Violator

Interesting to note that a guy who just did a 5.7 swap in a 02 sentra had a cps code and no start also, he fixed the no start by realizing his signal wheels were on the wrong banks (JWT Cams/wheels). If the stock signal wheels are different there's a good chance I did this too. He still has a cps code though and has already changed the sensor and is going to change the flywheel. I've read a lot about p0335 being related to 5.7 being untuned or only going after trying several crank sensors

I've been over the checklist a dozen times and everything seems to check out other than the codes I had for the inverters and lastly this crank sensor code. I even stated this as a concern beforehand and now here I am dealing with the problem I foretold.

I did however find http://www.rbannis.com/products/handmags/5.html these are used for demagnetizing cassete tape decks, this one is the strongest of its kind and seems like a viable option for demagnetizing each tooth on the plate. My plan of AC current unfortunately doesn't seem as easy to do as it sounded

User1

And you're positive you indexed the signal wheel correctly?

Violator

Yeah it was lined up. I got a new cps today. The magnet seemed like it had a stronger pull when I plugged it in. It's mistubishi as is my old one which actually had the Nissan shape molded into it, this one looks like it had that same molding burned off it.

I about took a baseball bat to the car looking for the key earlier and as I was writing this post I thought to try a spare I had cut idk if it was for this car or my old 4th gen, it doesnt feel like the right key when turning the ignition but it just barely does the job and the car turns over not enough juice left though. I got the battery charging up so I can play with it in a little and see if my CPS code is gone at least.

User1

Oh jesus christ in a cardigan, find the damn key and start it! I'll be here all night

Violator

You're too quick to reply I just edited the previous post as it gave me the idea to try an old spare I still had. do you have an app or get email notifications? And why are you always on at night?

User1

I am a vampire...

Violator

The vegetarian kind I hope? Hand-d-mag will be here Tuesday, I'll have it taken apart before then

User1

I had my engine and tranny in and out a few times too. Make adjustments, clearance issues, blah blah. So now the show's on hold...

Violator

It's a tight fit for sure. Yeah CPS code would come back after a couple tries cranking it. It's gotta be the orientation of the plate or ability to read the plate. If it comes down to it I hope this demag tool does the trick its the strongest available besides the NSA approved hard drive wipers $$$$$$. And it is considerably stronger than the rest of it's kind. I'll give each tooth a good amount of attention to hopefully remove any trace of magnetism


After some Google searching the '05 350z manual says to "avoid handling flywheel in a manner that will cause it to become magnetized". I really do think that's my problem, it passed through too many hands and it's obviously not that hard to do at least to the point it interferes with the signal

Slamrod

iTrader: (11)

what kind of flywheel did you use? Sounds dumb but many have two different holes in them for the alignment dowel off of the motor. One hole is for FWD and the other RWD - maybe its possible you aligned with the wrong hole? That would cause a crank issue as the signal plate would be misaligned.

Violator

It's a stock 99 flywheel (dowel pin on the crank only let's it bolt on one way, and I checked that it was lined up with the tdc mark) with a 5.5 timing ring cut off the flywheel and welded to a 3/8 bolt on spacer, resurfaced (regrettably) and balanced. I should have just gone with a new flywheel rather than resurface. But now the whole thing is balanced as a unit from a place 2hours away because everybody else around wanted a crankshaft to mount it to but this shop had done flywheels before by making their own mounting jig. The signal plate could of been magnetized several ways, from the junkyard it came from to the various hands it's passed through I wouldn't be surprised. plus the signal plate was bent on one end, whatever caused that as well as me bending it back could of caused magnetism.

From all the reading I've done into magnetism and materials I believe the hand-d-mag unit is more than sufficient, and method is just as important which I'm now educated on

User1

How can the crankshaft sensor sense the reluctor ring/signal wheel if it is not magnetic to some degree? This is all stuff I know nothing about. I would think the signal wheel would have to be magnetic. And how would cutting it affect the field? What was the process for modification? I understand striking iron rods can magnetize/de-magnetize, these were fun experiments in middle school. Beyond that, I'm the last person you want to talk to about it. I have the signal wheel from my 2014 motor somewhere. I'll have to throw a magnet on it and check it out.

