Slartibartfast

Alright, one stupid idea first. Is your air cleaner on? I've read about TBIs getting upset when they're run without the full box. I'm assuming your Replaced Everything list includes vac lines, temp sensor, and oxygen sensor, and that the wiring is all good, and I'm also assuming you've checked for ECU codes. Given that the issue changes when you shut it off or screw with the electrics, the fuel puddling sounds like a symptom of the computer throwing too much fuel rather than a leaky injector. Given that the MAF is something you haven't replaced, and unplugging it seems to improve the idle issue, I'd try swapping in a known good MAF. I've actually got a TBI MAF on my shelf but because the donor was long dead, I have no idea if that MAF is any good. I'll bet the idle is caused by the fuel issue, either directly or because the computer is trying to compensate for something. I'd focus on the fuel issue first and see if the fix for that clears up the idle too.

Looks like a clean rig. Bumper rot doesn't look too bad. I assume you checked the strut towers? The death wobble is pretty well documented and not the end of the world to fix. If you're concerned about it, you could replace the bushings as preventative maintenance. I think it also depends a lot on how the truck's been used. A rig that's been wheeled heavily will have more wear on those bushings than a rig that only sees 4x4 when it snows. My '93 has higher mileage and the original (so far as I know) bushings and rides fine. My concern would be with the timing belt. PO says he's had it for 125k so he should've replaced it at least once in that time frame. If not, it's due (and might help you talk the price down).

Still no idea if factory or not. Guessing yes by the diversity switch? But if you pull out that black plug that you can't see in the picture, and test from that yellow wire to ground (a clean spot on the metal frame under the dash should do), you should find 12v. Also check that fuse on the back of the radio on the off chance. It probably wouldn't work at all if that one was blown but it's easy enough to check. The only other thing I'm seeing is that the white-wrapped harness in the dash looks like something jammed into it pretty hard. I don't think that one is audio but you should take a look and make sure you don't see bare copper.

You guys are overthinking the holy hell outta this one. Those vents are there for the same reason Mustangs have fake brake scoops, H3 Hummers have fake hood louvers, and my friend's FWD commuter car came with a spoiler. Somebody on the design team thought it looked cool. Seriously, you think the WD21 was designed in a wind tunnel?

Heh. My sunroof seal on my '93 failed the other day while I was driving and started flapping against the roof. That made some noise! I could see it waving around like a waving arm tube man in the truck's shadow so I didn't worry about it, just pulled it off when I got where I was going. I honestly haven't noticed that much change in wind noise with the seal gone. I've got a sunshade up, though, maybe that's absorbing some of the noise or something. I've heard the new seals are a pain to install--surely there's a trick to it though. You might take a look at the hold-down buckle whatsit for the sunroof and make sure it's adjusted right to where air's not getting in between the glass and the inner seal.

Huh, a non-93 with auto climate control... they do exist! I can't see a whole lot of the wiring for the stereo itself. Is it aftermarket? It looks aftermarket but it's been a long time since I saw the back of a stock one. Can you get a picture of the wires coming out of the plug on the back of the radio, particularly the red and yellow ones?

Gave the speakers a good test

That's not good. I'd start disassembling where you saw the spark and where you worked to swap out the regulator and see if you can find anything obvious. Loose wires, scorch marks. Maybe something fell off the gas gauge? I would expect to find a bad fuse somewhere, but if you don't find the short first, you'll just blow the next fuse too. Also check your fuse links, the short lengths of wire hanging off the + battery clamp. They're basically just big fuses, though they take a lot more to blow; I'd be surprised if a short in the cluster managed to roast a fuse link without blowing something else out first. Not sure what role the HVAC lights play in this. I'm pretty sure they're on the same circuit as the dash lights, if that helps any. If you can't figure it out, probably best to button it back up and take it somewhere. I know mechanics hate it when they get something half torn apart with no indication where stuff went.

The radio in my dad's '03 did this. Wouldn't turn off unless we pulled the fuse. We never did figure it out, just swapped it out for one from the wrecking yard, and that fixed it. I tore down the old one and couldn't find anything wrong with it. No idea on an R51 though, that's new enough that I'd start wondering about body control modules and whatnot.

I'm no HVAC tech but yeah, that's not a good sound for a compressor to make. It can be done at home, if you're up for a challenge. I helped a friend replace the whole system on his Blazer. We weren't sure what exactly was wrong, so he bought pretty much every part and we just swapped out the lot. It wasn't too hard of a job but we had to make sure to get the oil level right, and vacuum the system down before filling, and of course fight past all the junk Chevy had packed in around the stuff we needed to get to. We found that the compressor had died a crunchy death and spewed shrapnel into the system. The bits accumulated in some kind of screen before the evaporator core. Because we replaced pretty much everything, there was nothing left to flush, and because the old system didn't hold pressure, we didn't have to deal with the old refrigerant either. He bought a manifold set for recharging but forgot the adapter, so we just charged it with one of those cheap recharge kits you can get at auto parts places. A shop would probably evacuate and fill for you if you didn't want to do that part, and I'm sure somebody's worked out how to flush components at home. I guess it comes down to whether you'd rather screw around with it yourself or cut a check.

