HELP! Car Wouldn't Start After Motor Swap - Need Reflash?
 

My Z is/was a 2003 Touring, ATI procharged with an Osirus tune. I just got another motor (also from a 2003 Z) swapped into my car. I won't get into details as to why since it's another long story. The issue now is that my car would not start. It cranks but there's no spark. So we're suspecting that the ECU is what is stopping the car from starting. All sensors are checked and even swapped to brand new ones. From what I was told from a few experienced shops is that a reflash is sometimes necessary especially when the year of the motor and the car itself don't match.

Couple questions...
1. Any idea besides ECU and sensors?

2. If ECU does need a reflash, only dealership could do it I believe, anyone knows of anyone that works at a dealership service shop that has access to this service?

3. If I get a ECU reflash, I'd lose my osirus tune since the data is stored in the ECU?

4. If I have Osirus tune done at one shop previously, does the license transfer to another shop?

HELP!

Check and make sure all the grounding wires are secure and are clean and also check the fuses.I blew a fuse behind the battery a few years ago and it did the same thing.

I'd post this in the engine section. Mid a is filled with a bunch of non car people. Plus you'll get 10x the views.

Plus 1 on the grounds. They can suck and cause all kinds of hair pulling problems.

Air
Fuel
Spark

With that you should get a stumble at the very least. Are you 100% for sure it has fuel and spark?


P.S you'd also get people who can read. after hitting post Saw your post again. Wtf. Lol. That's what I get for eating steamed pork buns while posting.

What about swaping Scott's or another persons ecu? I've never heard of an ecu needing to be reflashed due to engine swap. Maybe something to do with the chip in the key/motor/ECU?

Let me know if you want me to close the other thread in tuning and move this one to F/I ... the tech heads are in there and you are F/I after all.

If you're using the same ECU then you don't need a reflash. If you're using the ECU from the donor motor then you need a reflash because of NATS (chip in your key not matching).

Apparently there is no spark at all.

Mechanic double checked all fuses, wiring and still not starting.

check your coilpacks, Slim had to replace all 6 of his. It'd help to have another Z there to swap parts with.

Ethan, have this moved to FI section, may get more answers there.

Please do Chris! Thanks a bunch!!!

Well, in dave's car's defense, chances are they were all replaced to rule them all out, VS replacing just the one that needed to be replaced.

Just add it to the bill.

If a coil is bad the car should still start...

Its not the coils or needing a reflash...if it ran before then its a ground problem your mechanic is just not very good at finding.

Here's an update. So towed the car to Nissan and they reprogrammed the BCM? But the car's still not firing up. It's cranking and trying to start but it just would not fire up. While the car was at Nissan, the tech was able to get some read when the car was attempting the start and the timing was at -7 which is supposed to be WAYYY off. He said that could be the reason.

1. Does that -7 timing during crank mean anything at all? Variables fluctuate so I'm not sure if that really is the issue. The seller of the motor basically swore by his motor that it was running 100% before it was pulled with no issue.

2. Is the timing completely controlled mechanically or it has something to do with tune (keep in mind I am supercharged and running Osirus tune)?

3. Mechanic is gonna check coilpacks and spark plugs again to verify that there is spark. Any other suggestions?

4. Could someone let me punch him in the face just because?

I once tried to save money by using a hook up.

Never again.

Being cheap causes you to spend money. In some cases more money than if you did it right from the get go.... Plus weeks if not months of wasted time.

Good luck! Keith should know about the timing.

The timing is tuned by the ECU depending on driving conditions (advance/retard).

The Osiris tune would change the timing, but I do not know by how much as they play more with the air/fuel mixture.

Trying to look for more info regarding your car, I found this video where a twin turbo G35 was running the Osiris tune and showing the PC info.

The second graph on the laptop is the timing advance. Which it is 12-13 BTDC when cold (before top dead center).

I do not know what the guy meant by the "minus" on -7. If he meant 7 degrees AFTER TDC, then yes. That timing will not make the car work right. But it should still start IMO.
If he meant 7 degrees BTDC, then it should work fine.

Here is the video.

http://youtu.be/NmxhV6PfCqY

Also, I have looked at the specs on a 2003 350z and the timing is 15 degrees (plus/minus 5) at idle.

There is a huge procedure to check ignition and all the crap that comes with it (coils, wiring, etc...) So I am just trying to help with what I can find based on what you ask.

Good luck Etan!

^ Thank you so much! I'm really not convinced that the motor just has some crazy timing issue to begin with. The mechanic will check coils, wiring, etc on Monday.

Also, what kind of computer is that? Is this something that I can buy/rent/acquire for diagnosis?

It is just a regular laptop with a datalog software opened (probably from Osiris).

You can connect a regular laptop to your car with a regular OBDII to USB cable in order to datalog. Then with the software you just choose which graphs and numbers you want to appear live on your screen.

LOL that's my car and laptop :).

Assuming you actually have fuel and spark, if the timing really is that far off then you might have a bad cam and/or crank sensor, or the timing chain not installed correctly. Proper function of these sensors and correct alignment of the timing chain are how the ECU calculates timing and when to fire the spark and fuel. If it's so bad the engine won't start at all, you might not throw any codes since the ECU just doesn't have enough data to trigger any codes.