Slartibartfast

Good work getting it back together. Sounds like the distributor is off a tooth. Or is that what you meant by moving the splines? Make sure you're setting it with the engine warmed up. Also check that the balancer hasn't slipped, as Adamzan noted above. Hopefully clearing up the timing wakes it up! EC-23 of the '99 manual says that the knock sensor is not used to tune the engine. It's just to tell the computer if something goes wrong. I relo'd the sensor on mine to the back of the driver's side head. Haven't had any issues with it. I was glad I did it when the sensor failed and I didn't have to pull the intake to swap it out! But I imagine it would struggle to pick up the sound of knocking from the passenger's side, if something did go wrong.

That is a weird one. The 2001.5 service manual has different exploded diagrams for the two different brands of master cylinder, but there's no explanation for why there are two options. The info at the bottoms of some of the Rockauto listings show everything the same between them, with the exception of the size of the mounting holes, which are eleven thou smaller on the Tokico for some reason. (0.343" Tokico, 0.354" Nabco.) I don't see any notes on their brake booster listings for which master they go with, so I'm guessing this tiny difference (eleven thou, or 0.28mm) isn't significant to the size of the studs. I suspect that this is just two suppliers of the same part, but I don't know that, and I can't explain why the aftermarket would bother to reproduce both variants if there wasn't some functional difference between them. Looks like the body of the master should be clearly marked with the brand name, so you should be able to tell which one you've got currently. I would replace like with like, on the off chance it matters. Failing that, I'd trust Nissan's parts lookup, and roll the dice on whichever variant was cheaper that day.

My dad's '03 bucked like that too. His usual mechanic had no idea what was wrong. IIRC it didn't even throw the code, just bucked when he tried to accelerate. Someone else he took it to had seen the same failure before, and replaced the solenoid, and that cleared it up. Looks like this guy had a bad TPS somehow throw this code. Not sure if you've seen that thread already, or whether you already replaced the TPS along with the throttle body. I'd have a look at live data from the TPS, on the off chance, though I suspect the engine in that thread might've been the earlier drive-by-cable--surely drive-by-wire would be throwing more than a swirl valve code if it couldn't tell where the throttle blade was. +1 for going through the troubleshooting in the service manual!

I remember my dad's '03 doing something similar. Pulling a fuse (don't remember which one, this was over a decade ago) and putting it back brought it around temporarily, until it crapped out again. I think replacing the head unit was what got it in the end. I would try unplugging the CD changer, especially if it's dead anyway. See if that clears up the issue with the head unit. Maybe the changer was locked up, and the head unit was waiting for some signal from it? The '03 service manual should offer some system troubleshooting, and at least tell you what all is wired to the amplifier fuse, which might offer some hints.

The threaded ones, or the quarter-turn ones? I've got a warped-to-crap sunshade in my parts car with the quarter-turn knobs.

Good to hear you got it together. Did you swap the Xterra oil filter adapter as well, or work around the R50 one?

I remember reading about an issue with the Japanese starter motors in some '80s or '90s Chrysler? vans. They didn't work in Canadian winter temps, because the grease froze solid, because the engineers had not considered that anyone would attempt to drive a car when it was that cold outside. A similar thing happened with the steering transfer boxes in the early R50s. Nissan had to do a recall (#96V034000) for the grease freezing up in the steering transfer box. The recall said it got so stiff below -30 C that "some drivers would have difficulty turning the wheel."

My '93 behaved very similarly when the connector for the MAF was worn out. It ran fine most of the time, but now and then it would surge at idle, or forget how to idle entirely, especially once it warmed up (high idle when cold masked the problem). Screwing around with the MAF connector always cleared it up, for a while. I finally got tired of messing with it, and replaced the connector, and it hasn't done it since. I don't know that I've heard of an R50 doing that, but that's the first thing I'd check. (Also check for OBDII codes, on the off chance the computer has some idea of what's wrong. Mine didn't, but yours should be smarter than mine.) I have zero experience with LPG (apart from cooking hamburgers!), so I'm no help there. Though, yeah, if it only kicks in over 1300 rpm, I doubt it's related, unless something is very wrong with it.

Yeah, it seems like it would've at least tried to sputter a little at some point if it was flooding. The marks on the timing cover are approximate. The tooth count between the dimples on the sprockets is the important thing. Hopefully nothing got hurt, and the mobile mechanic figures it out!

Good work! Hopefully the bottom one plays ball. Also check Rockauto for connectors. I got a MAF sensor connector from them a while ago. If you have trouble finding a 27mm socket, try 1-1/16".

