Slartibartfast

Should be in the service manual, I'll PM you a download link for the '89.

What did the first mechanic do? Make sure the overdrive off switch on the shifter isn't triggered accidentally (don't figure you would've missed that, it's got an idiot light, but worth checking before diving deeper). I very much doubt it's the cluster. Is it shifting normally between the other gears? And when you first turn the key on, before you start it, does the light in the E-AT switch flicker?

Personally I'd stick to stock or very light tint on any window you want to see through at night. Tinted windows are like sunglasses, you don't want them at night (unless you're Corey Hart). The PO of mine tinted everything but the windshield and the sunroof. I don't know what percentage it was, but it was way too dark. It felt like I was driving a cave. I don't normally get claustrophobic, but, yeah, that crap had to go. I left the rear doors and the cargo area windows dark (can't see through those anyway), but swapped in a stock-tint rear window so I could see out the back, and stripped the front windows bare. I like the result a whole lot better. I don't know what the factory percentage is, but I would expect a place that installs window tints to have a meter they'd let you use, probably the same type the cops use. And yes, I would expect the % blocked to add up like that, assuming the films aren't polarized.

Never would've thought to check a Honda, good thinking!

No worries, and, yeah, I get not wanting to pull it apart again! I had a knock-down drag-out with my brakes a couple years ago and since then I haven't even wanted to think about brakes since then, but I know gonna have to open the system again sooner or later. Good luck with the California smog!

The CEL is supposed to come on with the other dash lights when you turn the key, so just cutting a wire or removing the bulb would be pretty obvious, and I'm sure it wouldn't be the first time they'd seen it. You could disconnect it from the computer and jumper it to another idiot light that you only see at bulb check, but if the mixture's far enough off that it thinks it has an injector leak, I'd expect the sniffer to notice that no matter what the dash says. I think you were on the right track checking for injector leaks. Better to figure out the issue than waste time (and hack up your harness) trying to hide the issue.

The symptoms (minus the smell) sound just like when the idle control valve on my '93 stuck closed. I like your zip tie bodge, I'll have to remember that one. The smell's not a good sign. Blown electrical components don't always fail in visually obvious ways, so I wouldn't assume the computer's good. Work out which wire going to the IACV is supposed to be switched by the ECU, then check for power there with a voltmeter to see if it's doing it. You might have to cycle the key or try to start the engine before the computer powers it up. Download the service manual here if you haven't yet. That should have the wiring diagram for the IACV and the TPS info you're after as well. If your scanner does live data, you can check the TPS with that too, just watch the throttle position as you slowly press and release the pedal and see if the numbers agree with where your foot is. If it jumps all over the place or has dead spots, the sensor is junk.

Bad valve cover gaskets can run down the back of the engine and look like the rear main is going. Not to say it isn't the RMS, just that I'd check the valve covers first. A couple drops of oil after you park it makes sense if something's leaking--it takes time for the oil that's leaked out while the engine was running to run down the outside and drip off. There's always the question of how much you want to do "while I'm in there." It's easy to go down a rabbit hole, but at the same time you don't want to have to repeat half the work later to get to the thing you didn't replace while you had it apart before. If the leak bothers you and the money's not an issue, go for it. The RMS in mine leaks a little, but not enough that I want to drop the transmission. That's not happening until the engine or trans gives me a reason to pull it apart.

You've got the same info I do, then. I'm confused that the pump would turn at double crank speed. I'd expect it to go half crank speed, in sync with the camshaft, like the distributor on a gas engine. If this is the case, it could well be possible to set it up backwards (with the crank 360° out, at top dead exhaust instead of top dead compression). I would roll the engine over until #1 is on its compression stroke, then see if you've got marks on the idler gear to match to the gear on the pump.

The '94-'95 FSM (free download from Nicoclub if you haven't already) will be more applicable to your truck than the earlier Chilton, but AFAIK the procedure to replace the CVs should be the same for any 4WD WD21. The thing that hung me up when I did mine were the stupid twelve-point bolts holding them in. I didn't have a twelve-point 12mm impact socket, so naturally I destroyed a chrome socket before borrowing the one I needed. I haven't found a torque spec for those bolts, but I didn't install them with a torque wrench.

I think I see what you mean. I assume that if there's a way to get it wrong, the service manual's procedure for setting it up would tell you how to avoid it (or at least give you a procedure to follow). Do you have the service manual?

If there was a good way to add subs for $50, there'd be a lot more people with subs! If your plan is to piggyback the subs onto the existing speakers, that's gonna be way more current than the factory amp was built to take. If you disconnect the stock speakers and run those wires to the subs, that might work, if the resistance of the subs is the same as the resistance of the stock speakers. If the resistance is lower, again, that's more power you're trying to push through a system that was not built for this. Maybe you could get away with one sub if you bridged the two rear speaker channels (connect inputs and outputs so the two channels share the load), but I still wouldn't expect much from it, and of course it would mean losing your rear speakers. If you get a proper amp to go with your subs, it'll want a line-level (not amplifed for speakers) input. On a proper install this would go to the RCAs on the back of the head unit. This is where the converter Colin linked comes in. Tee off the stock wiring, the converter drops that speaker-level signal back to line-level, to the amp, Bob's yer auntie. I'll bet you could tap into the line-level from the head unit to the amp instead, so you don't need the converter, but that would mean digging deeper and hacking up a part of the harness that would be more complex to put right if you wanted to go back to stock later.

