Slartibartfast

My RMS needs doing too! It used to be a slow leak. 1. No special tools needed AFAIK. You can get the '90 factory service manual from cardiagn.com. The AT section has step-by-step instructions for dropping the tranny (AT-124), and the EM section has the same for doing the rear main (EM-20). 2. The gasket in the aftermarket kits goes between the retainer plate (which holds the seal) and the back of the engine block. Unless you're going to try and fish the seal out without removing the retainer, you'll need the gasket as well. I think I've got the Fel-Pro kit on the shelf for mine, don't remember--and of course I can't vouch for it as I haven't installed it yet. 3. I assume you'll need the gaskets for the exhaust crossover as well. You may need hardware or more depending on how much the exhaust fights you on its way out. These also tend to break exhaust studs (holding the manifold to the head), though I don't know that having the trans out would make these any easier to access. I would check breather hoses and exhaust hangers while you're under there. Might as well change the fluid in the transfer case too. 4. The trans cooler is a good idea. There are a few old threads on here with size and type suggestions. I don't actually know what mine's rated for, I got it secondhand and it's not marked. I installed mine in series with the existing cooler in the rad, and also added a Magnefine external filter while I was at it. If you just drain and fill, you don't get the old fluid out of the torque converter, so I did a flush through the cooler lines instead. Take the lines off the existing cooler, put them in a bucket, run the engine until fluid stops coming out, add that much fresh fluid to the transmission, do it again, repeat until what comes out looks more or less like what goes in. The trans fluid level is a bit of a pain to set. It has to be warmed up when you check it. If you set it cold, it'll be too high once it warms up. Either measure what you take out and what you put in and make sure they're the same, or undershoot a little so you have room to top it up once it's warm and you can check it properly. I thought mine was underfilled, warmed it up, and had to drain a bit back out of it. The manual calls for Nissan-Matic D, which is still available. From what I've read, it's basically just Dexron III, so I used generic parts-store-brand Dex-Merc, which was cheap and available locally. 5. Torsion bars are also a pain to set up. If you have to drop the bars (and the service manual suggests you will), mark, measure, or at least take a picture of where the adjusters are set and how the bars are clocked vs the adjusters. Otherwise you'll be screwing around for a while trying to get your ride height back where it was. I used spray paint to mark the adjusters on a friend's S10 Blazer when we swapped the trans, and reassembly was as simple as matching up the paint marks. This thread recommends filling the gap between the RMS retainer and the pan with silicone to stop mud from getting in there and causing corrosion. Seems like a good idea. Good luck!

The FE section of the service manual has diagrams of the exhaust system, and where all the mounts are. There's one between the pipe before the cat (off a U bolt in the '90 manual, off the cat flange in the later manuals) and the transfer case, one at either end of the muffler, and one on the tailpipe behind the muffler. You can get the '90 manual from cardiagn.com, or at least that's where I got it. I had a similar rattle on mine. It worried me at first, because it only happened under certain load conditions, making me think a U joint or something was on its way out. I found it by rolling under the truck and just whacking the exhaust with my hand until I found something that rattled. IIRC it was that U bolt upstream of the cat that had worked itself loose. The nuts wouldn't move, and the only problem it was causing was the noise, so I tied it up with baling wire and called it good. Given the crossover pipe has been out recently on yours, I would look especially hard at the fasteners and heat shields on that guy.

Damn! At least it's fixed, I guess. Hopefully it stays that way.

EF&EC-88 of the '94 manual has the correct diagram. All that tells me is that the vehicle speed sensor is wired to the cluster, which is then wired to the computer, so an issue at the cluster would stop signal from reaching the computer. It says nothing about how it's wired inside the cluster, where the issue presumably is, if the speedo works and the odo does not. Annoyingly the description of the sensor (EF&EC-15) is copied from the square-dash manuals, and shows the older arrangement of a reed switch in a mechanical speedo, not an electronic speedo with a sensor in the transfer case. Guess they missed that when they updated from the square dash! Wonder how many people that's tripped up. I did notice the round-dash cluster from my parts car (which I was told had an inop odometer) had cracked solder joints where the little stepper motor for the mechanical odometer was connected up. By the time I noticed this, the parts truck was torn apart far enough that I couldn't test the resoldered cluster, so I can't be certain the cracked joints were the only problem. But yeah, if it acts up again, that's where I'd start looking. IIRC I had to tear it down all the way to the instrument itself to find the fault--it wasn't on the flexy board on the back. Bit fiddly to get the cluster apart, but doable. Be real careful with the clips, especially for the clear part.

Hell yeah dude! Good to see you got it going.

That's bizarre. That much oil had to be going somewhere. I don't suppose you've got a mechanical oil pressure gauge under the dash, and a big black puddle hiding under the floor mat? Sounds like a good excuse for an upgrade, though! Hopefully the KA stays happy.

