Chef-J

iTrader: (58)

No need info thru PM. Anyway i'm going to post here and share with people. If you can stand with your info, why not in public?

Here is his PM info__________________________________________

I read through your thread and to me it sounds like it was just a problem with the start up/idle map in the ECU. It is just like the long term/short term fuel trim map and is accessed when the car is initially started up. It determines the amount of fuel and timing needed to start the car and then sustain an idle.

After adding headers, you most likely increased air flow enough that there was not enough fuel to keep the car running. Since it stalled out almost immediately after it was started it took a few times to adjust the idle table.

I would say that simply starting the car the 4-5 times was what allowed the ECU to adjust for the headers. It probably had nothing to do with the reset procedures you performed.

Enjoy the new mods

-Chad


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Trust me it WASN'T simply starting the car 4-5 times. It took me whole couple days to fix this issue.

I will say, it's all depend with a car. But simply reset ECU won't hurt any, why not give it a shot? OP might not even need to reset his ECU, but add headers my car having rough idle, same as many members. I'm sure reflash or tunning will help my idle.

My info is from where i've done.

BTW: We are talking about whole intake/exhaust system install @ sametime. Not just add headers.

crg914

iTrader: (5)

Well, that's fine too. I was trying not to derail the OP's thread.

Either way, what has suddenly changed your mind to say "it WASN'T simply starting the car 4-5 times"?

In your other thread, sounds like you aren't sure. Now you're positive?

Also, of course tuning will help the idle. The ECU can only compensate so much before it's at it's limit. In most cases fuel trims can go from -25 to +25, in some cases +-30. While that sounds like a lot, with the base programming from the factory it may not be enough for ideal running conditions. Tuning or reflashing can give it a different 'zero' starting point so the range of adjustment is adequate to maintain a good mixture.

Of course every car is different. And it may not hurt anything, but I don't think its directly solving the problem.

I'm going to use arbitrary numbers to make this point so it won't be numerically accurate, but think about it like this. If after adding all your exhaust components the long term fuel trim needs to adjust to +17, then that's where it will end up regardless. Now if you reset the ECU it goes back to 0. Then it has to adjust to +17 from 0. If you don't reset your ECU it could be +4. Then it would only have to adjust from +4 to +17. Less adjustment. Conversely, it could already be -4, and have to adjust from -4 to +17 which would be more adjustment. This, however, does not necessarily mean it will take longer. The further off the adjustment it, the more the ECU will adjust at one time to compensate.

I have watched these things happen in real time on a scan tool while pulling vacuum lines, etc.

Ideally, I would like to watch the PIDs on a scan tool while someone has this problem, and start the engine a dozen times and observe the change.

So, reset the ECU if you want to, I'm just telling you from my own knowledge and experience, how it is supposed to work.

__jb

iTrader: (3)

When the ECU "learns" it is actually adjusting engine parameters to yield an emissions oriented mixture. The OEM ECU thinks your mods are problems that need to be accounted for.

If you want to get real performance from your mods, get a tune. The object is to set the ECU targets so that they "learn" towards performance oriented results, instead of emissions oriented results.

Chef-J

iTrader: (58)

Positive? And i changed my mine?? Dude, Every car act diff and OP is asking if he NEED to reset ECU with his MOD. And I said " he MIGHT "

You don't know what " MIGHT " means?

You must misread my other thread and "DATE".
Like it said i tried everything what i can do..

reseting ECU isn't easy but easy. Have you try? once you mis 1~2 sec, you gotta do it over again. That's what my other thread point at it, i missed many times, so i have to do it over again.

you get it? TURN ON OFF AND ON AND OFF didn't help my idle settle automatically.

And do NOT forget "it took me couple days to fixed this issue", i didnt 'lay around my bed couple days, whole couple days i've tried TURN ON and ON/OFF my car MANY TIMES.

Edit: Read again this thread. Non of posts you can call " misinformed "car guys".
My posts is base on my experience and other members also. You can go get a sets of headers/hfc/exhaust system/CAI and try on your Z, see how it works. It MIGHT works smooth or it MIGHT not.
Btw, i didn't even update my other thread that time.

-JLee