Cujucuyo

Hey guys, I replaced my crankshaft and crankshaft sensors recently (Hitachi CPS0005 and Hitachi CPS0008), this was probably two months ago, and I haven't driven out much since then, suddenly the engine starts misfiring (sounded like a V8 which was nice but it's not good, lol), I've had his happen before and it was due to a bad coil which fixed the issue once replaced, however at that time I got a check engine light which told me of the issue, I don't have any check engine light coming on.


The other odd thing is that the engine does this for a couple of minutes, 4-5 and then runs normally, it happened twice in a 2 hour drive I did today, very bizarre; Any ideas?


I heard you have to relearn the position sensors or something along those lines, maybe I missed a step after replacing the sensors?

813_350Z

Try using a scanner to see if you have DTCs. Codes may exist, but may not have triggered the CEL just yet.

Consider replacing those crankshaft and camshaft sensors with actual OEM sensors. Unfortunately, the symptoms you are describing are common when replacing these sensors with aftermarket models and occurs quite frequently. Although it is common to try to save a few bucks by not getting OEM sensors, it can create additional problems. It is a common case of "spend alot once, cry once".

Cujucuyo

Thanks I'll check with my OBD2 tomorrow see if anything comes up; The sensors are OEM, Hitachi makes them for Nissan:

813_350Z

You're right. That was my mistake lol.

As for the relearn, I don't believe there is one (or at least I have not had to). I replaced my sensors a few years ago and they were just remove, install, and good to go. No relearn required.

Let us know if you have any codes come up and what they are. If none then we will consider other options.

Cujucuyo

I just checked right now and no codes, did an erase even though there weren't any, re-scanned, no codes again; Seems like whenever the RPM go below 1000 it starts misfiring (not all the time, it's just that most of the time I've noticed this it's while I'm stuck in traffic) and as soon as I accelerate it normalizes after a bit; Spark plugs are brand new NGK Iridium (changed them in September) that I got from Amazon; The other culprit could be the Mass Air Flow sensor and it needs to be cleaned, but the thought that keeps nagging on the back of my head is when a friend whose a mechanic told me that if I was to replace the Crankshaft/Camshaft sensors there's an option in advanced OBD2 gadgets that has a "relearn alignment procedure".

813_350Z

Did this occur out of the blue? Or it did occur immediately following a repair/mod.

Have you gone through to ensure you don't have any cracked/broken/disconnected vacuum hoses?

I have never heard of, seen, or done any relearn procedure after swapping camshaft/crankshaft sensors. I could be mistaken, but just saying.

Cujucuyo

Out of the blue, after I changed the sensors it was pretty smooth, that was 2-3 months ago.

rustyschopshop

definitely double check vacuum lines, would not hurt to check fuel pressure. Actually doubting fuel pressure since it goes away at higher rpm but doesn't hurt to check.