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Maintenance & Repair 350Z up keep and diagnosing/fixing problems

Fluctuating Idle

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Old 12-16-2016, 08:31 AM
  #21  
C1Forged
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The issue with your injectors is that you're still on stock induction. You don't have boost to up your air intake to make larger injectors necessary to keep up with the extra air being sucked into the engine.

As for injectors, they play off a percentage. So if you have ID 1000s running at 20% duty cycle at idle, thats roughly ~200. If you upgrade to ID 2000s, you have to drop to 10% duty cycle to match the ~200. The issue at hand could be that your injectors are running at too low of a duty cycle, or that they couldn't be de-tuned enough to match your stock induction.

ere go... yes, your big injectors on a still N/A platform could be your problem. Especially since you've already mentioned that your tuner had issues with de-tuning the duty cycle to make the bigger injectors work.
Old 12-18-2016, 04:10 PM
  #22  
The_Assassin
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Originally Posted by C1Forged
The issue with your injectors is that you're still on stock induction. You don't have boost to up your air intake to make larger injectors necessary to keep up with the extra air being sucked into the engine.

As for injectors, they play off a percentage. So if you have ID 1000s running at 20% duty cycle at idle, thats roughly ~200. If you upgrade to ID 2000s, you have to drop to 10% duty cycle to match the ~200. The issue at hand could be that your injectors are running at too low of a duty cycle, or that they couldn't be de-tuned enough to match your stock induction.

ere go... yes, your big injectors on a still N/A platform could be your problem. Especially since you've already mentioned that your tuner had issues with de-tuning the duty cycle to make the bigger injectors work.
That you for the response. I am not sure the injectors were the root cause of my problems. The car worked fine for months on that set up. Another member on her has the same set up with no issues. Also, I have researched online and found a couple other 350z owners with the same issue that didn't change their injectors. Even when I went to trade in my car the dealer said he has seen a couple with that issue and they never seem to go away.
Old 12-20-2016, 08:32 AM
  #23  
C1Forged
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Originally Posted by The_Assassin
That you for the response. I am not sure the injectors were the root cause of my problems. The car worked fine for months on that set up. Another member on her has the same set up with no issues. Also, I have researched online and found a couple other 350z owners with the same issue that didn't change their injectors. Even when I went to trade in my car the dealer said he has seen a couple with that issue and they never seem to go away.
No two cars are ever the same. I had a header back straight pipe on my car for 20,000 miles without a single issue running a tune to ghost the o2 code for only having 1 of 2 sensors plugged in. Out of nowhere it started to surge at idle until it got to the point where once it got to operating temp, if you came to a stop the engine would stall out. Reverted to stock and no more problems.

Right now you have an issue, and you have mods on your car. Take the mods off one by one to revert to stock and one of two things will happen. 1) One of your aftermarket mods will be the issue... either the part will be bad/defective itself, or its just not working harmoniously with your Z. 2) you go completely back to stock and you still have an issue, proving that its not your aftermarket part, but you do in fact have an underlying issue.

Its all process of elimination.
Old 12-29-2016, 10:00 PM
  #24  
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Originally Posted by C1Forged
No two cars are ever the same. I had a header back straight pipe on my car for 20,000 miles without a single issue running a tune to ghost the o2 code for only having 1 of 2 sensors plugged in. Out of nowhere it started to surge at idle until it got to the point where once it got to operating temp, if you came to a stop the engine would stall out. Reverted to stock and no more problems.

Right now you have an issue, and you have mods on your car. Take the mods off one by one to revert to stock and one of two things will happen. 1) One of your aftermarket mods will be the issue... either the part will be bad/defective itself, or its just not working harmoniously with your Z. 2) you go completely back to stock and you still have an issue, proving that its not your aftermarket part, but you do in fact have an underlying issue.

Its all process of elimination.
Yes you are correct. I was able to take off my mods but then ended up selling my 350z and picked up a c7 corvette.
Old 01-03-2017, 08:52 AM
  #25  
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Originally Posted by The_Assassin
Yes you are correct. I was able to take off my mods but then ended up selling my 350z and picked up a c7 corvette.
In that case, congrats on the upgrade! Haha
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Old 01-08-2017, 12:24 AM
  #26  
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Originally Posted by C1Forged
In that case, congrats on the upgrade! Haha
lol Thanks man, take a look at it in the other vehicles section of the forum.

https://my350z.com/forum/other-vehic...-c7-vette.html
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