GTSBoy

Well, now you can look to test it by getting it warm, then stopping the car. Then disconnect and block both the hose and the IACV to prevent any air going through it. Start it back up and see if it goes quiet. You might need to open another vacuum leak into one of the small ports on the plenum to give it enough air to idle. You could attach a length of hose to that to take noise of that leak away so it doesn't interfere with the experiment. If you find that the noise was an internal air noise. You might try to clean the cold start valve part of the IACV a bit more. Otherwise, rather than replacing the IACV, I would convert to Haltech and e-throttle as much better alternative, fully justified by the failure of the IACV!!!!!

I meant internally. The cold start valve is a deliberate vacuum leak (from a certain point of view). It's not a "problem" vacuum leak, because it is drawing filtered and metered air. What I mean is that the valve might be not closing properly, leaving a small opening that makes a noise, like a whistle or a trumpet, as the air gets pulled through. The air is doing near sonic velocities while going through. Small holes can be exceedingly noisy. I thought this might be the case because the noise is clearly not the motor having an electric fit, if the noise continues when you unplug it.

Sorry, without context..... I meant the above to follow from

Oh, then it is probably a vacuum/flow leak associated with the air path through the cold idle valve.

Video is not helping. Sounds like an engine. The IACV will not respond usefully until the coolant heats up enough to close the cold fast idle circuit. At that point the IACV will be able to start to control the idle speed. So it's not surprising that you hear nothing until 70°C, because up until then the IACV is probably driven hard up against the closed position. For all I know, the IACV always makes some noise. Is this a new thing? How loud is it really? What does your ECU tell you (via Consult) about the number of "steps" that the IACV is operating at, below 70 and above when it starts making noise?

Maybe. The factory manifold doesn't have a lot of science in it, so I'd be reasonably open to the possibility of a well designed high mount manifold meeting or beating the spool performance of the stocker. You probably wouldn't be able to have large diameter runners. They'd probably have to be kept at the skinny end of the workable range. Smaller diameter runners would also help with keeping the runner lengths down too, as you wouldn't be building out of such big bends. Probably a self defeating exercise to do all that for a small runner low power high mount manifold though!

You don't even need a drill. Just cut a strip of sand paper (or even better, stropping tape) wrap around one side of the commutator so that you're holding both ends of it towards you and just do the old back and forth on both ends. Wiggle them up and down so you strop more than just the far side. Then rotate the armature (your assistant, or the vice, however it is being held) a bit and keep going until you have done an even treatment all the way around. Don't try to deglaze each spot all at once. Better to treat it like doing light coats of paint and go around and around a few times. If you use a hand drill to spin the armature, be very bloody careful. One slip and you can make a mess of yourself. If you use a drill press it will be easier and safer, but still a little prone to risk. A lathe is one step better again (and how proper reconditioners would do it).

You want to replace like for like for originality's sake? I wouldn't. There's nothing special about the Nismo KYBs. Bilstein B6s for stock format, or proper coilovers for betterness all around.

That commutator does need to be cleaned. It is very glazed. You need to make sure that there are no bridges of conductive material between the commutator's pads also, especially if you machine/shrop the comm. Those brushes appear to be ~50% worn, or more. They might not have enough tension to make reliable contact with the commutator, and the fact that they are so short and are sticking out of their recess so far is probably the reason why they are worn on an angle. I'd suggest it needs new brushes.

My solution to this was to get some of the grille mesh that you can buy from Autobarn etc (although I actually used some metal gutter guard from Bunnings) and make a piece to fit on the back side of the oil cooler. I put it on the back side and bent it to cover the sides also, for paranoia's sake. The bend around made it easier to attach too, although I can't remember exactly how I attached it and I can't go look until I can go home, which will be....next year.

Listen to these two ^. They speak the truth.

Per month, across 15 years.

We also need an e-penis.

Yes. Finger/mind fumble.

Dude. What's the diff got to do with HICAS?

But for all practical purposes, they all have HICAS, because no-one bought any of the models that didn't have it, and certainly no-one imported any (to Australia, anyway). FWIW, converting to non-HICAS is not that hard. Can either just put in a delete kit (better than a lockout) or swap in an entire subframe from a non-HICAS car (I put an A32 Cefiro subframe into my R32).

1% difference was between the 3 sizes clustered around 444.

Well, they're not 480, and it wouldn't matter if they were supposed to be 440, 444 or 448, as <1% difference is far smaller than the random tolerances anyway. As to the dead times.....dunno. But the part numbers are well known and I have seen very good tables listing all Nissan injectors against part # and specs, which I', not going to google up now.

Either remove everything from the engine bay, clean, detail and polish everything, then reinstall, and never drive it again, OR Just leave it mostly dirty, give shit a bit of a wipe off every now and then and just enjoy driving the f**king thing.

Well, you can replace the cam caps and hone them. But you can't just go buy them from the shop.

They could be good, or they could struggle. I'd be worried that they're not good enough. It's not as if Splitfires are actually any better than brand new OEM coils. They're just the same technology level, well made. This would be my approach to anything above 400kW these days. Eliminate the possibility of trouble. 8 is probably wise. I would want to be running fu(k tons more than 0.6mm gap. That's sufficient argument for R35 coils straight away.

It's because it is the easiest to see and touch. Do not underestimate the laziness and stupidity of your typical Skyline modifier.

Not the smartest place to interfere with the vacuum lines because if you manage to have a problem (ie, it falls off/open) you get uncontrolled boost at the same time that you don't get boost referenced fuel pressure. Ideal for rapidly beating the engine to death.

He'll hate me for it, because he doesn't like dirty Renault motors, but take it to Fours'n'more. He'll take a proper look at it and hopefully work out whether it's a buggered lifter, VCT solenoid/actuator, timing chain guide, f**ked bottom end, etc etc. They're at Pooraka, but that's only 15 minutes up the road.

Almost certainly won't fit at the front Z31 has very low height at the front of the engine bay. RB30/2Xs already don't fit in R32s without chopping stuff (bonnet ribs) where the timing cover hits. I don't have any problem with you wanting to put a 3L in there....I just think that a V6 would likely be the sensible choice, as horrible as that is to have to say. But, if you do go RB30, don't f**k about with RB26 head. Let some other Yank pay GTR tax for that. Use the better RB25 Neo head. Internet points for RB26 are nothing compared to better actual performance.