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That sounds like a bad sensor and not a wiring issue. When a CMP or CKP malfunctions but doesn't go "flatline," it will cause no-starts because the ECM is confused about when to fire the plugs and injectors. Disconnecting the bad sensor flatlines it and allows the ECM to run using the remaining good crank or cam sensor without being confused.
 

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or more so, could the ring be damaged? The car seems to run fine without any weird sounds so I assume pieces of metals aren't flying around in there.
The cam reluctor on an MR is machined into the end of the camshaft, so you'd be in big trouble if that was the problem. It is possible you have some magnetic crud built up on the reluctor teeth (or on the tip of the sensor) that's preventing proper triggering, but that's easy to check for and clean up by removing the sensor and bumping or hand-turning the engine. The most likely answer is just a sensor that's getting weak.
 

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You'll need some safety pins for back-probing the connectors, the way the ESM tells you to check it is incomplete. They also don't mention anything about pin-fit, and that's something you can also check with an 0.025" diameter safety pin. You may end up needing that since the sensor is probably falsing and not dead, but start with any old pins and we'll see if you need a specific one.
1) Check voltage between G/Y and BR with the sensor disconnected and the key on. You should see right around 5V. If not, check from G/Y to the battery ground. If you get 5V from the battery ground, but 0V when using the the BR wire, then BR is broken. If both grounds give you a 0V reading then G/Y is broken.
2) Check voltage on R with the sensor disconnected. You should also see 5V there, but the voltage is coming through a pullup resistor in the ECM and not from the 5V supply (AVCC). If you see 0V then either R is broken or there's a problem in the ECM.
3) If steps 1~2 check out, back-probe G/Y and BR with the sensor plugged in but removed from the valve cover. Repeat step 1 but using the back-probes, keeping the sensor away from metal. If G/Y reads much lower then you have resistance in the G/Y wire. If BR reads much above 0V then you have resistance in the BR wire. If R reads lower then it's a bad sensor, new or not. Resistance on G/Y or BR can be in the wire or at the ECM connector pins, so that's where pin-fits come in.
See what you find, and if 1~3 don't reveal anything, I'll show you how to remove the backshell from the ECM connector so you can check there.
 

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You're back-probing both wires with the sensor connected, so the sensor is drawing operating current the way it would with the engine running. Voltage doesn't always tell you anything unless current is flowing. Here's what a "back-probe" means:
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You're sliding the safety pin in between the rubber and the wire to make contact with the pin without removing the connector. When you repeat steps 1~2, you'll be touching the safety pins instead of the connector pin. I.e., for the first part, you'll touch the safety pin on G/Y with the red meter probe and the safety pin on BR with the black meter probe. Since current is flowing with the sensor connected, if the readings are different from what you measured when disconnected, it means there's resistance in the circuit. That's known as a "voltage drop" test.
 

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The G/Y and BR should read the same connected or disconnected, if they differ by more than about 30 millivolts (0.03V) then there's a resistance issue. The Red wire may be a bit lower depending how much the sensor leaks, but it shouldn't be lower by a lot with the sensor away from metal. The way that works, the sensor has an internal transistor that "overpowers" the pullup resistor in the ECM whenever it sees metal pass by, pulling the signal line to ground. Unfortunately the sensors are very precise and also directional, otherwise you could check them just by waving a metal tool in the vicinity of the tip. That doesn't usually work with the type of Hall sensors Nissan uses.
 

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That test will tell you if the sensor is working, but not whether it's working well or half-a$$. To answer your second question, it isn't uncommon for Hall sensors of any type to be temperature-sensitive. I've seen ones that worked cold and no-started warm, and others that worked warm but no-started cold. Sometimes the mechanical clearances warm/cold contribute to that, since all Halls are very sensitive to the gap between the sensor and the teeth. And of course everyone has heard some nightmare story about wiring that's broken internally and only loses contact when hot or cold, and that can truly be a nightmare. If you think temperature is a factor, one way to find out is the test in the video performed both cold and warm. The sensor output voltage should show little or no change.
 

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So I was just out messing around with it. It cranks and catches and dies, but then I can try again and it almost dies and I catch it with the gas pedal feathering it and it revs up to 2-3k and the settles down normal. Should I do the Throtfls body relearn and accelerator pedal procedure for sh*ts and giggles?
And an IAVL, yes. IAVL will be the important one, that's what calibrates the MAF and synchronizes the MAF with the TPS. It certainly can't hurt.
 

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A fishing magnet through the sensor hole works fine for capturing metal debris on the reluctor. Anything that isn't metal isn't a worry.