The later Quest alternators are good for 145A, and Nissan Nut did a writeup on how to swap them into a WD21. Looks like they take a little screwing around to get mounted up, but Rockauto's got them for less than half the cost of the billet one. I've heard of people having belt issues with the Quest alt, but I'm not sure if that's because they didn't get the pulley alignment right or if that's just what happens when you ask too much of a V belt. I don't think I've seen a review of the RR alt. I remember someone complaining that the Mean Green had a stock regulator in it (presumably undersized for the rated output), but that was a while ago. I may upgrade mine to the 90A Maxima alt if/when it craps out. For now it seems to be keeping up just fine. If anything on mine is going to eat a stimulus check, it's probably the steering box.

I don't know the TD27 but the manual shows marks on the gear teeth for lining up the pump, so I'd expect 360° out to be exactly the same as what you started with unless there's a gear reduction inside the pump. No idea about the gear compatibility, sorry.

I remember having a "fun" time with those lines too. I usually use a little WD40 or silicone or something when hooking up hoses, but that's less helpful when there's nowhere to put your hands. Since then I got a pair of hose pliers (like needle-nose but with curved tips for hoses), sees like that'll make round two easier if/when I end up in there again. At least Nissan didn't use spring clamps that pop around backwards when the pliers slip.

Wikipedia says the R20 and R50 got the same generation of engine, with the same power output, so I'd expect the R20 manual to be pretty close. I have a manual for the non-turbo version used in a van (no idea why I have that) but I don't think I'd trust the NA specs in a turbo application.

+1 for doing a leakdown test first, and for considering a VG33 swap if the 30 has to come out anyway. 416k is a very respectable final score!

Yeah, do everything you can while you're in there. Cam and crank seals, water pump, thermostat, bypass hose, belt, and tensioner, and have a good look at your rad hoses. The timing belts last long enough that the chain conversion would be more trouble than it's worth. If you want a longer-lived belt, get a set of sprockets off a later (mid-'93+) VG to run the round-tooth belt. Square-tooth is good for 60k miles, round is good for 100k IIRC.

I did a little poking around in the service manual and I think I found it. Looks like the ABS runs a self-test after you start the truck, but it waits until you hit 4mph. "A mechanical noise may be heard as the ABS performs this self-test. This is a normal part of the self-test feature" (BR-30, 1997). Naturally it doesn't doesn't elaborate on what this "mechanical noise" is supposed to sound like. The buzz is probably normal. The bang kind of makes sense too--you're pushing fluid through the ABS when it's cycling its solenoids, figures it would make some kind of noise if it held and then dumped that pressure. That said, I have no idea if it's supposed to do that, and an unexplained banging noise under the hood seems like something they would've tried to avoid. You could check this theory by jacking up the back of the truck, resting your hand on the ABS block, and having someone start it and spin the wheels up to 4 mph to trigger the self-test. If it's vibrating enough to hear in the cab, I bet you'll feel it. Should feel the bang as well if your assistant makes it do that. Or you could just unplug the electrical connector for the ABS block and test-drive it, which should stop the noises entirely, though it looks like you'd have to do a code reset afterwards (instructions for that on BR-47). If the ABS light isn't on already, the computer thinks everything's fine, so, that's something. How's your brake fluid look? You could try flushing it on the off chance you flush some schmoo out of the ABS and quiet it down. I'd give it a couple panic stops too, see if you can make the ABS cycle properly. Maybe it just needs a little exercise.

I would check the U joints in your rear driveshaft first.

Your '97 doesn't have automatic locking hubs, unless someone went to a lot of bother to fit them. The R50s all had drive flanges from factory (basically a permalocked hub). I'm not sure what would cause this that would only do it once at the start of each drive cycle. Loose heat shields can rattle, but not generally one-and-done like that. Banging if you hit the brakes makes me suspect something in the brakes or suspension is acting up--maybe trying to seize when it's sitting, then chattering or popping free when you set off? I would check the brakes first, then have a look at the suspension joints. See if you can make the noise appear under any other conditions. I doubt the steering pump has anything to do with it.

I've got an '89 manual, should be the same. I'll send you a link.

Have someone push the body sideways while you watch the panhard rod bushings. The upper and lower links locate the axle front to back, the panhard controls side to side. If those bushings are roached (and they're the same age and presumably the same type of rubber as the link bushings that were roached), I would expect some side to side action. I would also inspect the panhard bracket, not that I've ever heard of one of those failing. The R50 is unibody, so the body can't really fall off, but they are known for rotting out in the front strut towers. There was a whole recall about that where Nissan glued crap over the rust holes and told people they'd fixed it. Worth taking a look at.

Impacts are great for taking things apart, but also great for screwing things up when putting them back together. The service manual specs 58-65 lb-f on the cam sprocket bolts. I welded up a tool to hold the cam sprocket while I tightened the bolt with the torque wrench, but I've read that you can hold it well enough with the old belt and vise grips. If the threads are okay, then yeah, I imagine it'll back out pretty easily once there's no tension on it. I ran into that recently replacing the water filter in the house. Turns out it's a lot easier to unthread the housing when it doesn't have 50-60 psi jamming the threads together!

It was a while ago that I did mine, so I don't remember, but I probably separated them just in case the pulley caused a clearance issue on the way out, or in case I dropped it, or to inspect the rubber part of the balancer. I don't remember bothering to separate them again when I took it all back apart to replace the crank seal I skipped the first time. (Don't skip the crank seal.) If you don't remove the pulley from the balancer, then yeah, the keyway means the crank and balancer only go back together one way and your timing marks will be in the same place when you're done as when you started. If you do remove the pulley from the balancer, those two aren't keyed to each other, so you can install the pulley the wrong way around on the balancer if you're not careful.