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Thread: Negative Idle Timing.

  1. #61
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    Quote Originally Posted by cobaltssoverbooster View Post
    so the idle etc scaler is being used in the idle airflow formula and if its off the ecu corrects it by removing or adding unneeded timing?

    if thats true when you change to le5 tb you increse it until the timing stops acting up and you have the proper etc area scaler value?
    Seems that way but isnt all the other TB's smaller than the LSJ? (other than the LS4 and such) So in theory the scaler should decrease from stock LSJ?

    The thing is I think its a band-aid. Something else has to be going on.

  2. #62
    I am sure something else is causing it because in the past my idle was fine and I never had to mess with my scaler.

    The only recent things that have happened are I replaced my flex pipe, my rear o2 sensor went bad so its been essentially deleted, and my optima red top was switched to a blue top. Other than that, the car hasn't changed besides gas and oil changes / plugs.

  3. #63
    Senior Tuner cobaltssoverbooster's Avatar
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    Quote Originally Posted by HNRClothing View Post
    Seems that way but isnt all the other TB's smaller than the LSJ? (other than the LS4 and such) So in theory the scaler should decrease from stock LSJ?

    The thing is I think its a band-aid. Something else has to be going on.
    yes ls4 thank you
    2000 Ford Mustang - Top Sportsman

  4. #64
    Did some driving and it's....odd.

    It seems like at idle my afr is really off at times. Like I will be sitting still and it will read 10s, then switch to reading normal 14ish in the same maf cell.

    Here is my question, what are the signs of a bad FRONT o2 sensor? Obviously the rears don't matter. Because I was watching my scanner and my front o2 was going up and down like normal and then it just flat lined at like 30mv or something drastically low for like 10 seconds and then "kicked" back in normal up/down to 850 or w/e.

    Really wish I knew wtf was going on with my car right now, brawr.

  5. #65
    Senior Tuner cobaltssoverbooster's Avatar
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    well there should be an 02 sensor check so look for a rich lean commanded and then check the actual following it. in the lnf its a square wave maybe you guys have a nice round wave that it looks for. also you can verify that flatline by looking at you external wb at the same time in the oscilloscope in the scanner.
    2000 Ford Mustang - Top Sportsman

  6. #66
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    So what ever came of this? I'm running the ZZP turbo swap and my idle timing like to hover in the negative range. I believe my idle air scalar is correct, but this is something I found doing my own research so I could be wrong.

    I've check for boost leaks and I don't notice anything out of the ordinary other than the evap solenoid making some noise with the intake pressurized.

    I've tried spraying some maf cleaner around the injectors thinking it may have been a bad seal but that doesn't seem to be the case.

    Any idea's on what else to check? I've attached my tune as well, but I'm fairly
    sure I've got it setup correctly.
    Last edited by CCrunner84; 06-25-2012 at 08:47 PM.

  7. #67
    Advanced Tuner Japeatr's Avatar
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    im convinced it was an air leak at the MAP sensor...when the car is running again, ill let ya know

    384whp/303wtq
    Built 2.0LSJ: TVS w/2.6, 1000cc, Stage 2 cams, custom fuel system, E85, Dual Pass, 3"intake, 3" Catless exhaust, CIA midlength Header

  8. #68
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    Did this issue ever get resolved? My car just recently started doing the same thing. Got two codes p1168 and p0082 on wot. Got codes for the throttle body and SCIP sensor so both were replaced with no change. MAF and MAP were also replaced and air filter cleaned, also with no change.

  9. #69
    Advanced Tuner Japeatr's Avatar
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    i fought this forever. proper injector tables (i ended up on ID1ks) then fixing that map sensor leak helped a ton.

    Car is about to be back with a new setup turbo and solid lifters and spray

    384whp/303wtq
    Built 2.0LSJ: TVS w/2.6, 1000cc, Stage 2 cams, custom fuel system, E85, Dual Pass, 3"intake, 3" Catless exhaust, CIA midlength Header

  10. #70
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    Quote Originally Posted by Japeatr View Post
    i fought this forever. proper injector tables (i ended up on ID1ks) then fixing that map sensor leak helped a ton.

    Car is about to be back with a new setup turbo and solid lifters and spray
    I wish I could say mine is the same thing but Ive taken everything apart and replaced almost everything except the barometric sensor. I cant find any vacuum leaks. I know its not my injector tables because it was running fine for a while, then codes started popping up and I noticed my idle was weird. The only thing left I can think of is that maybe my intake is damaged somewhere I cant see.

  11. #71
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    hi there; ı have 2011 aveo AT 1.4 car. I have a problem when engine hot and I press the breake red light, D or N shaking and rough idle.. ı change valve cover vent , sparks,cat, ignation set, throatt body and O2 bank 1 and 2 ( no voltage 2.O2 sensor) https://files.fm/f/rv3atf6er