I've heard of alternator diodes failing and causing a draw that doesn't show up when you're pulling fuses from the box in the cab. I would try pulling the 120A fuse "A" in the "fuse and fusible link" box, which should be under the hood. If that doesn't drop the number on the meter, I would also pull fuse 65 (7.5A, same box) on the off chance.

Does yours have the cable throttle, or the drive-by-wire? I'm assuming cable given the drive by wire doesn't have/need an idle valve. If it is drive-by-wire, be careful cleaning the throttle body--I've heard of them going into limp mode and refusing to come out again if the computer notices a sudden difference in air flow. If it's the cable throttle, the IACV has a common issue where it leaks coolant internally, shorts itself out, and blows out the driver mosfet in the computer. Something to look into and check on while you're in there. Some info on that in this thread.

ECCS is not a separate component, it's just what Nissan called the whole engine control system (computer, injectors, sensors, the lot). The "ECCS control module" is just the ECM. There's an ECCS relay, controlled by the ECM, which sends power to the injectors, the cam position sensor, the MAF, and one of the evap valves. That diagram's on EC-11 of the '97 manual. I don't know what model/year your donor is, but the '02 Xterra diagram looks quite similar, except that they renamed the ECCS relay as an ECM relay, and it doesn't control the injectors anymore. IMO the deciding factor is gonna be how much stupid stuff like that Nissan changed between the two computers. Compare the pinouts in the service manuals. Hopefully they're close enough that you can get away with a little repinning. Maybe steal a few pins from the donor connector to get that boost solenoid hooked up. I remember My1Path doing something similar to put an M30 ECU in his WD21, but I don't think I've heard of anyone doing it on an R50, so you may be the first pig through this chute. If they're stupid different, or the connector itself is different, or you're planning to hot rod the engine past the donor's original power, then the Megasquirt might be the way to go. My personal favorite is Automatic Speed Control Device, aka cruise control.

SMOD was an R51 thing, shouldn't be an issue on the R50. It sounds like the valve body may be acting up, but I'm not an auto trans doctor. Any codes? The AT section of the service manual (free download from Nicoclub) might help track down what you're up against. Closest to a bolt-in that I'm aware of is the manual swap. Lock recently did a write-up about all that goes into that. I haven't heard of anyone swapping in a later auto trans.

I suspect that 40254-32G00 is correct for manual hubs (as it's the only PN listed from the lookup # for manual hubs), and 40266-50W00 is correct for auto hubs, and someone balls'd up the data entry and listed it for both of them. But this suspicion was based partially on the listed year ranges and my assumption that the W/D22 did not come with auto hubs, which it turns out they did. The diagram for an '01 X shows auto and manual hub options, and lists 40254-32G00 for both. I would then assume that the two bolts are the same... except that this post says they're not. I removed auto hubs from my '93 and my '95, and I don't tend to throw bolts away. If you break one, and strike out locally, let me know and I'll see if they're still hanging out in my bonus bolts drawer. FWIW, I was able to get all the bolts out of mine without breaking them, though it did take some heat-and-beat on the '95.

Yeah, that makes sense. Have you tried with the engine running? Nico's manuals stop at '16 unfortunately, but there is a description of the trailer lighting system on EXL-12 of the '16 manual, and wiring diagrams start on EXL-94. Might get you started.

I don't know crap about the R52, but I did spend entirely too long troubleshooting a trailer wiring fault on my mom's Lexus that resolved itself when I turned the ignition on. I guess it's got a powered trailer light controller? Something to check if you've been testing with the key off.

AFAIK, no. The only time I've heard of exhaust studs and coolant in the same sentence is when someone goes to drill out a broken one and misses.

IMO better to pull the upper cover off and get a proper look, than to drill a hole and potentially drop a bunch of swarf into the belt so you can squint at a screen.

I am a little confused on what you're trying to achieve. Are you looking for something in particular, or just keeping an eye on things? +1 for a grommet if you do start making holes. My dad's Tundra had an open hole in the timing cover (previous hack lost a grommet), and a mouse got in. It turns out skipping two teeth is not enough to kill a 2UZ-FE, but making one skip two teeth is absolutely enough to kill a mouse.

The bearings go bad. I took apart a failed dizzy from an Xterra last year. The upper bearing had ground itself to dust.

My spare IACV looks about like how you described yours. Half open at room temp. I connected 12v across the heater, and ~5 minutes later, it closed up. Left is cold, right is after powering the heater. I didn't try the freezer test, but the cutout does look like it should open a lot more than it is at room temp. Injectors would make sense. I've got one or two marginal ones on mine. One crapped out entirely once, consistent misfire, tested open circuit, then came around the next day and worked like nothing happened. It's been working since, so I haven't gotten around to replacing it. But I have noticed a little stumble from time to time, which I suspect is related. You can check all six injectors from the harness plug on the passenger's side valve cover. Of course that'll only tell you if the coils are good, not whether they're plugged up or spraying weird. But it's a start.

