joshuaho96

I forgot to mention you need to make sure you have no power in the harness before you attempt to measure any resistances unless you want to short out your multimeter and potentially damage both the multimeter and the control unit. Measure voltages of every pin relative to ground before you try to measure resistance. They need to all be 0V before you try probing resistance to ground.

Depends on which ones are monitored. Any monitored cat deleted will trigger a catalyst efficiency code. Also worth mentioning on modern cars the post-cat O2 is actually used for fuel control, when recovering from DFCO they look for the fuel to hit the post-cat O2 before they pull out enrichment. I personally refuse to ever work on decatted cars because the exhaust is so unpleasant to be around.

Presumably what they're actually trying to say is they deleted the catalytic converters and they want to disable the codes.

I would definitely try hard to get an aftermarket sensor to work if you can. A new OEM sensor is 1.6k USD which is absolutely insane pricing. Of course I would also recommend making 100% sure it's a dead g sensor to begin with.

Unplug the g sensor, use a multimeter in resistance mode and see which pin has zero resistance to the chassis. That will be a ground pin. Switch the multimeter to voltage and reference the other pins against the chassis. One pin will be 8V and the other should have no voltage as you haven't plugged it into the g sensor. If you can't find 8V anywhere then it's a power supply issue. Then plug it in and try to probe the backside of the harness pins if you can to see if you get 2.5V relative to ground.

Yes, that will work. But if you connect things like this you want to make sure the canister is also connected properly.

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.