Phantom-V

So i recently blew my motor in my SE max. I baught another motor and had it placed into my car. NOW, i have problems!!!

First, when the motor was placed in, the mechanic said that my car had a hard start and that the Crank sensor needed to be replaced. so..i forked out $97 and placed it in. No change

I then took my car to Nissan to a diagnostic test. They told me that when you change the Crank sensor you have to change both of the CPS's also. so i forked out more cash for those 2 sensors.

recieved my last sensor this past Saterday and was eager to place it in. placed the sensor in and prayed. Started her up....no response...WTF???

FYI...in order to start my car i have to unplug the sensor from the crankshaft. wait 10 sec for the engine to crank before it starts.

I have no idea after this motor was placed in why it wont start properly. i get little jerks here and there while driving and a loss of power....lots of power. does anyone have any ideas?

im taking it back the the mechanic on my off day from work and telling them i payed for my car to work so fix it. if any ideas, please let me know since my max is my only transportation at this time.

Phantom-V

Do i need a ECU reflash?

denny_1986

iTrader: (1)

dont know what exactly is going on but from what i've read on the forum, bad ignition coil(s) and/or the maf usually cause rough starts and loss of power

pmohr

iTrader: (26)

You a 6MT or an auto?

He installed the flywheel or flexplate incorrectly, sounds like.

He probably saw the CKPS code and assumed it was the sensor itself, not an alignment issue with the timing ring.

Phantom-V

when i unplug my crank sensor after about 10 sec the car starts. the MAF would be connected to the crank sensor?

ignition coil(s)...hmm, i'll check into that.

when you do anything to the VQ35 don't you have to do a ECU reflash?

Phantom-V

...really. I well let him know this ASAP. I'll get him to take it apat and try it again...lol.

6spd MT

RLW001

iTrader: (11)

Seems to me if you paid a mechanic to swap your engine it should run when he returns your car? Of course, there may parts/sensors from the original engine that may need to reused or replaced.

Phantom-V

Hopefully this will fix the problem. its a horrible feeling not knowing what was going on. I'll let you guys know if this will solve the problem tomorrow. any more input would be nice also...the more the better to tell him.

Thanks Everyone for the insight...

oldngivout

iTrader: (8)

If you paid a mechanic to replace a mechanically broken but otherwise formerly running engine with a different one, then you should have been presented a running car. Sure, things happen, but you paid for results and you should not settle for less. I would not pay for him to throw any more parts at it.

Phantom-V

oh he will. im not paying for a thing. Any replacement parts is on him for not fixing my car in the appropriate manner. I refuse to pay for anything further. Whole thing cost me $1877.00.

Phantom-V

so in the end guys it turns out that PMOHR was correct, it was the fly wheel. he didn't align it with the crank sensor on the tranny. got her back and she feels great!!!!!

VQP0WER

PMOHR is da man.

denny_1986

iTrader: (1)

+1
pmohr for president!

pmohr

iTrader: (26)

Roly

I'm having a similiar problem in which after I replaced both crank sensors, my 01 auto wouldn't start. It went from hard to start to no start. Took it to Pep Boys where I used to work after a day of diagnostics, they came back to say that the trigger ring on the flywheel was missing some teeth but wasn't 100% sure if it would solve the no start. Took it to Nissan and they're telling me that they think the timing chain may have stretched and they'd have to replace it then recheck. Dilema. I'm even considering an engine swap.... someone help please.

pmohr

iTrader: (26)

Did anything happen immediately prior to the car having these symptoms?

Are they known good used, or brand new sensors? Why did you replace these specific sensors, and not the CPS for example?

Throwing any codes?

Have you looked at the timing ring to make sure all of the teeth are there, and there aren't any majorly damaged teeth? Same for the crank pulley.

The timing chain having stretched is extremely unlikely.

Roly

i got a code to replace the front crank sensor, replaced it, car started fine w/o issues for a week. decide to replace the rear one as well and that's when it didn't want to start. the timing ring which i assume is on the flywheel was told to me was missing a couple of teeth. they called the timing ring the trigger switch. it's $280 from the dealer.

pmohr

iTrader: (26)

Front meaning the CKPS REF, I assume? By the crank pulley?

Why did you 'decide' to replace the rear one? Just because?

Again, used or new?

Have you not tried putting your old CKPS POS back in place, see if it'll start up then?

Roly

yes by the crank pulley. I decided to replace the rear because of the starting issues again. Both were new (Autozone), I put the old one back on and still no start. The only thing i can remember as of now is that the rear CKPS was loose not bolted down all the way. Also when at PepBoys both CKPS were replaced again just incase and still no start. Reading all of the timing ring issues around here is leading me to believe that the teeth missing or misalignement but it's got me stumped cause of the sometimes it would fire right up and and other times it would take a couple of tries prior to start.

pmohr

iTrader: (26)

So have you checked all of the wiring? Made sure the connectors are all clean without crap or corrosion in them? Checked continuity back to the ECU?

