Hi I drive a 2006 Nissan Sentra SER Spec V. I just swapped the engine with a JDM QR25DE because the thrust bearings fell out of the old motor 
Now I keep getting a P0335 code but itās only when I start the car (which takes foreverā¦ like you would expect with a P0335). Iāve erased it after starting and it doesnāt come back in as far as I can tell. Iāve swapped the sensor twice so far (with the crank- and camshaft sensors from old motor) and checked the sensors with an ohmmeter. The sensors should be fine. Could a weak starter be causing this even though it sounds fine. How could I check the starter without a āBattery/Starting/Charging System Testerā which the FSM calls for? My worst fear is the signal plate is different or broken.
Used engine?
Tester
Thereās two things that need to align to sense the position of something. The sensor, and the thing being sensed. If your crank position is sensed indirectly via the distributor shaft position, make sure the space between the sensor and the shaft is within spec. You have to use a feeling gauge to determine it. If it is sensed directly on the crankshaft or something bolted to the crankshaft (i.e. the flywheel), again thereās a spacing requirement. If the spacing is ok, check the pattern of whatās being sensed (on the flywheel usually) to make sure it isnāt worn. Sometimes with engine rebuilds the flywheel is cleaned with an abrasive and that wears the pattern enough the sensor will no longer sense the position correctly. So check for that.
Yes, itās a used engine. I couldnāt afford the $5300 to have a shop replace it with a reman. engineā¦ the carās barely worth $2900. So, I decided to do it myself. I honestly donāt think thereās a problem with the sensor plate (on the crankshaft). And it definitely wasnāt cleaned with, well, anything. I know itās poor practice but the motor wasnāt rebuilt or torn down. The wires look fine at the connectors too.
A worn timing chain/guides will cause that code.
https://www.rockauto.com/en/moreinfo.php?pk=1818440&cc=1432234&jsn=397
Tester
Another thing to consider is damage to the engine wiring harness during the transplant.
I made sure it was up and out of the way before I pulled the old motor, but thanks. Iāll look it over again.
Since it cranks a long time before starting, but eventually starts and runs ok, it seems more like a soft failure than a hard one. By this I mean the sense function works, but not perfectly. Itās like a person that canāt pass the eye exam for the driving test, but isnāt totally blind either. Just a little blurry vision is all. A good squint can sometime be enough to pass the test, but not always.
First guess is a failing sensor or too wide of gap between the sensor and what it is sensing. A faulty wiring harness or connector is possible, but less likely. This is something a good shop with Toyota diagnostic expertise could diagnose without much difficulty, so you always have that as a backup.
If that turns out to be the culprit, Iāll scavenge from the old motor. Honestly the old motor started better even without thrust bearings! I think this forum might be a lost cause. I was just hoping someone else might have had an issue like this in the past. If i canāt figure it out in the next week Iāll take it to a shop for diagnostic. I got out of the Navy last year and Iām going back to school now and not working, so I canāt really afford to start throwing parts at it.
Iām really hoping Iām just unlucky enough to have three bad sensors. Iām dreading having to pull the motor again and pull the crank. Why couldnāt Nissan just make the sensor sense the flywheel like on the VQās?! Lol!
Just curious, does the sensor sense something directly on the crankshaft rotating surface then, not the flywheel? Where does it do the sensing, at the front of the engine, up by the crank pulley, or the rear, near the flywheel? Or the middle?
The improved thrust bearing engine is hard to start, but the bad thrust bearing started straight away? hmm ā¦ Maybe those thrust bearings are over-rated ā¦ lol ā¦
In any event, thanks for your service, donāt give up, keep at it, and best of luck.
The long crank time suggests that there is no cam signal, the PCM will find #1 cylinder TDC by trial and error. Inspect the groves in the camshaft to insure they are the same as your old engine. Next perform a continuity test between the PCM and the camshaft position sensor connector.
Good idea. The crank sensor could be working, but the cam sensor failing. Even if the crank sensor works perfectly, the engine computer canāt figure out which is the compression vs the exhaust stroke without the cam sensor working also. Iāve never head of the PCM figuring it out by trial and error, thatās new to me, but it seems like it would have a 50% chance of getting it right just by guessing. Either that or just fire the spark plug on both the compression and exhaust stroke until the cam sensor gets fixed.
Yeah, thereās a āsensor plateā on the crankshaft inside the block. The cps is located in the back lower section of the block. And I canāt give up! Itās my only car and I canāt get a loan for another car because the GI Bill isnāt considered income!
I guess I know what Iāll be doing tomorrowā¦ Thanks!
Will, I figured out what was wrong. I mixed up the power steering pressure and the crank angle sensor. Theyāre in the same relative location and have the same plug type. I figured it out doing voltage checks. Probably should have started thereā¦ And I feel really dumb.
Yeah, that would do it. Thanks for letting us know!
Just āhot wireā the starter. An 8 or 10 gauge wire from the positive terminal to your starter/solenoid and the thing should start right up and run for a bit, if the battery is good. Connect the wire to the solenoid terminal first and then touch the battery.