Checking for shorts to ground or power involves taking both ends of the wire loose and ohming to battery+ and battery-. With both ends loose, if the reading isn't infinity (or at least megohms) then there's an insulation failure inside the harness. Where wires run in a bundle like the 3 conductors on your cam sensor, it's also a good idea to ohm each of the wires to one another.

Here's how you get the connector at the ECM loose and remove the backshell. These pics are of a TCM connector, but the ones on your ECM will be the same sort:
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Yep, exactly. I'd keep any eye on the reading and not just use the beeper. Sensor wires should read below 1 ohm, if the reading is higher it's usually a hint that the wire has or is developing a break.
 

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Ohms is good for checking for insulation failures, but the best way to verify continuity is actually with differential voltage and not ohms. Back-probe both ends of the wire and put the red probe on one end and black on the other with the key on, engine running if possible. If the wire is in good shape then you'll see a few millivolts at most between the ends. More than that means there's resistance in the wire which is causing a different voltage at one end than the other. The advantage to doing it that way is you can "wiggle test" any wire that gives you suspicious readings while the engine is running, and often locate the break that's causing the issue.

You should probably do a pin-fit check too, while you have the ECM connector loose. Find a size of safety pin that drags a little when inserted into the female cavities (don't use any real force, any pin large enough to need force can actually damage the pins). Then check all 3 of the pins for the sensor and make sure they all drag. Pin-fit issues are usually caused by the tiny leaf-spring inside the female connector breaking off or fatiguing, so a bad pin won't give you much or any resistance compared to the pins next door.
 

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The TPS or APP are unlikely to be involved in a startup problem. The ECM also looks at the IAT (Intake Air Temp) during startup, otherwise I think that list is correct.

The ECM should have color dots on the studs that engage the connector levers, and the connectors themselves will have colored front shells. One will be black, one brown, one gray. If you look at the layout of F25 on the wiring diagram, you'll see a little "BR" underneath the connector ID. That's the Brown connector.
 

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Alright so the cam sensor wires will be in that connector?
Yep, just like the diagram. The diagram shows a "Harness Side" view (where the wires enter), so when back-probing that's the view you'll use. Looking at the face ("Terminal Side") to use the ohmmeter or do pin-fit checks, it will be mirrored. You can use the location of the larger terminals 73~80 to get the connector oriented properly vis the diagram.
 

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It's normal for the pump to "blip" on for a few seconds and then quit when you turn the key on without starting the car. That's a priming mechanism to make sure the rail is full for starting, but keeps the pump from running unnecessarily with the engine stopped. But it still should do that every time the key is cycled. If it doesn't then you may have a weak pump.
 

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I've never done one on a Nissan by hand, at the shop we use a Nissan special spanner tool and an air impact. In the bad old days we used a brass chisel and a heavy hand sledge, but make sure it's a brass chisel and not steel (no sparks).

This spanner on Amazon looks pretty sturdy for $24, and I guess if you have Prime you can get it quickly:
 

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Like I said earlier, a safety pin the right size will work fine. Get an assortment box from Dollar General or Walmart, start small and work up until you reach a diameter that drags slightly. The factory pins are 0.025" nominal, so if you have a caliper, find one that's close to that. The drag you feel will be the leaf springs inside the female terminals. If they're all healthy then they should all drag about the same. Check both ends, the bad fit could be in the sensor connection too.

There's one other thing you should probably try before condemning the wiring. Take the screw loose on the sensor, turn the sensor 90 degrees and try to start it. If the problem goes away then you might be getting wrong parts for some reason. Have you been shopping using the Nissan part number from Nissan EPC, or by make-model-year? The latter is almost always a mistake.
 

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Go to NissanPartsDeal.com and plug in your VIN. They're a consortium of Nissan dealers marketing on the internet, so their dbase and drawings are identical to Nissan EPC. The p/n you get from them will be exactly what your ride was built with.
 

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Alright I'll do that. A question though why did the sensor work when turned at an angle? I started the car after waiting a day and the sensor still angled it started like normal?
Any Hall Effect sensor is magnetically active, and all magnetic fields have a polarity. Most Hall sensor IC's are constructed to work best in a certain polarity orientation, with or across the field, and south or north. That doesn't mean the sensor won't function in a different orientation, it just won't work as well as it should. Many aftermarket manufacturers cut corners by making their IC's work in orientations that they really weren't designed for but still work "good enough" in most instances. That's most of the reason some people have grief with aftermarket Halls but others work fine and have no issues. You can't exactly x-ray the sensor and identify the silicon to see if it's set up ideally for the design of your reluctor wheel.
 
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