Violator

If it's magnetized it would have the effect of trying to touch two magnets. A demagnetized object has the greatest attraction to a magnet because it has no magnetic field. Slightly magnetized objects can still be attracted to the magnet but not at the same strength because of the slight magnetic field. More in depth with terminology and confusing explanation below.

Boutta drop some knowledge bombs

It can be confusing to talk about magnetism. But when something is magnetic or magnetized, it has its own magnetic field to pull or repel ferromagnetic (almost completely randomized domains and very susceptible to magnets), or paramagnetic objects towards it(some of the domains are aligned and it's not as strong of an attraction as a ferromagnetic object because these aligned domains cause the effect of trying to touch two magnets, the magnetic fields repel eachother), this occurs when the domains have become aligned. Demagnetizing something is when you "randomize the domains" aka demagnetize the object

User1

I thought attraction or repelling of magnetized materials or objects was determined by polarity/pole orientation?

That was rhetorical. No need to answer, you're making my brain hurt already! I kinda understand, but my brain is on vacation right now. I truly hope your demagnetizer works!

Violator

You're right, but where would the poles be located on a ring? In short they would repel eachother. One side would attract and one side would repel the magnetic crank sensor. The poles would be on the opposite end of the diameter or axial poles? I didn't quite understand the explanation for that one. I misspoke on the ferromagnetism and paramagnetism just forget I even mentioned the terms they aren't crucial to understanding why a magnetized flywheel is problematic

The car sensor is a magnetic hall effect sensor reading the gaps on the signal wheel. Enough magnetism can throw this signal off and is warned against and been experienced by a lot of people and a lot of people don't know that "magnetism" was the reason replacing their flywheel solved their missfires and no starts (this one is also possibly related to the teeth for the starter if they somehow broke off). But anytime a flywheel causing a misfire is because the crank sensor isn't reading the flywheel correct, possibly due to a bent signal plate but I bet a badly enough bent signal plate is more rare than magnetism. Even rust can cause magnetism

User1

Lots of the sensors are hall effect. Which is why I guess I just assumed that which was being sensed was of a negative polarity, thereby pushing a magnetic field through the sensor as it passed creating an electromagnetic charge which then became the electrical signal being sent to the computer. You're really making my brain hurt here, dude.

Edit: Basically, that's my understanding. Please correct me if necessary.

Violator

You're trying to make this complicated and starting to give me a headache. The sensor does read the magnetic field, which changes with the highs and lows of the signal plate

I read (more like skimmed to sections of interest) a huge "guide" or PDF file on hall effect sensors from Honeywell. And there was a part that talked about the "target" material being ideally below 25gauss, which seems like ideally it should be demagnetized. I wanna say it would be difficult to manufacture a specific magnetic intensity while controlling the poles

Someone at my work who's into cars said their brother had to have a flywheel demagentized on what sounded like an older project car.

Where's the Nissan engineers at?

User1

I just thought the sensors and whatever was being sensed used like poles to create the charge. Like a generator. You're way over my head with this stuff. Hurry up and get that de-magnetizer thing and start this damn car lol

User1

Violator

Could of used some narration

Both poles are attracted to the teeth while it's seems the "neutral" zone is not, which seems normal.

Anyways my CPS still has a slight pull on the plate that can be felt when putting the sensor in place but I don't recall it being as strong of a pull as my 4th gen plate was, I think it's just residual magnetism that affects the strength of the magnetic sensor. On the 4th gen the sensor seemed to have a noticeable pull to the plate now the effect leans toward hardly noticeable

User1

Indeed it was. Neodymium magnet. The signal plate is very much magnetic. I think we may need to reconsider our direction with your no start issue. Is the crank sensor you have installed new or old?

