Mr_Reverse

It is a possibility, I have had it happen to mine. More likely you have a failing ignition switch. The starter contact in the switch starts getting iffy after a decade or 2. Easiest way to tell is to connect a voltmeter to the solenoid wire and a good ground. Have someone turn the ignition to start and see if you have battery voltage at the starter solenoid. If so and the starter is not cranking well, then the starter needs replacing. If like in most cases it drops to 9v or less, then the switch is the most likely problem. An easy place to get at the wiring for the testing is a grey oval connector with 2 wires. A black with purple stripe that is large and a yellow with blue stripe. It is next to the battery. The black/purple wire is for the starter. If you use a jumper from the positive post to the black/purple wire, the starter should crank normally. This where I installed a relay years ago when my starting issues got bad. It allowed the failing switch to keep working.

There is the camshaft bore cover on the back end of the head that is known for having it's screws work loose and letting oil leak.

Ok, sorry it took so long to get back. With the ignition in the on position, you should have battery voltage on both black white stripe wires at the fuel pump relay. If so, power supply is good. If you put a jumper wire from positive post of the battery to the white blue stripe wire at the relay socket, you should have battery voltage at the fuel pump on the white blue stripe wire. If so, the wire is good between relay and pump. Should have less than 2 ohms when measuring between black wire at pump and good ground. If so, ground is ok. The ECU controls the ground for the fuel pump relay. If the relay clicks when the ignition is turned on, the relay drive circuit is ok. With the red blue stripe wire at the fuel pump is grounded with the ignition on, the relay should click on and you should have battery voltage at the fuel pump on the white wire with blue stripe. As for testing the fuses, pretty simple. Using a test light or volt meter, connect the negative to a good ground and of you look at the top of the fuse, you will see a small hole on each end. Poke the tip of the positive probe into the hole on one end and then the other. Both should give the same battery voltage if the circuit is on. If one side is "hot" and the other is not, then you have a bad fuse.

Ok, so the pump runs when you run a wire from the + terminal to the white/blue wire terminal for the relay? If so, the wiring to the pump and the ground is ok. The problem is either the relay is not operating, the contacts in the relay have failed, or the positive wire to the relay has an open. Do you have power on both sides of the fuel pump fuse? Does the fuel pump relay click when the ignition is turned on and off? I will try to remember to look up the diagram tomorrow at work to refresh my memory of the system.

One thing to help is to look for the plugs for the shocks. It is a grey oval with 3 wires. There are 4 of them, one for each damper. They are hanging near where the top of each damper is bolted to the frame. Find the diagram to make sure, but I believe the center wire was the common and the outer ones were for the switch. A simple noid light or voltmeter should indicate if it is functioning. With key on, should have power to the plug, and switch position should determine which wires are energized.

It was a few years ago for my friend, and I left the dealership a little over a year ago, but I do remember doing a rust inspection on an R50 a couple months before I left, and I did a lot of steering intermediate shaft replacements on first gen Xterras and Frontiers under rust recalls.

My Pathfinder is a unique collection of parts that mostly works for me. That said, here is my input. My 93 when I bought it in 99 had 128k miles on it and I assume the factory installed switchable shocks were the original units. I never noticed a change in mine when switched between sport and touring. I did the tests and was able to hear all 4 click when the switch was operated, just felt the same to me. I did a 3" suspension lift using the kit with 30% stiffer torsion bars and 3" coils from AC about 20 years ago. It came with a set of the Rancho 5000 shocks. I hated them, just didn't work well for me. I eventually changed the rear lift coils out with a pair of front coils made for a late 70's early 80's Ford F150. I trimmed the pigtails off to fit my mounts. They gave me lift I was looking for, but a very harsh ride unless I had 700+ lbs in the back or a trailer hooked up with good tongue weight. Also had a tendency for the right spring to fall out when flexed out. I had found the rear shocks were a little too short for the lift and so got a pair of ProComp ES3000's for the rear. These shocks did ride better than the Ranchos for me. Then I got tired of the issues the Ford springs had, and went back to the first lift coils with a spacer to give me the rear lift I was after. That setup just was not working for me, so got a pair of 4" lift coils for the front of a 90's Grand Cherokee. I trimmed a coil off with the pigtails to fit my stock mounts. They gave me the 5" lift I was after and I found the ride to be a bit firm, but not bad. I tend to carry a couple hundred pounds of "stuff" in my truck so worked for me. Had one shock finally blow it's seals and die. I picked up a pair of Bilsteins that came off a new 17 Titan Pro4x for the great price of free (the parts department at the dealership I was working at was tired of the pile of them sitting there as take-offs from the Titans that had lifts installed and was throwing them out). I had to do some grinding and drilling on the bushing eyes to fit the mounting studs on my truck, but they fit well and work great for me. Up front, I finally broke the right front shock a little while back. Found a pair of ProComps and have been satisfied with them. I started with a 3" suspension lift, and I have maxed the front out. It has been a miserable experience for me over the years. I have gone through a LOT of tierods, idler arms, ball joints, center links, bushings, CV boots/axles and such. I also installed a 3" bodylift about a year after the suspension lift. If I was to do it again, I would leave the suspension near stock, probably just turn it up about 1 1/2" and do the 3" bodylift. The bodylift gave me room for larger tires, the suspension lift didn't. It also has made a lot of things easier to get at and work on especially around the engine.

