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-   -   2002 GXE won't start (https://x.nissanhelp.com/forums/sentra/20537-2002-gxe-wont-start.html)

Island Jim 11-10-2011 02:01 PM

2002 GXE won't start
 
I have a 2002 Sentra GXE, manual tranny, with approx 101k miles on it. Recently, I started experiencing hard starts, which then deteriorated into periodic stalls immediately after starting (once stalled, I could always start the car after waiting for 5-30 minutes). Before long, the car started stalling while driving. The last time it did this to me, I managed to (barely) get it home and park it for the night, intending to troubleshoot it the next day. Ever since that evening, the car won't start.

I have tried quite a few things so far to try and pinpoint the cause, to no avail:
1 - new plugs
2 - new crank sensor
3 - new cam sensor
4 - checked for spark -- NONE
5 - checked for injector pulse (w/screwdriver to ear) -- NONE
6 - did NOT do fuel pressure test, but clearly smelled fuel while cranking
7 - sent ECM to (seemingly reputable) repair/rebuild company in FL (they said they could find no errors on any of the circuits
*Note: SES light DOES come on
8 - read several forums here at nissanhelp.com and checked for various voltages: i am getting 12v at coils w/IGN ON; however, i don't get any voltage readings at the ECM harness on terminal #31 (ECM relay) or terminal #67 (Power supply (backup) - whatever THAT is)

my main questions at this point are:
1 - if the ECM relay is bad (not sure it is, maybe i checked it improperly?), would i still be getting 12v to the G/W wires at the coils?
2 - where is the ECM relay located?
3 - is there a "spare" or duplicate relay somewhere in the engine compartment that i can temporarily swap with the ECM relay as a test?
4 - am i missing something more obvious here????

one request: i am just your average DIY mechanic & not an electrical wizard by any stretch, so if anybody thinks i should retry some stuff that i've already tried, by all means suggest that! also, if you're referencing fuses, relays, wires & the like, please be as specific as possible about location, coloring, etc.

Thanks in advance for any help you folks can provide!!!!

NissanTech 11-10-2011 10:26 PM

1 Attachment(s)
1. The relay powers two wires, one for the ECM (W wire) and the other for the coils (G/W wire). It's possible that the one part of the relay is OK and the other one is not.

2. Passenger side, by the kick panel. See attached image.

3. Not that I can remember, once you remove the relay you compare it with the relays in the relay box.

4. The ECM relay it's defenately a good start.

nrgjoel 11-11-2011 05:00 AM

fwiw Make sure you have 12v+ constant at the ecm relay to the red w/black stripe wire. I had a very similar problem with the relay not powering up the ignition coils. Also, there are three relays in the passenger side undder hood relay box that are tan. They are all the same as the one used for the ECM if you want to swap out one to test.

Hope this helps

Island Jim 11-12-2011 09:54 AM

Thanks a ton for the replies, guys. I worked on it all this morning... swapped relays, tested that red/black wire (which was indeed getting continuous 12v), and still no luck. I decided to retrace some of my earlier steps...

I remembered when I had tested for spark the first time, I was doing it alone and had to try to rig up this little el-cheapo screwdriver-looking thing with a black alligator-clip lead and the title "spark tester" on the side so that it was inside the plug wire but still visible through the windshield... and at that time I saw no little red light to indicate spark. I even tried it on my other car to make sure the thing wasn't defective, and it blinked like crazy, so I knew it was Ok. But, as I said, nothing on my Sentra.

This morning, I asked my wife to turn the key while I crammed the tester thingy into the plug wire, and the little red light came on (plus I git a little shock in the hand that had the coil in it, what an idiot!), although i must say it wasn't a fast on/off flash like on my other car...

Anyway, I was glad that I had re-tested this (all for wires gave me the same results), and went out and bought a large can of starter fluid, emptied half of it into my intake while my wife was turning the engine over, and NOTHING! I was SURE it had to be some kind of fuel delivery issue (once I had seen the spark tester light up), but I guess not...

I'm pretty stumped at this point... any more ideas? Am I getting spark, but just not ENOUGH spark? Could it be that ALL the coils went bad at once? That seems ridiculous to me...

Well, sorry for the mis-info earlier about the spark... but thanks for your help, and for any other ideas you guys might have!!!

bennyb53 11-12-2011 10:38 PM

You said SES light is on. Scan the ECM for trouble codes.

