joshuaho96

Does it do that when you're cruising at say 60-70 kph? At idle it will bounce between 20 and 80 for some time before finally getting too cold to read and going down to roughly 0 and staying there even when the engine is fully warmed up. O2 will start sluggishly responding around 30C coolant temp when you're driving around as well.

There's almost nothing in the ECU that is operating in closed loop fashion during cold start. Crack it open and see if you have any dead caps.

Rockauto has it listed for 60 USD: https://www.rockauto.com/en/moreinfo.php?pk=1644542&jsn=724

Check oil pressure yourself. Supposedly it can just be the solenoid failure and the gallery gaskets are actually fine.

I doubt any Skyline still running 10 years from now will actually matter for emissions.

The information asymmetry and resulting disasters I see is pretty bad out here.

Sell the car and buy something optimized for lightweight. You could replace all the body panels with dry carbon and only save maybe 140 kg while spending more on those body panels than the car itself. To actually reduce weight requires a complete rethink of the chassis, not window dressing. Look at how Lotus did it in their Elise and you have some idea of what it means to substantially reduce weight.

https://www.rockauto.com/en/moreinfo.php?pk=2656930&cc=1430921&pt=5416&jsn=886 https://www.rockauto.com/en/moreinfo.php?pk=2647470&cc=1429567&pt=5416&jsn=1004 Only difference is the A at the end. In the US the non-A version is listed for 2000-2003 Sentra and the A version is 2002-2006. I have a very hard time figuring out what the difference is just looking at the pictures at a glance. I have a hard time telling what head bolts can be trusted but TTY requires a new set every time. OEM in the US at least seems really cheap for head bolts, if it's only a few dollars each way I would just go OEM to not have to sweat it. Even then sometimes I just end up going OEM in cases like the RB26 oil pressure sensor where all the aftermarket alternatives are notorious for dying rapidly.

Mahle makes a head gasket kit for these engines, I'd probably go with them. The specific kit varies based on the series of the engine. They're on the expensive side for aftermarket but dramatically cheaper than OEM. On Rockauto though they have a set that is heavily discounted down to 30 USD before shipping for USDM Sentras built after 04/01/2003. Normally it's 85 USD. Nissan wants 80-90 USD for the head gasket alone so I'd call it a deal.

Interesting, anything you'd like to say in detail?

I personally value the parts that a VSpec gets because I have no plans to actually modify things like the suspension or rear diff. The question you're asking is how many people actually value those parts. Judging by how often these cars have aftermarket diffs and suspension all that's left is two underbody covers basically. Value is relative. To some people the mechanical diff is actually preferable in the base model because it means no A-LSD errors or other nonsense to deal with when you rip out the factory A-LSD found in a VSpec.

If actuator preload doesn't fix your problem it's possible that there is excessive wastegate bushing wear which will require pulling the turbos to fix. Not sure if that's a common issue with these cars though, it's mostly notorious in the BMW N54 turbos for whatever reason.

It's swings and roundabouts. Doesn't matter that much. The earlier VSpec 1 has slightly better undercoating from the factory, the headlights still have the level adjustment motors, small touches like that. Series 2 base model gets slightly improved brake bias. Focus on condition. Only worry about VSpec vs base if you actually care about the bits that come with the VSpec like the front diffuser, rear diffuser, A-LSD, and slightly stiffer OEM suspension.

I'm surprised setting preload can be done on the car, factory service manual procedure has a specified measurement method for it and it looks like it has to be done with the rack out of the car. I had a tiny, tiny seepage coming from that adjustment and I ended up just ignoring it because I didn't want to mess with the adjustment at all.

Exhaust backpressure alone is not going to make you lose half of that spring rating. Anyways, if you really do have some HKS turbos in there you don't want to be running a lot of boost regardless. It's not that hard to max out the factory MAFs. Edit: We've had this discussion before two years ago, my answer still remains that you have some kind of mechanical issue. If you had a boost leak before papering over it by running max bleed on the wastegate vacuum line isn't a good idea.

