Slartibartfast

Reminds me of doing the starter on mine. Hopefully you don't have to do it again any time soon!

I'm no help on backspacing, but I would want more than bare minimum clearance on the brakes. My dad had a set of winter rims/tires for his Tundra which sat pretty close to the calipers. Most of the time, they were fine, but now and then they'd make a racket like the world was ending. Near as I could work out, this was due to a rock or something getting caught in between the caliper and the rim. It never tore off a caliper or punched a hole in a rim, but the noise scared us pretty bad once or twice. Also keep in mind that the calipers may stick out more with new pads on them, so what barely clears now may not clear after your next brake job.

Nistune, maybe? They don't officially support Pathfinders, but My1Path got one working on his WD21 ECU, probably because the computer was similar enough to one of the models that they do support. There may be a similar close-enough compatibility to get one running on the R50. I don't know if anyone's done it yet.

The service manuals confirm what you've found with the wiring. The '87 manual shows the white wire from the tach going through a 2.2k ohm resistor to the + side of the coil. The '90 manual shows the white wire going to the computer, then a white/green wire going from the computer, through the same 2.2k resistor, again to the + side of the coil. So, yeah, sounds like the TBI system runs the tach right off the coil, while the MPFI runs it off a signal generated (or at least modified in some way) by the computer. If you're married to/stuck with the '87 cluster, you could cut the white wire from the computer to the tach, tape up the end going to the computer, and splice the end going to the tach into the white/green wire. That would give the TBI tach the signal it expects. Or, if you'd rather modify the cluster than hack up the harness, you may be able to swap just the tach from the MPFI cluster into the TBI cluster. The drawings of the clusters in the two manuals are not quite identical, but they are very close. I would not be surprised if the tachs interchanged mechanically. I would however be a little nervous about swapping the plastic needle from one to the other to make the tach look at home (I'm assuming the '87 is orange and the '91 is white). If the tach itself is the same between the two clusters, but has different control circuitry, and that circuitry is easily separated from the tach, maybe you could just swap that circuitry from one tach to the other and leave the rest alone. If that pans out, you could basically convert the TBI tach to an MPFI tach, and get the job done without hacking up the harness or prying on a 36-year-old plastic tach needle. Or, yeah, if you don't mind the look of the '91 cluster, save yourself some screwing around and just huck that in there.

I'm pretty happy with the LSD in mine, but I'm not climbing any trail class ladders with it. An LSD is just an open diff with clutches jammed in behind the spider gears to make them harder to turn, so if you're looking to build a rock crawler that'll spend half the trip with a wheel in the air, the LSD will probably disappoint you. Short of that, and on a budget, LSD is good, or at least a hell of a lot better than an open diff. The R50 LSDs were pretty nerfed, possibly for stability reasons (the WD21 LSD does make it pretty easy to get the rear end to step out in the snow). Hawairish did a great writeup on how to repack them to make them useful. Sounds like there's a limit to how tight you can go before you start breaking stuff. If I was going to throw money at my diffs, I'd leave the rear LSD alone and put a ratcheting or air locker up front. But, yeah, some of us is poor, and my truck needs a lot of things more than it needs a front locker I might use once every couple of years. I don't think I've had it properly stuck since I put a decent set of tires on it.

I don't know the throttle body injection, but, yeah, could be a loose connection, a leaky injector, something along those lines. Best I can offer is the '89 service manual. Should be the same as '88 AFAIK. '87 has a different list of trouble codes, which is just different enough to trip you up, so if yours is an early '88, make sure you know which version you're working with. If it codes 44 for "no malfunction indicated," you need the '87 codes; if it codes 55, it's got the codes described in the manual linked above. I have a paper manual for '87 and can send you the earlier code list if you end up needing it. If the manual doesn't get you anywhere, I would look for any obvious loose connections or damaged wiring, clean the throttle body if it's getting gross inside, clean the MAF (very carefully) if it needs it, and maybe throw a can of berryman's in the tank on the off chance it does something.