Nefarious got an R50 engine working in his WD21, with the R50 accessories, and the R50 filter adapter. Info in this thread. I'm guessing the short power steering lines had to be made custom, reservoir moved, alt and power steering pressure switch wiring modified. And it looks like he had to re-engineer the power steering pump mount, probably to make it clear the box. But it is possible! And he seemed pretty happy with the outcome. I'm curious whether a W/D22 oil filter adapter would bolt to the R50 oil pump. Might be an easy way around the problem you're having. There are signs that it may not--the oil pumps for WD22 and R50 have different part numbers, and the seals between the pump and adapter are different as well (R50 has O rings, WD22 has a gasket). But the oil filter adapter flanges on the two pumps look about the same to me, and it looks like the O rings on the R50 are grooved into the adapter, not the pump. So... maybe? Looks like the X filter adapter is still available. That should be what's on my VG33, which is on the floor and half torn apart at the moment, so if you want to compare measurements vs the R50 adapter, PM me. If you want to run the VG30 accessories, keep in mind you'll need a crank adapter and a cut-down VG30 water pump to make it work. I've heard of people running the VG30 crank and oil pump instead of an adapter, and it sounds like that works, but it also sounds like it's a downgrade of both parts. I think I've heard of 300zx guys relocating the oil filter to where that plate is (back to where the filter goes on the VG30). Not sure what they do at the front. Might be something they do when using the VG30 crank and oil pump. Have a poke around on some Z car forums, surely someone's written it up. I vaguely remember someone, might've been Nefarious, having to beat on the VG33 oil pan to make it clear the WD21 front diff. Naturally I can't find the thread now. But, yeah, something to keep an eye on as you're putting stuff back together.

That makes more sense. Too many similar names on stuff!

Maybe? Annoyingly, the manual does not explain why it's like this, just how to test and replace the components. This thread suggests that regulating the cold side helps the engine warm up quicker and makes the engine temperature more stable. I guess the idea is that the engine raises the coolant temp pretty predictably, but the radiator drops it unpredictably, depending on air speed, ambient temp, humidity, aircon, auto trans temp, heat soak, grasshoppers, whatever else. So if you want a stable engine temp, it makes sense to put the thermostat between the biggest variable in the system (the rad) and the thing you want stable (the engine). And when it's warming up, and the lower rad hose is cold, I assume that cold water coming in will help keep the tstat closed for longer, versus a hot-side tstat that only sees the hottest water in the engine. Looks like Ford's Coyote V8 and some GM LS engines use cold-side tstats, too. I did some reading on a Mustang forum, and found some of those guys talking about a difference in design between the tstats themselves (beyond just the temperature rating). Apparently some of the aftermarket tstats they were buying were actually hot-side designs, and acted weird in their cold-side application. Given Nissan's 190F tstat was intended for hot-side use, maybe that's part of why the TSB warned about it cancelling a VG's birthday. Of course that thread was about a very different engine, and unfortunately it was more pissing match than thread (maybe they'd just found out about the cars and coffee memes?), so, handful of salt there. Yeah, mine struggles down there too. It usually kicks in enough to keep the windshield clear by the time I've got the ice off the windows, but sometimes even that seems like a fight. Hopefully the 180 turns that around. Weirdly I've noticed my heater seems to warm around the stereo as much as it warms anything else. I suspect the foam sealing the dash vents together has seen better days. That's probably not helping.

Heat is your friend for that EGR tube nut. Heat, lube, beat on it, repeat. I've had some luck with candle wax for stubborn threads. Heat, melt wax into the threads, try again. Seems to stick around better than PB. I tried just brute-forcing the nut in my '95, and it took some of the threads off the valve, so, yeah, don't do that. If it's a California-emissions truck, an EGR delete will trigger the check engine light.

Hopefully the Amazon ones are good! I had to butcher the hubcaps to clear my Mile Markers. Came out nice enough, but a little nerve-wracking taking a wood router to old plastic. I'm waiting on parts for mine too, at least officially. Haven't gotten around to installing the parts I do have yet.

White smoke and one dead hole sure sounds like a head gasket issue to me. +1 on the leakdown test to tell you for sure. And +1 for doing the timing belt etc while you're in there. Cam seals, crank seal, bypass hose, belt, tensioner, pump. I skipped the crank seal the first time I did mine, and naturally it started leaking the moment I had it back together.

Maybe you got the early 27 spline hubs? The hubs and CVs switched to 28 spline between '89 and '90. Don't think I've ever seen a Ridge Line hub. Hopefully that's the last speed bump to it going back together!

Spark but no fire on carb cleaner suggests it's either massively flooded, or the timing is way off. Do you have a timing light? The ignition timing should not have changed if you haven't moved the distributor, assuming everything's as it should be behind the timing cover. I'm also assuming the last guy had it set up properly, given it ran before you opened it up. Confirm that you've got 40 teeth between cam dimples, 43 cam to crank. If you had the sprockets off to do the cam seals, confirm that you reinstalled the sprockets on the correct sides. Left and right are marked from the driver's perspective, not the mechanic's. I've never had an issue with it, though I have heard of people washing the oil off the cylinder walls by using too much. Some starting fluid has oil in it, that's probably better for extended use if you have to run it on spray. I mostly just use it to make sure a small engine's worth buying a carburetor for. I don't know if it's the ether or the stuff they add to stop people from huffing it, but starting fluid gives me a headache real quick. Not that carb cleaner is healthy, but it doesn't hit me like that. I see guys on Youtube using brake cleaner, and they seem to get away with it, but I don't want to know what's coming out the tailpipe when that stuff burns!