Roly

no, i haven't personally, but pepboys did and the mech at nissan did as well he even swapped the ecu and still got no start. this is haunting me.

pmohr

iTrader: (26)

So assuming they actually did (which you can't really be sure of) again, have you visually inspected the timing ring and crank pulley? Checked the CPS?

Kind of odd for them to say they tried a new ECU...be a coincidence for them to have one laying around that would work, as well as programming the ECU for it.

Wait, I think we've been going at this all wrong. Assuming that it's a CKPS issue. Does the security light stay on while cranking, or while the ignition is in the ON position?

Roly

Can't answer the last question until i have the car towed back to me. It hasn't in the past, but since it hasn't started i don't know. Well, the dealer did have the car for 4 days. I haven't personally inspected the ring on the pulley, but the only thing I can be assured of is that there were metal filings on the rear CKPS and not the front one.

Roly

yes i just noticed that the security light stayed on as it cranked. never noticed it before though.

pmohr

iTrader: (26)

If the security light stays on, it's a NATS issue.

Most likely it just needs the ECU reprogrammed to recognize the keys.

Roly

so the chip in the key needs to be reprogrammed?

Roly

is this a common issue if an ECU gets replaced? is there any way to bypass the NATS system to get it started?

Roly

or does the car have to be present to reprogram the key? The engine in the car isn't the original one and i don't know if the ecu came with the engine or it's the original. When i bought the car, it didn't come with a FOB and i got one and programmed it. To my understanding i have only 1 key. Can the chip code be erased and set to a new key?

pmohr

iTrader: (26)

No, the ECU/NATS need to be programmed to recognize the key(s).

If the ECU is replaced, it must be programmed, or you'll never start the car.

There's no easy way to bypass the NATS system. That's the entire point of it.

Yes, the whole car must be there...along with all of the keys you want to be able to start the car.

You don't program anything about the key, it's all ECU/NATS.

Roly

i'll take the car back to the dealer on Monday. I spoke to the service advisor about the possible NATS issue and he was kinda speechless but said he'd reprogram it.

Roly

I did this about 10 min ago and no luck, the security light has turned off, but still no start.

1)Try to escape from LOCK MODE(Happens if you try to start the car a few times without the chip talking to the ECU).
a.Turn ignition switch to "OFF".
b.Turn ignition switch to "ON" with WORKING key.(Do NOT start engine.) Wait 5 seconds.
c.Return key to "OFF".
d.Repeat steps b and c TWICE(total of three cycles).
e.Start the engine.

2)If 1) didn't work it MUST be towed into Nissan to have ALL the keys wiped and reprogrammed with the ECU.

Roly

This is gettting pretty frustrating. If the NATS reprogramming doesn't work, i might resort to fork out 6hr labor that the Nissan shop foreman said he needed to go through the car entirely. he said there's a 90% chance that he can find the cause and get the car started.

Roly

after 2 weeks of not being able to enjoy my car.. it's fixed. timing ring on the flywheel. i'm relieved that it's fixed, but what a headache. about the only nice thing the dealer did was give me a loaner. thanx for the advice and tips.

OHH NOES

iTrader: (3)

When you say your car wouldnt start was it cranking and not starting or was it not cranking it all? I think I have the same issue.

Roly

it would crank but not start. after x amount of failed starting attempts the NATS security system kicked in.

datdude20

iTrader: (17)

im having the same issue man...wtf man.....

jus put a 06 motor in my car and in order for my car to start the crank sensor must be unplugged....but my tach is not reading anything at all.....jus stays at 0 rpms

so what might it be????

maxboy325

iTrader: (35)

Is it drivable at all? Check the ring on the flywheel they seem to be very sensitive on those trans.

Child_uv_KoRn

iTrader: (7)

You shouldn't have that problem. I had an 05 motor in an 02 and it fired right up and ran good after knock sensor was replaced. But I'm gonna warn you, I doubt it's going to run right. Mine ran great when it was cold outside, but when it got hot, it was a complete dog. Brand new maf, etc. The engine was BRAND NEW.

datdude20

iTrader: (17)

okay.....i bought a new crank sensor and the car still wont start unless i unplug the crank sensor but now when i plug the senor back up im able to get a rpm reading...but the car run's like ****....now what???

pmohr

iTrader: (26)

Chances are it still isn't lined up perfectly over the timing ring, and when you plug it back in you're nudging it over just enough.

It should start with the CKPS not reading the timing ring, but it'll take 15, 20, 30 seconds to start up.