Nope, ground has no effect on the white/blue wire. If you have + battery voltage at the relay end of the white/blue wire, you should have + battery voltage at the fuel pump end of the wire. If you do in fact have + battery voltage at the pump end of the white/blue wire and the pump won't run, then the problem is with the ground side. If you really want to be confused, just know that the power flows from the negative post through the load(in this case the fuel pump) up the white/blue wire to the relay. When the relay is closed(energized) the current continues on through the fuse and then into the positive post of the battery. Lots of backwards thinking but that is how DC works. Basically the ground(the chassis and body of the car) is a big buss bar supplying the current that then flows back to the battery through all the wires.

Nice. It looks like it was kept inside and taken care of. It has 9k less miles on it than my 93 did when I bought it 21 years ago.

Sorry, hard to diagnose using a forum board. Can't really think of anything other than looking closely at all the vacuum lines and manifold. Don't forget the PCV valve. A simple check on it is to pull the oil dipstick while the engine is idling and see if there is a suction there. If there is, then it is likely the valve is bad.

A local friend of mine took his 99 in a few years back and they did the repair on one side. The other was ok. I spent 3 years at my local Nissan dealership and we would see an R50 come in for it every couple of months or so. The guys there told me a couple years earlier, they saw a lot of them and a few were deemed not repairable, Nissan bought those ones back. Not too bad since Nissan said Utah isn't a rust state(surprised us there, lots of salt and alkali here and still use a lot of salt in the winter on the roads) but still has the rust state recalls done here.

The ECU controls the compressor relay to switch on and off the compressor. It achieves this by using a power transistor commonly called a driver to drive the relay. It also uses inputs from the pressure switch, ambiant temperature, evaporator temperature, throttle position, and the HVAC control head. At least that is how the North American Pathfinders are. I suspect the Terrano is similar.

Nissan did have a recall for rust issues in the strut towers. Basically it was to inspect for structural damage. It being a recall, it is no cost to the owner for the inspection and repair if repairable. Might be something to look into.

If you can block off the intake side of the throttle body and the engine keeps running, you have a massive leak, more than just manifold or throttle body to intake gasket leaks. Try taking the hose off the brake booster and capping the hose. See if the engine settles down. If that fixes the idle, then you have a bad brake booster. If there is no or low suction on the brake booster hose at the booster end, follow the hose to the manifold and see where it is broken. At idle it should have a strong suction since it is straight into the intake manifold.

The white blue wire is the positive wire to the fuel pump. If there is a fault along that wire, then you don't have your 12v+(nominal) at the pump. The ECU simply turns on and off the relay. If you run a wire from the positive terminal of the battery to the white/blue wire where the relay plugs in, you should have battery voltage at the fuel pump regardless of the key position. If you do that and you have battery voltage at the pump, then it is likely a failed ground. I only say this because you said the pump runs when you feed power and ground at the pump, so that shows the pump is ok. So either the ground wire has failed, or the positive wire between the relay and the pump is your failure. Checking the ground wire is easy, with an ohm meter measure between the ground wire at the pump and a good body/chassis ground, it should be very close to 0 ohms. If so, the ground is fine and you can focus on the positive wire. Not complicated, just a bit tedious.

