Slartibartfast

A vacuum leak generally causes a lean condition, not a rich one. Rich condition could be a leaky injector, bad coolant temp sensor, or possibly a borked oxygen sensor, though I wouldn't expect that to kick in at idle (idle's usually open-loop, meaning the computer isn't watching the oxygen sensor in the first place). Check your spark plugs. If one of them is wet, and the others aren't, that points to an injector leak. If they all look the same, I'd check the connector on the temp sensor. The computer adds more fuel when the engine is cold, so if the sensor is bad or the connector is corroded, it'll think the engine's cold as hell and inject way too much fuel for the temp the engine is actually at. There are two temp sensors on the nipple the upper rad hose goes onto. The one-wire goes to the cluster, the two-wire goes to the computer. There's a test mode in the ECU to monitor your oxygen sensor (via a blinking light on the back of the ECU), but that only tells you if the sensor is cycling, not why it isn't. EF&EC section of the service manual is your friend. You can get the '90 service manual free from cardiagn.com, or the '94/'95 (also free) from Nicoclub. The '90 covers my '93 more closely than the '94 does. Also check the vac line to the fuel pressure regulator (back behind the plenum, should be able to reach it on the passenger's side). Make sure it's connected (not that it would cause this issue if it wasn't) and that there's no fuel in the vacuum line, which would indicate a failed diaphragm. I haven't heard of that happening on one of these, but it's an easy thing to rule out.

If you're replacing just the switch, it's surprisingly easy! One Phillips screw IIRC. Be careful taking the clamshell off, though, they're a bit fragile.

I'm not sure how the quick-connects work, but if they're like an air chuck, they could be blocking off the port because the connector's not fully seated. Like I said, I don't know the R51 from a hole in the ground. You can get the service manual for it here. Might be something useful in the fuel system section, or at least a diagram you can check your work against. If not, you might find some troubleshooting info in another section that shows how they want you to check fuel pressure, or suggests some other things to check. Good luck!

I took my starter apart when it started acting up and found that the brush holder assembly was all jacked up. I couldn't find the right parts to rebuild it, so I replaced it with a new Bosch. They're not fun to get to and I didn't want to do it twice.

Does sound like a windshield seal issue. Also check your sunroof drains, if it's got a sunroof. Should be one drain on either side, going down to the rocker panels. The cowl air intake is on the opposite side, like Mr. Reverse said, and it's also got a raised lip around it to keep water out. Wouldn't be a bad idea to check behind the blower motor resistors, though, they tend to accumulate sticks and leaves in there. And yeah, the A pillar trims just pop off. Hopefully the leak reveals itself once it's open.

Those are classic symptoms of blown trailing arm bushings. Hopefully it's not that again, but, yeah, that's what I'd check first.

I'm not familiar with the R51, but it sounds like a tank pressure issue, like the evap vent system isn't working properly. Check that you put the evap hoses back where they go when you put the new pump assembly in, and that nothing got pinched. (I'm assuming your fuelling issue and your starting issue both began after your pump replacement?) If it is an evap fault, I'd expect it to throw a code for that as well. When it won't start, if you remove the fuel cap, does it whoosh and then start up like nothing happened, or does the issue persist? Also check the fuel filler neck, make sure it's not kinked or wonky, that could be causing the pump click-off issue. If everything checks out at the tank, check your fuel pressure at the rail. Hopefully Nissan gave you a proper test point on yours.

I'm hoping to get my aircon going for this summer, I'll have to take a look at the lines and the foam under the condenser. I think there was foam under it originally but I'll be surprised if it's still there and doing something. MCM used a pump-up bug sprayer to spray an intercooler, might be good enough for a test run before committing to a proper setup.

They put gear oil in it? Holy crap. No surprise it didn't like that! Good thinking with another drain/fill to get the last of it. I'm left wondering why it would've disengaged the rear end, though. The hydraulics only control the clutches for the front AFAIK. Maybe it was trying for low range and got stuck in neutral? I don't know how that box reacts when it gets confused. Seems unlikely that the trans and transfer would choose the same moment to have an issue. In any case, hopefully the new fluids resolve the issue.

AT-280 in the '01 manual shows separate breathers for the trans and transfer, running up to a sort of breather manifold near the bellhousing. Odd that they didn't just tee them and run them up to the engine bay, but I guess the way they did it prevents one box from dumping fluid into the other. Looks like your transmission breather outlet is on the driver's side, towards the top. Not sure how easy that'll be to see with the driveshaft and all in place. Mirror on a stick may be your friend. If it is blown off, it wouldn't be a bad idea to blow out the breather line, make sure it doesn't have debris or a mud dauber or something blocking it off. It does seem odd for it to boil over under those conditions unless something else is wrong. I would inspect the cooler lines to see if they're pinched or kinked somewhere, and check that the cooler isn't clogged.