Violator

Of course it's attracted to magnets it uses a permanent magnet sensor and I've been saying that the crank sensor pulls itself to the signal plate and has before I did the swap you can feel this effect when you're putting the sensor in. But to be magnetized means putting off its own magnetic field and being a magnet itself. And that's what the FSM warns against is letting the signal plate become magnetized


INTERESTING. Apparently the engine doesnt need the cps to run because it has 2 cam sensors to index timing unlike the 4th gen. do you wanna test this theory? Because 2 people said it didn't need it 1 said it does

User1

Ill do it right now. Standby

User1

Here ya go bro

Violator

Thanks you just saved me a lot of time ****ing around with a component seems to help with starting but isn't necessary for operation. Everybody seems to be saying the starter isn't grounded well enough and I'd have to say this is probably the next most likely issue

I've gotta make/buy a battery ground cable. It's like 3 inches short between the spot on the block and the spot it's SUPPOSED to go on the body, I've had it hooked up to the battery tray support for now. Plus I haven't gone over the torque specs for the trans and theres a little tiny ground by the trans mount for the life of me I couldn't get to "plug in/on" to the male metal piece on the trans it's like a little clip and the female part wouldn't fit over it like it had been stepped on or something I gotta get it opened back up a little bit

User1

Definitely address the grounds.

Violator

So my CKP problems were fixed just by swapping on 02/03 "5.5 gen" oil pans and crank sensor(apparently 5.5 pans/sensor work on 4th gen ECM but the 4th gen sensor is not forwards compatible). I had been focused on why I don't have spark, which even with the CKPS deleted I shoulda still been able to start. Ignition and injector circuits test good, NDS2 reports good pulse width to the injectors and a good start signal (tested this and ignsw signal), fuel pump pressurizes rail and runs while cranking, tried 3 ECMs, unnecessarily redid my cam signal wheels. Ran out of ideas and fixed my CKPS.

At this point I've concluded it must be the cam sensors/signal. My v2 nisformance inverters solved bank 1 and 2 cam DTCs. But without the CKPS I couldn't get anything other than 63.5 for cam advance on both banks(where it should be without CKPS), now I read 63.5 for a tenth of a second before bank 1 reads ~8degrees and bank 2 reads either 0 or between 4-6 and it would constantly bounce between those numbers. I decided to swap bank 2 sensor and that reading then became a solid unchanging 0 reading. I'm trying to get data on where those readings should be, but I'm fairly confident my answer lies here, especially since the cam sensors seem to be the primary input for spark

krismax

iTrader: (15)

Wow i have never heard of this "magnetized flywheel" How would someone do that by mistake? Usally dragging a magnet in one direction,magnetizes something. Why would someone do that?

Violator

You dont even have to drag the magnet, it's magnetic pull will align the poles on the target object if given enough time or strength or if the material has a low enough resistance to magnetism aka high "magnetic memory"

Some machine shops use magnets, and dropping it, rust, DC current, all of these things can cause magnetism on the small signal plate for the ckps. I actually saw the idea in old posts on this forum and also a big Reddit thread for a Maxima. The 02/03 FSM advises "dealing with it in a way that won't cause magnetism". Because the 5.5 ckps sensor and oil pans worked on 3.5 swaps with 4th gen ECU I figured that's what it had to be. I don't get how the 4th gen sensor/pans don't work with 5.5 ECU but whatever, problem solved

CMax03

iTrader: (3)

That piece of metal is the magnet not the flywheel!

User1

Huh?

schmellyfart

iTrader: (46)

So is it running now with the new pans/sensors?

Violator

After rewiring the ignition (ECM pin 43) wire to an on AND start power, because my car is actually a 99 and not a 98 as originally thought (8/98) whereas the diagrammed will was only powered in the on position. I've got exams and a big paper due next week I've got to buckle down on, but by then or following that I'd expect to see the car all back together and driving around the block. It's gonna be night and day between my 3.0 timing 1st gen de with a puck racing clutch