The R33 GTR manual specifies 8.56 psi minimum to crack open the wastegate, purely spring pressure. It's not significantly different from the R32 GTR. Something was already wrong, it's just more wrong now. A 0.3 bar spring would only allow for a theoretical max of something like 0.6 bar boost.

I haven't measured the wastegate solenoid duty cycle but a local near me had something similar going on with his RB26 where the previous owner looped the wastegate line to atmosphere. It pegged the stock boost gauge. Once he capped the wastegate line so it no longer vented to atmosphere he ran wastegate boost. If you have any doubt that your ECU is not tuned for the turbos your engine is running you should run wastegate boost. The factory ECU has narrowband O2 sensors. It doesn't know anything other than roughly stoichiometric but it will adjust how much fuel it injects based on that information. If the short term fuel trims to hold it around stoichiometric are reliably offset in one direction that feeds into the long term fuel trim. If the long term fuel trims out are of spec that will tell you that you have some kind of running issue like unmetered air leaks. One broken turbo can lead to the engine make some boost. It will be noticeably less but still some boost. Also, if the turbo bearings let go from a boost leak you need to stop driving it sooner than later. Turbo failures often cascade into whole engine failures.

Definitely if you didn't have a screw loose already these cars will make it happen.

First, if you deleted your boost solenoid what is your vacuum line routing for the wastegate? I have personally seen people do the exact opposite of what they need to do to run wastegate boost when deleting their boost solenoid so this is an important question. Also I recommend checking for boost leaks starting after the MAFs. Second, what do your fuel trims look like? Long term and short term. If it's off by more than a few percent you still have problems. Third, have you inspected the turbos? Turbo failure can start with not making boost.

Good to hear you got it fixed. Sounds like a case where there was no one problem, just a bunch of issues all around. For reference in the future the way idle control works is the ECU is monitoring engine RPM and adjusts AAC duty cycle to suit. If you have some kind of vacuum leak that means the AAC can't adjust the idle properly then it falls back to pulling ignition timing out until it hits a limit. Once both of those methods have failed it basically starts cutting fuel injection momentarily to try and control the idle which causes that characteristic idle fluctuation. Idle drops from the fuel cut, then races back up the moment fuel injection resumes and the cycle repeats. I'm willing to bet if you logged injector duty cycle you would see the characteristic on/off behavior I'm talking about. The ignition timing going all over the place is likely a reaction to the engine RPM changing. There is some logic to try and catch a falling idle with more timing but once it gets too far from the target it will stop trying and hope for the best.

If there’s no coolant passage in the series 2 that really leaves very few if not zero possibilities other than head gasket. In 3rd gen Priuses head gaskets start by failing ever so slightly and causing a rough cold start as the coolant has to get burned off.

I took the time to stare at the technical data sheets more carefully, Loctite 518 is more tolerant of bad machining. Both are supposedly fine with a 0.25mm gap but 518 has a lot more shear strength than 515 in that scenario. Both have comparable engine oil tolerance but only 518 is specifically tested for ATF tolerance. 518 actually has less shear strength at 100C than 515 assuming you have that 0.05mm maximum gap. If the 515 fails to seal I would try the 518 and see if that improves anything.

I can only go off of the factory ECU logs but a pretty stock RB26 will warm up the coolant in about 400 seconds to 76C from 20C and another 60 seconds to get to 80C. So 6-8 minutes if coolant temps start at about 20C. Oil is probably 2-3 minutes behind, hard to time it exactly because I'm looking at a gauge instead of nicely time aligned charts sampled over Consult. Also, when the engine is warmed up the power steering idle up switch triggers a straight 8% bump in AAC duty cycle but when the engine temps are cold it's 7%. Not sure why there's this temperature dependence but that's what it is. I only park hard and hypermile my cars so this sounds like way too much effort, that is a really cool solution to the problem though.

Kind of surprising that they start with fuel cut to a cylinder, I would have figured adjusting timing within a range would be the primary strategy. Maybe that causes excessive EGTs?