joshuaho96

Pull codes via the self-diagnosis procedure. As far as I can tell this is just a sign of transmission issues but not a code unto itself.

Sounds like a misfire. Check fuel pressure and don't even think about going into boost while it's like this unless you enjoy engine rebuilds.

The average previous owner for these cars were basically S-chassis owners in the US. Teenagers or teenager-adjacent. I often tell people that neglect is easier to fix than something that was actively "repaired" by previous owners.

I've heard the Tomei USA head gaskets are decent if you want to o-ring the heads but otherwise not recommended.

Drain it. I got official Matic D but you can get whatever is listed as Matic D compatible.

The incentives are mostly the same, yes. Ethanol is cheap compared to the cost of doing 98-100 RON with crude oil alone. 87 to 93-94 AKI all with E10. In 2020 Canada mandated E10 as a part of their "renewable fuel standard" and is supposedly going to go to E15 in 2030. In California where there are only 8 refineries with two threatening to shut down next year it's been over 20 years now of E10 and 91 AKI maximum because there's just not enough refinery capacity or crude oil supply relative to the demand for premium unleaded fuel. And CARB's low carbon fuel standard means functionally none of the diesel available at the pump is made from crude oil anymore. It's almost all entirely 20% biodiesel blended with 80% renewable diesel (hydrotreated vegetable oil) now. The number of gasoline vehicles that support E15 or higher ethanol concentrations is surprisingly low, I can't imagine it being wise to play tricks like this without flex fuel sensors in most of the fleet.

In the US almost everything is E10. It can't exceed 10% by much or fuel systems have trouble adapting. At the same time because MTBE, MMT, and TEL are all banned they need as much ethanol in it as possible to boost octane.

E10 is pretty tightly regulated in percentage. Too much and engines can't adapt. Every incentive is against them to have too little ethanol though. The more ethanol the higher the octane.

The other reason why I say this is because if you lose the motivation to mess with this stuff, at least if you can get the car back together and fixed up better than it came to you usually you can sell it for more than you paid. Skylines in that regard it's pretty rare for anyone to actually come out ahead.

My recommendation is start with maintenance. Find a ~15 year old car that is cheap for a reason and fix it up. For example, in my area F30 328i with N20/N26 are dirt cheap because everyone knows that the timing chain loves to stretch and take out the cylinder head around 80k miles. Buy one, do all the maintenance on it, if you're still motivated after that an N20/N26 can be easily modified for more power.

It's sodium citrate, I misspoke earlier. It's a citrate buffer solution. And yes, depending on how thin the metal in the tank is this may or may not be a wise decision but if it's just mild rust it should clean off and it should be fine.

You can probably scrub the rust with a toothbrush or something. After you get the rust off flush well with water to neutralize and you will probably want to also use a fuel tank sealer to keep it from rusting again.

The sodium citrate solution is designed to buffer the citric acid to keep it from attacking metal quite so much, the guy that came up with that recipe did a ton of testing on how much metal loss occurs over time and it's nothing crazy unless you forget about it for months:

Yes, it will take a fair amount of solution but the sodium citrate + citric acid + detergent is cheap stuff. Use laundry detergent instead of dish soap if you want to reduce the bubbles, also you could just buy sodium citrate and add some citric acid to the mix until you get to a weakly acidic solution if you don't feel like dealing with all the bubbling generated by adding everything together. For a fuel tank you need quite a lot of distilled water but it's probably worth the effort.

Take the fuel pump out of the hanger, purge the fuel tank of gasoline, try cleaning it with a soaking of this sodium acetate and dish soap solution. If there's no rust holes this should get the tank and hanger clean.

Not only should you be testing compression with a strong battery, you should be putting a charger on it. These cars have pretty small batteries and it's possible to discharge them enough that by the last cylinder the starter isn't turning as fast.

Hard to say, just pop the rocker covers off and have a look if you think it's cammed. You probably need to replace the valve cover gasket/half moons anyways.

Would the new Haltech Nexus plug-ins work for this? Or are they actually checking under the kick panel?

As soon as the MAFs are replaced with ones that work properly, if the harness isn't ruined it should run perfectly immediately.

Do a degree in mechanical engineering specializing in combustion systems and materials. Learn how to actually wrench on things that don't require 70k+ USD buy-in while you're at it. You also want to learn to weld and machine. If you still want to do this then you'll nominally have the knowledge to actually do what you're thinking of doing. Whether you still want to do any of that once you've actually gone through that process is anybody's guess. Personally I cannot imagine anything more frustrating than trying to package a supercharger under the hood of any of these cars when the turbos are already fighting for every last inch.

Join the NorCal facebook group btw, but if you can confirm it is HICAS I would install a lock bar and do the work to keep the HICAS control unit happy despite the hardware not functioning. The HICAS control unit is also responsible for speed sensitive power steering so if it's unhappy you'll get failsafe/heavy power steering. A standalone can control that power steering solenoid valve but sometimes it's just easier to stick with the factory setup. Tomei makes a little electronic module that you can install to fool the control unit. I would probably go through the effort to not use a scotch-lok and build a harness so I don't have to chop up the OEM harness. Where you could source those connectors and pins I wouldn't know at the moment though.

Probably speedometer itself if the odometer is ticking. If the needle is stuck from a bit of grease or something that can cause it to stay at 0. Or a cracked solder joint in the speedometer can do it too.

You're not wrong but 5W30 at 100C is like 10 cSt vs 25 cSt for 10W60. If we think in terms of viscosity margin 10W60 will probably still be ok at 130C but 5W30 is probably too little. It's absolutely shocking how hot the oil gets in something like a stock FL5 from only ~3 minutes of use on the Nordschleife. I would not risk taking a car like that to anything remotely intense without a ton of work done for cooling. Heat shielding on the manifold/turbo/downpipe, oil coolers, etc.

Sounds like the rack seals blew.

ZF8 is faster, wider ratio spread, better in every way. I do not dispute this. But I have brain damage and I want the feeling of shifting gears. To me the extra work is fun, but I daily an automatic and in the US like 90+% of cars are automatic so a manual transmission is an "exotic" experience. If I want an automatic I've driven an F80 M3 with DCT more than a few times and it's incredibly capable but it's emotionally vacant to me.