Good to hear you got to the bottom of it! Bulb sockets can be a pain when you can't see what you're doing. Easy to get something cockeyed. And yeah, if you swap in the Hardbody buckets/grille/corner lights, you can run the conversion housings with H4 halogen bulbs. I'm not crazy about the look, but I'm told the light output is better than what you've got. A while back I saw conversion housings (pretty sure they were projectors) in the Pathy "sad eye" shape, but I haven't seen them for sale recently. They had LED halos and crap, don't know if they were good or not. So many other vehicles used the same standard rectangle sealed-beams as the Hardbody that there's no lack of options there. I relayed my stock lights, and the output/pattern suits me alright, except that one of my headlight housings is aftermarket and projects a weird little puddle right in front of the truck. Not sure why. Can't see it while I'm driving so I haven't looked into it yet. I've got most of the HB conversion kit off my parts car, but again, I'm not crazy about the look, so I may or may not get around to trying that.

I would expect the inner sheet metal to be the same across the board, but I don't know for certain. Early ones might have different mounting holes.

Good work finding it in the end! Hopefully it wasn't the fuse links that got hacked up.

Assuming your truck was originally delivered to Canada, it should have a daytime running light module. That might be your issue. My truck doesn't have it, so I've only seen it in the service manual, and I'm not entirely sure it could kill the high beams on both sides. I'm not sure what else it could be, though. I would expect a bad ground to kill the high and low beams at the same time. The switch is a common fault on these (stupid non-relayed headlight wiring), but it has separate contacts for each filament, so it's unlikely to lose both high beams at once. You can get the '90 service manual for free from cardiagn.com, or the '94/'95 free from Nicoclub. Either way, you want the EL section, page 39 in the '90 (probably the same in the later one). No troubleshooting, but there is a schematic and wire colors and whatnot for the Canadian DRL system.

4WD Pathy/pickup outer fenders are the same AFAIK. 2WD pickup fenders aren't flared out as far. I remember finding out the hard way that the mounting points for the rear plastic fender flares changed at some point (probably mid '92), not sure if they did the same for the fronts. Inners, do you mean the plastic liner or the sheet metal behind it?

When I pulled the engine out of my donor, I knotted old seatbelts around the engine mounts and ran those up to the load leveler. Found out later both mounts were broken, not sure if I did that or if they were like that before I started. Luckily they held. I was pulling the engine and trans together, so having both straps tied pretty low on the engine wasn't an issue. If you're pulling just the engine, you might want to find somewhere to bolt a plate. The back of the heads have a few threaded holes IIRC.

It'll have to be someone who knows more about the R51 than I do! I don't know much about them to begin with, and that one's a diesel. Looks like a good starting point for what he wants to do with it, though. Bet it's claustrophobic in there with that tint.

Sounds like the coil is getting power, but the computer doesn't know that the engine is spinning. The first thing I would do is confirm that the rotor in the distributor is spinning. That's where the one and only position sensor is in this engine, so if that's not spinning, you won't have spark. That would also mean a failed timing belt, so hopefully it's not that. Are the injectors spraying fuel? If they are, the computer knows the engine is spinning, and the problem is in the ignition circuit. If they aren't, that's another sign the computer doesn't know what's going on. Double-check your wiring and make sure nothing got pinched or smashed during the engine swap, and all the connectors on the passenger's side valve cover are seated properly. You can download the '95 manual here.

Yes. Power locking is its own system. The alarm/keyless taps into that system, but with it gone, the power locks respond to the key the same as they ever did.

Yep, cheapest will likely be fixing the existing VG30, unless it's well and truly buggered. Second cheapest would be replacing it with a VG30 that isn't blown up. Third, and the only cheap upgrade, is the VG33 swap. If you're looking for a direct-fit, exact same engine, you'll find it in a mid '93-'95 WD21 Pathfinder or D21 Hardbody truck. If yours is 4WD, the donor should be too. There are a lot of four-cylinder D21s out there, obviously that won't work. '90-early '93 have the same engine, but with square-tooth timing belt sprockets. '87-'89 have different fuel injection. If your truck has California emissions, you may need to salvage the EGR valve off the old engine, as I don't think the federal version ever got the valve with the temperature sensor that the California-spec computer expects to see. Unless you're sure the replacement engine had its timing belt recently, plan on doing that before it goes in. It's doable in the car, but I'll bet it's easier on a hoist or engine stand. If the timing belt slips, valves and pistons have a party and you're back where you started.

Nissan has their own recall lookup, might give that a go.

