I intended to get some pics of the new setup and some vids fri night, but i ran into a little issue w/ the car(MOTOR IS FINE!!!!). Coming of the interstate the other night after doing a full boost run the car suddenly backfired and then shut off. Ever since i can crank it up and it will and run perfectly for a bit then out of nowhere it will start stumbling and then backfire and shut off. It seems to run longer when the motor is cold, but as the operating temp goes up it will not run as long. Yesterday i was able to pick it up from a bank parking lot and drive it all the way home (10 mins) and it ran fine, but then i cranked it up 30mins later just to let it run in the driveway and it started its **** again.

To me it seems it has to do with ignition timming do to the backfiring that is occuring. I am thinking either a cam position sensor or a crank angle sensor.

Any ideas?

 

I dont think it could be your crank sensors but I may be wrong.. When my crank sensors failed my car would not even start. I am sure you went thru all your fitting to rule out any leaks or loose pipping. I had my car do that once (what your explaining) but found vacum lines undone.. Just go thru everything and if that doesn't work. Get on line with your tunner and do a computer link so he can tap into your ecu so he can take a look..

Cheers
Luie

 

Thanks Luie, but i am not sure i understand the whole computer link up deal


So you are saying your car would start and run normally for a bit then just shut down? I would think if it was a vaccum issue it would do it immediately

 

We had to go through and clamp down all my vacuum lines.

You might have a sensor that is bad when hot. Or a vacuum line that is cracked and opens as everything warms up.....

good luck.

Tom

 

Yes sir, thats exactly what would happen.

 

bump

 

did you call Jeremy?

 

Do you have any CEL? Check that, it will show if it is a crank/cam sensor, or something else.

 

Sorry guys i forgot to clarify, i had a check engine light the other night after it started doing it, but yesterday morning on the way home i went by autozone to get the codes pulled and it didn't have a light nor did it show any codes.

I did talk to jeremy that night (awesome guy to answer his cell on a weekend night!!!) and i talked to him yesterday. He seems to think it could be cam position sensor also.

 

its NOT an issue with any vacuum lines. this i promise you. its definitely a weird electrical issue somewhere either in the harness or ecu. if you know anyone that has an 06 6mt Z, you should borrow their computer and try to plug it in and see if that gets rid of it. it could be a simple computer issue since it does it by time after start up.

the only other thing that we have seen is the wiring harness have a semi messed up wire that only really starts acting weird when its hot. im sure either of those issues wouldnt be to bad to fix.

sorry for the stupid little issue chris, i wish we could have kept the car just a little longer after its completion but i know you were anxious to get it back.

thanks

 

so you don't think it could be a simple sensor issue? I am going to leave work early today and see if i can run the car and get that light to come back on. If i can then i think i will have a better point to start searching from.

 

ok, this is a long shot, but I remember a post where the FCON closed loop was messed up and a car started running really, really rich. The individual talked to Sam who told him to flip a DIP switch on the unit to "reset" the closed loop circuitry or maybe turn it off? The post was on this site (I think) so you might be able to find it. Or maybe it will ring a bell with JT...

Good luck.

 

Chris ...check your PM !!

 

This could be a possibility as long as Jeremy is utilizing the open /close loop option on the fcon .

SAM

GT MOTORSPORTS

 

Hey chris ,there is not a lot of good info here to establish what could be wrong with the car ,go ahead and give a call when you get a chance .


SAM

GT MOTORSPORTS

 

Is this related to other 350Z's manufactured in the same (2006) year using the same ECU or, related to the specfic ECU (FCON?) controlling timing?

I am just curious how well various after market ECU really function to resolve electrical/timing issues once the engine is operating a normal temps for a while... (This may not be a isolated issue in either NA or FI but may be a issue with the newer NISSAN ECUs).

Anyone from the various after market ECU manufactures are welcome to comment!

 

It really sounds like the FCON isn't getting a signal that it needs. First, scan for codes (hopefully they will come back), and then someone needs to log into that FCON, and check that you are getting correct signals for TPS, Boost Pressure, Coolant Temp..etc..etc.

I once had a defective MAP sensor that would suddenly make the car run like total crap...out of the blue. 3 hrs on the road, and the car suddenly died. Finally was able to catch it happening while my laptop was hooked up, and we figured it out. Once you reset the car, it was normal again. So maybe it's a weird electrical issue like that.

 

This has nothing to do with the abilities of the Fcon .... There are tons of cars 06 and newer running on this puter. We dont even know if its the Fcon thats causing his problem. I am sure Jeremy and Chris will figure this out.

BTW::All the top EMS on the market have no problem controlling timing either

 

In your experience: Is this a potential electrical issue (electrical feedback?)that is a specfic problem with 2006 350Z ECUs?

 

yea that is what is starting to point towards, either that or the ecu is fubared.

I checked the fuel pressure and everything looked good there. I was able to run the car for about 15 mins and drive it around the block and vaccum looks good. I am still not getting any codes which is pretty strange. I also had to change my wb02 sensor today, but i can't get the damn thing to work(it will not calibrate).

The issue itself is deff temprature dependent. Once the car got hot today it would not even run. I would crank it up and it would immediately start stumbling, but when it was cold the car ran like a champ(idle is very smooth, no odd noises).