I'm a little confused by your first sentence. Did you engage 4HI, then find that you had no drive whatsoever to any wheel (engine revs, nothing happens), then smoke--or did you engage 4HI, the rears spun but the fronts didn't, and then smoke? If it's the former, I suspect your transmission overheated and boiled fluid out of its vent tube. Maybe that hose was damaged, wasn't on its barb right, or just blew off. The boiling fluid prevented the pump from making line pressure, so the clutches failed to engage, and you had no drive until the transmission cooled and the fluid settled down. How hot was it where you were, and how hard were you working it? Are you running an external transmission cooler? If it's the latter, that would suggest a transfer case issue. Park it on a surface you don't care about (gravel, neighbor's driveway) and try to put it in 4HI again. If you're right about a seal being bad and releasing hydraulic pressure meant for the clutches, and the transfer case hasn't already pumped itself dry (check the level first), it should start spraying again when the pump comes on. I wouldn't expect the case seal to be holding back line pressure, but I don't know the ATX14A very well. If it doesn't spray, check that it's actually in 4HI. Either way, the first thing I'd check is the fluid level and condition in your trans and transfer. Then I'd have a look at the breather to the transmission, see if it's still attached. The breathers shouldn't need hose clamps, but that doesn't mean it's a bad idea. I've heard of ATF puking onto exhaust components and starting fires.

Interesting. My understanding of that box is that the motor runs to spin a pump, which applies pressure to the clutches that keep 4x engaged. Maybe the shaft bushings in the motor are going out? I'd be curious to put 12v to it and see what it sounds like, and whether a little oil on the bushings quiets it down.

I found a little piece of brass in the front diff of our snowplow when I had it apart (after blowing up the spider gears, oops), and I'm still not sure where it came from. Hopefully bearing replacement #2 kills your noise. I've ordered parts for both sides of mine, figuring that if one side has worn out, the other can't be far behind. I hadn't heard of the chassis ear system, that looks like a nice piece of kit for this kind of thing.

There's a plug-and-play converter box for the D21 pickups, but the WD21 needs the converter wired in. Not too complicated, though. I had what I suspect was a cheaper box wired into mine and it had so much voltage drop across it that you couldn't see the flashers if the running lights were on. I assume the higher-end converters have better transistors in them. I made my own converter from cheap relays instead. It's noisy and took some tinkering to get it working right, but the parts were cheap and it solved the problem. It's also got its own fuse, so if the trailer shorts out, it can't take anything else with it.

Nice! Must be a relief. What I've done to track down steering slop is to have someone hold the steering shaft with vise grips while I try to wiggle the wheel, then work downstream until the slop shows itself. A friend and I used this method to diagnose his S10 with a worn-out joint in the tilt column (which looks like it'll be a right pain to replace). If it's tight up to the rack, check the rack bushings. Also check the rack mounts, common R50 issue from what I've read. Went out on my dad's Tundra too.

I don't think there are a lot of R51 guys around here at the moment. I guess it would depend on how much body lift the R51s need for popular tire fitments. Seems like you could make the 1.5" kit, but make it stackable, so a customer could order one kit and be at the limit of lift without further mods, or two and jack it way up if that's what they're after. I assume either option would require different bolts, though, so maybe that wouldn't work as well as I'm thinking.

Looks like there's a small gap between the bezel and the head unit, and something reflective behind. If you can't scoot the bezel over, you could just paint the reflective part of the head unit so it doesn't show as much.

If it had one leaky injector, it would have one wet plug. Six wet plugs says it's getting fuel but not firing. Starting and running eventually says it has spark, though it wouldn't hurt to verify that it has spark even when it refuses to start. I like Colinnwn's idea of holding the throttle a little open to rule out an idle control issue. I would also pull the vac line off the fuel pressure regulator to see if it's leaking gas into the manifold. Not likely the problem, but easy enough to check. I'd also be tempted to double-check the tooth counts on the timing belt in case the last guy set it the same as it was when he took it apart rather than looking up the actual specs. Long shot, but something to check if you run out of other things. The ignition timing is probably not set right (tough to set timing on an engine that doesn't run), but I don't think that could cause the issue you're having. Keep an eye on the oil and change it once you've got this figured out. In an engine that's flooding/not firing, the excess gas in the cylinders runs past the rings and dilutes the oil. I've got a small engine in my shop right now that flooded repeatedly due to a carb leak and what I drained out of the crankcase looked more like wood stain than oil.

Bezel looks good!

I used a semi-gloss on mine. Turned out looking pretty good IMO and it's held up reasonably well. I think it was just Rustoleum in a can. Gloss is tougher to work with and shows every fault, and I figured flat would be harder to clean and end up going chalky.

Carpets came out nice. I need to pull the carpet back out of mine and run the rug machine over it one of these days.

Aftermarket gears are listed as fitting both the R50 and the D22, suggesting that the pinion length should be the same. The pictures look like the ABS sensor on the D22 3rd is occupying what's wasted space on the R50 3rd, but, yeah, measure if you're not sure. If it's the same length, and the same bolt pattern on the flange, you should be able to just chuck the whole 3rd in there, though I would be tempted to make some kind of blockoff plate to cover the broken-off sensor. The front diff will need to be from an R50, though, the R50 front end was unique unfortunately.

Slap a second heater core in there and make a warming oven! Hot burritos anywhere.

PM sent! RCWD21, if there's something you need from the '87 manual, let me know, I have a hard copy because it was cheap on fleabay and I'm a hoarder apparently. I'd expect it to be largely the same as the '89, except that the ECU trouble codes are slightly different.

I tried braided lines on mine. Noticed zero difference. Went back to rubber when I realized that the lines I had weren't coated, and so were vulnerable to abrasion as road dust got between the stainless steel and the hose inside.