Island Jim 11-13-2011 12:03 PM

Thanks, Benny... I forgot to mention in my first post that I had borrowed an OBDII scanner from a friend a couple of weeks ago, and it showed 2 or three codes, one for the crank sensor (which is why I immediately changed that sensor), one for the IAT sensor, and maybe(?) one other that I can't remember right now, but whatever it was it didn't seem as if it could possible cause a no-start condition. I cleared those initial codes, replaced the crank sensor, and tried to start the car. After it still wouldn't start, I scanned for any new codes, but it came up clean.

Is it possible that even though I'm getting spark, it's too weak? I have turned the engine over quite a lot since this first started; should I maybe try again with the starter fluid, except this time get a jump from another vehicle?

Thanks again, everyone, for your help.

JudoJohn 11-13-2011 02:53 PM

You should also change the cam sensor when.

bennyb53 11-13-2011 06:29 PM

I agree with JudoJohn. The cam and crank sensors work in tandem. And you also replaced your MAF sensor. Also check your PCV valve. Shake it close to your ear and if you don't hear a rattle, its clog, replace it. Even if you hear a rattle and your over 75k miles, go ahead and replace it.

When you turn your ignition key to on, do you hear a buzzing sound. Its your fuel pump powered up, if no sound, your fuel pump has failed. If you hear the sound, do the fuel pressure test.

It would have been good to know what that third dtc was. Even if one of your ignition coil is not firing you engine would still start. You'll just have a misfire.

Island Jim 11-14-2011 05:07 AM

Thanks again guys for the replies. As far as the cam sensor goes, I had already replaced it along with some other stuff (see my original post), but none of that stuff worked. And I'm happy to check the PCV, but I didn't think it was possible for a bad PCV to cause a no-start condition (or a bad MAF, for that matter)... am I wrong about that?

I'll check for the fuel pump sound... but that raises another question: is the "starter fluid" test not really an effective way to determine whether the problem is related to fuel-delivery? if not, fine, i'm just curious for future reference...

Thanks again, everyone, your help is GREATLY appreciated!!!

Island Jim 11-15-2011 04:53 AM

Checked for sounds from the fuel pump last night, and something in the tank area is making a whirring sound for about 2 seconds every time the key goes to the ON position, so I'm assuming that's the pump... I'll try to do a pressure test tonite.

OilCanObserver 11-21-2011 02:08 PM

try this: disconnect the big cable (wire) from the alternator. then try to start the engine. it seems weird but the alternator is going bad.

streamcast 11-21-2011 04:33 PM

What kind of spark plugs did yiu put in? The SES light is definitely coming on? Also it would be great to know what voltage you are getting on the wires of coils I know one is power 12 volts I think it is the second wire, but check the voltage on all three wires and post. I am not sure which one is the signal / switching wire. Also the engine could be flooded you would have to remove all plugs dry out cylinders and place a a tea spoon full of oil in each cylinder and change oil. Also very important. Crank engine 2 to 3 times. Remove fuel pump fues when crank and engine attempts to start push fuse in at same time may have to depress accelerator. If engine is flooded this procedure should start the engine\

Island Jim 11-22-2011 06:41 AM

Thanks for these latest suggestions, guys. I'm out of town all this week, but will be back Dec. 1st and start looking at it again, post those voltages, etc...

I'll have to pull one of my plugs to see which kind I bought, cuz I'm drawing a blank on that right now... Bosch platinums, maybe? Can't remember...

Happy Thanksgiving everybody!

aap1979 11-23-2011 09:11 AM

Engine Control Computer
 
I posted this elsewhere but I am currently having a problem with my 2002 Nissan Sentra GXE where the engine is dying when the engine reaches normal operating temperature. I took it to my mechanic and the first thing they did was change the Throttle Position Sensor because codes were being thrown that it was failing. With the new sensor in place they test drove it and it was still dying. After ruling out a number of other things, they started checking the computer and found that it was shorting when the engine reached its normal operating temperature so basically it could be driven for 5 or 10 minutes before ecxperiencing problems. Once the computer shorts it kills the engine. I was always able to get it to start again after it died. My mechanic had someone bring in their Sentra experiencing the same symptoms so this is why he thought to check the computer but apparently it is a common-enough issue.

I am not a mechanic either and don't know how to test this but maybe someone else can give you that information.

In case you were wondering, it will cost me $1000 - $1100 when they are finally done. The computer is $400 - $500, the Throttle Position Sensor is $100 and then dyno and labor.

streamcast 11-23-2011 12:49 PM

What are the codes. When the vehicle stalled was the engine light on, when you turn the key to the on position after stall was the engine light on. These vehicles are also known for electrical issues as well.


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