I don't know the TBI throttle body too well but every TB I've seen closes more or less completely unless it's held open by an adjuster screw or a fast idle cam or something.

The headlight switch has a contact for markers (tail lights and the front corner lights) that also does dash lights. It's the center one in the switch IIRC. Not too hard to take apart and clean, or you could just replace it. I had my dash lights refuse to come on a while back but the outer lights came on just fine. It ended up being the dimmer being full of gunk.

Anything you think you can sell or might need for yours. I'd rather save lots of parts I don't use than realize I chucked the one part I need. Relays, fuses, light bulbs, fasteners, I'm sure there's a lot of shared parts that could save you a trip to the auto parts store later on. The interior might be worth a quick look too, on the off chance there's something good hidden somewhere. (Didn't Xterras have some kind of first aid kit in the rear hatch?) I'm not sure what good the rear axle will do you though. The suspension's different from the Pathy so it won't swap directly, and the spline count is different so the 3rd won't swap in either. Unless you have someone who wants to buy it, or it's got the 4.9 gears, I wouldn't bother with it.

Unless the TBI dizzy is very different from the MPFI, it can be adjusted, you just loosen the hold-down bolt and turn the whole dizzy to change timing. I can't imagine bad timing making it rev high, though, much less that high. I think you're thinking of a diesel with the leaky injector, more fuel won't make a gasser run any faster unless there's more air to burn it. +1 on checking for codes. The first thing I would check, though, is the throttle body. Just make sure the throttle is actually closing. The throttle cable could've frayed and bound up in its sheath, or something could've fallen in and jammed the throttle open (saw a guy on Youtube pull part of his airbox out of his Subaru's throttle body). Could be the idle air control but I'd be amazed if it could pass enough air to rev the motor that high.

Does sound like possible EGR to me. First thing I'd check is the vac lines. Cleaning the intake's not a bad idea, the best power boost I ever got from my '95 was when I cleaned the muck out of the throttle body.

Finally put my stereo in. Nice to have the dash mostly back together.

^ That's where I'd start! Getting to the radio itself isn't too hard. IIRC (been a while) you pull the ashtray out, remove a couple of screws from the center bezel, pull the bezel (helps to pull the shifter out of park), then the radio and its fasteners should be right in front of you. If it's aftermarket, and the fuses in the box check out, you may be right about the constant positive lead being disconnected. Hopefully the PO didn't leave you a suitcase connector fustercluck in there.

IIRC it's 40T between the cam sprocket dimples and 43T from the cam sprocket dimple to the crank sprocket dimple. It's all in the write-ups and in the factory service manual. There should be assembly lube in the motor but the crank may still be difficult to turn. I just threaded the crank bolt back in and used that with a breaker bar to turn it to where I needed it to be.

Thick oil and a light foot and hopefully it'll hold until your rebuild's ready.

I wish you the best of luck welding conduit with flux core! I used flux core with my 140 when I got it and it was fine for welding thick stuff together but it was a real pain on the thin steel barbeque stand I made my welding cart out of. I ended up doing a lot of little welds and a whole lot of wire brushing between each weld to clean off enough of the soot from the last weld for the wire to make electrical contact again. (It didn't help that I hadn't quite figured out the whole wire feed rate setup yet.) When the sample spool of flux core ran out, I got a gas bottle, and I haven't welded with flux since. Also make sure you've got good ventilation. Maybe even a respirator. Besides the obvious fumes from any welding process, and the additional fumes from the flux, the conduit I've seen is galvanized. I've been kicking around ideas for a roof rack myself, so I'll be interested to see what you come up with!

Huh. That's unhelpful. I wonder if your pump is aftermarket. If you can find where that harness plugs in (likely by braille), can you pull it out enough to see the wire colors for the harness it plugs into? That part of the harness might be coded differently. Or maybe Nissan just ran out of blue striped white wire and figured purple was close enough. I did find a couple threads with close up pics of where the wires go. This one shows a white wire w/blue stripe. This one looks like it might have your white with purple though.

The diagrams do take a little getting used to but once you figure them out, they're really helpful. The letters tell you what color the wires are. Pretty intuitive except that L means blue. So looking at the diagram, you have the thing with the M in it (the pump Motor) with a black wire ( and a white wire with a blue stripe (W/L) coming out of it. Black is ground (as it usually is) and white with a blue stripe is your + line. There are two motors shown but I think that's just covering the difference in wiring between the D21 and WD21.

Factory service manual. Download here: Index of /FSM/Pathfinder I don't know when the computer needing to relearn stuff started to be a thing, but running it with the idle air unplugged and then plugging it back in again may well have confused it. I would unhook the battery and leave it overnight to make the computer forget whatever it thinks it knows, but I remember my dad's '03 had some kind of Konami code that would reset it properly (some combination of turning the key on and off and playing with the pedals). Should be in the service manual. The EF&EC section is where I'd start.

Gotta love the easy fixes!

I have no plans to take one of these apart but I'm following this thread anyway! Thanks for documenting the teardown.