I'd say you found why the last guy sold it! Now that it's self-healed, you may have an uphill battle trying to track down the problem. The first thing to do is check it for codes. No way you lost drive and power to the dash without it setting a code somewhere, and that'll give you a lot more to work with than you have now. Do that before chasing any of my speculations below. (Also keep in mind that I don't know the R51 for crap. This could be a common issue that I haven't heard of.) Without codes, I would start by chasing the overcharging issue. The starting/charging section of the service manual shows that the alternator is controlled by the intelligent power distribution module, which takes orders from the ECM, which watches a current sensor on the battery ground cable. So that's narrowed it down less than you'd hope. Given you're having power distribution issues, and the truck has a power distribution module, I'd be suspicious of the IPDM. This guy reckons the early IPDMs have bad solder joints and do weird stuff when they crap out. Naturally he's selling IPDMs, so, do your own research. If the alt loses its signal from the IPDM, it's supposed to default to its internal regulator, like an old-school non-computer-controlled alt. The regulator in the alt could be bad, but that wouldn't explain the other issues. I would also have a look at ground cable on the battery. That's where the sensor is for the smart alt, and bad grounds can cause all kinds of weirdness besides.

Check your trans fluid level. The fluid level rises slightly as it warms, so if it's very low, the pump might be sucking air for that first 5-10 minutes, until the fluid gets some heat in it. I haven't seen this on a Pathy, but I worked on an S10 pickup with similar symptoms. Drove normally when warm, slipped real bad when cold. The trans fluid was super low, and smelled burned from the slipping. Fixed the leak, fresh fluid, and it was fine again. Hopefully yours bounces back as easily. There's a procedure to set the trans fluid level. Warm it up, park on flat ground, run it through the gears, check it with the engine running, add fluid through the dipstick tube as needed. At least that's how I remember it. Download the AT section of the service manual from Nicoclub, it'll have the instructions. I'm not sure if yours is an R50 or an R51 (IIRC the changeover year was different in your market?), so make sure you're looking at a manual for the correct chassis, not necessarily the correct year. If it's got a solid rear axle, it's an R50. I'd use the '04 manual. If it's IRS, it's an R51, so use the '05. If the fluid level and condition are OK, check it for trouble codes. The computer should have some idea of what's wrong. The AT section of the service manual also has troubleshooting for each code. The manual assumes you have dealership-level scan tools, but there's usually a workaround or a "without Consult" option in there somewhere.

It does make sense that a low idle when the engine is cold would be giving you issues. The high idle is there for a reason. But I assume you didn't smog it cold, and I would expect it to clear up as the engine warms up. It's supposed to come off high idle once it's warmed up anyway. Maybe the computer could be doing something weird if it's letting little or no air through the AAC due to the IACV being stuck open, with the idle still above its target? Maybe someone somewhere down the line meddled with the idle screw to try and mask the bad IACV, and that's making it worse? I still wouldn't expect that to manifest as a misfire under any condition but cold idle. In any case, it does sound like you've found something wrong. Absent any other smoking gun, might as well chase that one, I guess. I have an IACV on a spare plenum. I have no idea if it's good, but if you want I can pop it open and see if it's how you describe yours or not.

EF&EC-14 explains how the idle control components work. The plate in the IACV (the tall one that sticks up) opens when the engine is cold to raise the idle speed. There's a heater inside (that's why it's got the electrical connector) which closes it over time. If it was bad, you would either have a high idle all the time (stuck open), or no high idle when cold (stuck shut). I don't know how much it should open and close from external heating/cooling (surely the heater inside is more effective), but, yeah, if yours is mostly closed at room temp with no power going to it, that ain't right. I'd expect it to be wide open when cold unless it's gunked up or the bimetal that moves the shutter is broken. The IACV-AAC (the one built into the block with the idle adjust screw) is the one that's pulsed by the computer to do the fine-tuning. I'm not sure why there are two valves for the same function. Maybe it was easier to add another valve than it was to add another function to the computer.

No worries! Sometimes the service manual buries stuff in weird places. Good luck with it, hopefully it's not the sending unit.

There's a window lockout switch on the driver's switch panel. Make sure that's not engaged. I'm not seeing a relay in the power window circuit (BF section of the service manual), but there is a circuit breaker that could give you issues. Looks like it's behind the driver's kick panel. Not super far from the flasher, but probably not what you unplugged by mistake.

Look for vacuum leaks, and check the tube from the throttle body to the airbox.