Towing 5k lbs with an out-of-warranty CVT seems sketchy to me. Looks like some people do it, though. Do some research on what they do to keep them alive. Fresh fluid and a cooler might help. Looks like load distributing hitches are a thing for these, probably a good idea if you're cutting it close on the tow capacity. I've never driven an R52, but I'd expect the VQ to get up and go pretty well. My dad's '03 had an earlier VQ, and it got up and went just fine. I imagine it would be screaming at you if it was in some kind of limp mode, though I would still check and see if it's got any trouble codes. I would also check that it isn't in some kind of eco mode that's nerfing the throttle response.

Looks like they've got the same lift as the VG30 cams, but a little more duration. Mr. 510 called them the best stock cams from the US market (or words to that effect) in his VG34 thread, so if a set happens to fall into your lap, I'd call that a win! This chart of stock cam specs shows the Z31 cams second only to the Euro cams, which again have the same lift, but a little more duration. Looks like the Euro cams moved the power band up just a little (traded a little low-end for a little high-end?), but nothing crazy.

Clean is a good start, but given their history, you should at least put a straightedge on them. The flatness spec (from EM-24 in the '97 manual) is 0.01mm (0.004"). Put a straightedge across the head (corner to corner, diagonal and parallel) and see if you can get a four thou feeler gauge in between anywhere. If the feeler fits, resurface or replace the head. Don't cut more than 0.02mm (0.008") off the head. If the cam doesn't spin freely in the head, because the head is warped to where the cam bearings don't line up anymore, replace the head. The difference in lobe height between the VG30 and VG33 is only around 0.3mm on the intake, 0.6mm on the exhaust. You're gonna need calipers to see that. Measure from the tip to the base circle on the far side (the full height of the egg, if that makes sense). The '95 manual says the VG30 lobes (intake and exhaust) should be 39.537 to 39.727mm. The '97 manual says the VG33 lobes should be 39.242 to 39.432 on the intake, 38.943 to 39.133 on the exhaust.

I've never worked with the 2WD parts, but I had a look at the parts diagrams on NissanPartsDeal, hoping to see the same part number between them. Instead I found six of them. 4WD shows 40202-0W094, 40202-0W091, and 40202-0W092. 2WD shows 40202-1W091, 40202-1W092, and 40202-1W094. Naturally I have no idea what's different between those six part numbers, or if it's significant enough to stop one from fitting the other. If you can't find a used one, NPD does have one of the 2WD part numbers still available. Punch in your info and see if they reckon it'll fit.

This TSB. The 190 tstat that the TSB says not to use was for unspecified earlier models. I have no idea why Motorad is listing one for VG applications now. Maybe there's a demand from people who don't know how the cooling system works. Or maybe the increase in heat across the engine is not as high as Nissan expected, as seems to be the case with yours. (Or maybe the increase the TSB is talking about is more of a worst-case-scenario, assuming hard use in hot weather.) Everything I've checked says the VG R50s ran 180 tstats. The '97 R50 FSM specs a 180. This listing shows a 180F/82C tstat as fitting '98-'04 Fronty (w/o supercharger), '00-'04 X (w/o super), '96-'01 R50, '93-'01 Quest, and '89-'94 Maxima. The TSB above says to use the 180 from a Quest or a Maxima, which makes sense, as those are the only vehicles on that list that were in production when the TSB was written in '94. How are you logging your temps?

Good work. Annoying that it doesn't know what's up, but that's OBD1 for you! You can test it with a plug, yes. I use an old spark plug for this so I don't have to take the existing plug out. I like doing it that way because it makes it harder to zap myself. When I don't have a plug handy, I stick a screwdriver where the plug would go, hold it by the plastic handle, and hold the shank maybe a quarter inch from the manifold while cranking. Otherwise you can just hold the wire (by the insulation!) so there's maybe a quarter inch spark gap between the intake and the end of the wire. This is easier with the coil wire. Speaking of zapping yourself, I haven't heard of anyone being properly injured by it, but that doesn't mean it's a good time. The ignition system should be putting out something like 28,000V. Be careful where you put your fingers, and don't hold onto a damaged wire. You could also start with the carb cleaner if you're more comfortable with that. If it kicks on spray, then you know it has spark, and you can skip messing with the plug wires.

I'm 90% sure I put a 170 in my VG30 when I had it apart. I have noticed it struggling to hit temp when it's real cold out, but I think I remember it doing better when the tstat was new, so it might just be aftermarket junk that's on its way out out after 30k miles. I bought a 180 tstat from Nissan for the VG33 to see what that does. It'll probably be summer by the time I get that engine in the truck, so I'll know pretty quick if 180 was a mistake.