Yes, I did a relay mod to my 93 many years ago when the 3rd starter was acting up right after installing. I did some checking and found I was getting only about 9v to the starter solenoid. I looked at the wiring diagram and decided installing a starter relay like Nissan did for the manual transmission was going to be the easiest solution. It worked great for 15 years. Last year I installed a push button keyless ignition and that is when I found that the problem in my case was simply a worn out ignition switch. I don't have one in there anymore or even the lock, but still have the relay. It is just being triggered by the keyless ignition module now. Pretty sure that is what is going on with yours. The oil soaking into the starter is not helpful either. With my original engine I solved that issue with a remote mounted oil filter kit. Current engine is a VG33 with the filter on the front under the alternator, a much better location than the stupid idea of putting it between the exhaust manifold and the starter. The trans issues have been addressed. As has been said, when you install the torsion bars, have the weight off the front wheels while adjusting them. Not only is it safer and easier on the threads in the nuts and bolts, but easier to turn said nuts and bolts. Pay close attention to the bars and install them facing the correct way and correct sides. I can't recall exactly but I believe they are marked on the front end for left and right. Your repair manual should have that information. I have heard of and seen t-bars break because they were installed wrong. I believe there is a warning about that in the manual as well, but it has been so long and my mind is a bit fuzzy. If you can't find the info on the starter relay mod, I believe I still have a diagram stashed in a hard drive for it and I can email it to you. Just let me know and I will chase it down and send it if you like. Just not online as much lately, not enough hours in a day anymore.

I am pretty sure most of the better scan tools will work. I doubt there are very many Consult II's left that work in the shops. When I was at the dealership the one we had was glitchy and temperamental. It finally completely died about 6 months before I left. I found that my old Snap On Verus pro(I got it in 09 I think) did pretty much everything the yellow brick did, but faster and more. From what the security light is doing and the symptoms, it does sound like the NATS is your problem. From what I saw where I worked, I would suspect the antenna is failing or died. It is the ring around the ignition lock that reads the RFID in the key. Anytime that security light is on solid, the engine is not going to start. Enough attempts in a row with the system not accepting the key will lock the PCM and requires a reset with Consult or equivalent scan tool to unlock it again. At least that is what I found with the ones I worked on that were towed in because the lost key that was found again but was no longer programed was used. It happened a lot for some reason. The buzzing from the trans could be a relay, but if it is inside the trans, it is likely a solenoid. It could be a problem with restricted power as suggested, or it could be failing. Hard to say without knowing more.

If any of the plugs are yellow, they are for the airbag system. Depending on the year, you might have airbags in the seat. Also the donor might have had a seat memory system and your truck might not. To me, the simplest solution might be to transfer the subharness from your old seat to the replacement.

Does the security light turn on when you are trying to start and it is acting up? Just one of the possibilities. More likely a worn ignition switch though. I have seen a lot of bad ignition switches in older Nissans. You might want to check and make sure the battery terminals are clean and tight.

I recommend a pair of airbags will meet your needs that best. I put a pair of air lift helper springs in my Sorento a couple years ago to help the tired springs and give a bit more load handling. Have been working fine and cost less than new springs. Lets me pump them up a bit more when loaded and let a bit out when empty to help keep the ride good. The ones I got were Air Lift 1000 that I got on Amazon for about $80 and an hour or so to install, but I did it at work so was easier thanks to the lift.

Getting the engine to mate up with your trans is the least of your concerns. None of the power train management is compatible between a VG33 and VQ35. Can't think of much that will interchange on the engines either. They are completely different engines that honestly only have the same number of cylinders in common. You are better off just getting another VQ35 for your 01. Or I guess you can put your efforts and money into the 96, but it is your decision.

Looked it up, sensor failure is a common problem. Start by checking the power and ground to both sensors and if you have access to a 'scope, check the signal wire on each for a 0-12V square wave. The black with white stripe wire is supposed to have battery voltage, the black wire is ground. Left Bank signal is orange and right is yellow with green stripe. Check for short to power or ground on the signal wires as well. 5w-40 is a bit heavy for the engine unless it is quite warm, but shouldn't be causing your problem. Sticking valves, or phasers will cause the codes too, but usually notice a power loss if a problem there.

Sorry, not many of us here have a diesel or know much about yours. From the picture, it looks doable, but honestly don't know.

Not sure without doing some research on what all the SECU runs and affects. If you can still get into the car and operate it safely with the module unplugged, might want to try that for a couple days to see if the fuse is still blowing. If the fuse stoops blowing, then you found the problem. The way it is looking from what you have said here, I would suspect a failure inside the module is causing your problems

I know! They don't even have the crappy ones that you hung on the doors anymore.