It could be overkill though, BMW rated that engine for 1.4g under braking and up to 1.2g lateral g continuous. I don't know if 1.4g is really all that necessary but a modern 200TW endurance track tire is right around 1.2g. It also only has like 6.5 quarts oil capacity so really not a lot of oil compared to some of the extended sump designs I've seen for RBs.