If the alarm is turned on, and you turn the key twice to lock all the doors, yes, it'll activate the alarm. I only know because that's all that could've turned it on the one time mine went off. No idea if locking the doors by hand or locking one and then closing it would arm it. Manually locking the front doors locks them all, so, probably. But if the switch is off, it's off.

AFAIK the alarm doesn't arm when the doors are unlocked, so, yeah, that should be fine. When mine still had an alarm, I just left the alarm switch on the console turned off. I only had the alarm trigger once, and that was when I'd accidentally bumped the switch and turned it back on. If the driver's door switch doesn't work, that's where I'd start. They get dirty and corroded inside. They're supposed to be electrically open (door closed) or closed (door open), but if it's got the green crusties inside, it might be leaking enough current to make the alarm brain think the door is open, but not enough to illuminate the dome light. Remove the driver's door switch and see if that fixes the alarm. IIRC the door switch grounds through the mounting screw, so you could remove the screw, leave the door open, and see if it'll lock normally with the fob. If it does, the switch is bad. You might be able to get it open and clean its contacts. If not, replace it. The rear hatch latch switch is an odd design. It's built into the latch assembly. The usual fix when it starts to act up (dome light stays on, or flickers when you go over bumps) is shimming the striker. If yours is working as expected, leave it alone.

Sounds like it thinks a door is open. Might be a door switch, might be the hood pin, might be the light switch in the rear hatch latch that tends to go bad on these. The later alarms had the starter kill relay up in the dash (earlier ones had it inside the alarm brain), so that's probably the click you're hearing. NTB93-036 is the only service info that I'm aware of for the keyless entry/alarm system. If you don't mind losing the keyless entry, the alarm is pretty easy to get rid of. Most if its harness is plugged in between the factory wiring--so you unplug the factory wiring on either side, get the alarm harness out from in between, and plug the factory wiring back into itself like the alarm was never there. The alarm brain is the square box under the driver's seat (not the rounded one, that's for the ABS). You will need to remove some trim to get it all out. IIRC it plugs in between the ignition switch and the main harness, and between the driver's door harness and the main harness, and also intercepts the horn, and then is Scotchlock'd to the dome light circuit (near the fuel door release switch) and the parking lights (inside the steering column clamshell). It's also got wires going into the engine bay for the hood switch and the siren, but those are bundled with the fog light wiring, so don't start cutting until you know which wires are which. If you're not sure if a harness is alarm or factory, look closely at the insulation. The alarm harness has the purpose of each wire printed onto it, and the factory harness does not. Pulling the alarm wiring out of mine got rid of an intermittent weak start that I'd been fighting with for a while. I didn't have the keyfob for it anyway, so nothing of value was lost.

I'd be very surprised if the WD21 and R50 floor pans were similar enough for that to work.

Hopefully the obvious surface damage is all there is, then. Most of that stuff is available, and I'll bet some of it could be brought back around with some epoxy and some strategic hammertime, depending on your skills and standards. The hood's a bummer, though. That was in way nicer shape than mine.

Yeah, I was surprised at how easy that switch was to replace in my '93. Good to hear it's similar in the R50. Hopefully the fix holds.

Some modern trash can be stolen via scan tool. These are too old for that. Unfortunately it looks like yours is also too old to have the factory immobilizer (looks like that started in '99?)--though that's not all bad, as you don't have to pay through the nose to get a new key cut. A kill switch for the starter, fuel pump, or both wouldn't be too hard to rig up. Mighty Car Mods and Chrisfix both have youtube videos on installing kill switches, and you can get the wiring diagrams from Nicoclub to see what runs where. Just make sure you do it cleanly, with minimal harness hacking, in a way that's not going to give you problems later on. Things designed to make the truck not start have a way of making the truck not start when you'd rather it did, especially if they're poorly done. I removed the stock alarm from my '93 because it was interfering with the starter circuit intermittently--and that was port-installed, not even aftermarket crap. Make a note of what you did (which wires, what color, cut where) in case you (or someone else!) need to troubleshoot an electrical fault later on. Sounds like the switch in your friend's D21 is breaking multiple circuits. Probably just a double-throw switch, with one side cutting the starter circuit and the other side cutting power to the dash. I too have removed the fuel pump fuse when parking somewhere I didn't trust. I've never had someone try to steal it, so I don't know how effective that would've been. Depends on the tweaker, I guess.

What codes is it throwing?