I'm going to commplain about my car here v.EvoVIII

Discussion in 'OT Driven' started by RyeLou, Aug 23, 2008.

  1. RyeLou

    RyeLou OT Supporter

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    Cliffs: Car idles at 4k after boosting to redline. No idea why. Read for details.

    I have an '05 Evo GSR. I bought it with a few simple mods, figured I'd add to it a little and leave it at that. Came with AMS turboback, K&N filter, Forge DV and MBC, Walbro pump and AMS tune. Things were great, wanted a little more power, bought some cams and a lower IC pipe. Cams and LICP went in no problem. I had to wait about a week and a half between doing the cams and getting the car tuned. It's my daily driver so I took it very easy. I only got on it twice....once to make sure everything was good right after the cams, and once a few days later. Other than that, just normal putzing around.

    So it's getting tuned, and on the baseline pull it boost and gets to redline fine, tuner lets off the gas and it drops to 4K RPM and just holds....and holds, and holds. It sat there for a good 10 - 15 seconds. Long story not as long, it keeps doing that. I've tested almost everything I can. Here are the facts:

    1. Doesn't do it at idle like in a parking lot, seems like there has to be some bit of load on the car

    2. The throttle cable moves fine and does not bind up anywhere. The throttle body does not stick open. I've had a scanner hooked to the car and the TPS reads the voltage correctly and does not drop out anywhere. The IAC is not the issue...I switched mine with someone elses who I knew was working and the problem stayed there. There are no vac. leaks.

    3. I disconnected the harness from the IAC and the problem went away..? I drove like that for a while (I'm waiting to get back with the tuner) but had some problems at idle when it got cooler out one night. When it's warm it's fine with it unplugged, but when it gets cold it idles for shit and will stall on me.

    I have no idea what it is. Because it happened while being tuned, the tuner looked at various things and nothing seemed to help. Told me to replace the IAC and if it didn't fix it to let him know. It's been 8 days since I was tuned now and I haven't heard from him yet...I've contacted him repeatedly. I can't think of anything else it could be other than something in the ECU telling it to stay there under whatever conditions. I don't know how it got there, but I can't really find an explanation for any of this. It's the only thing I can think of as to why it would work with the IAC disconnected but not with it plugged in.

    Any input?
     
  2. you know me

    you know me OT where the douchbags play

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    almost sounds like a massive vacuum leak
     
  3. RyeLou

    RyeLou OT Supporter

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    I know, but I've checked everything plus if it was I'd be having more issues than just that. It idles great with the A/C off and it idles how I would expect it with cams and the A/C on. If it was a vac. leak I would also assume disconnecting the harness to the IAC wouldn't change anything.

    It seems like it "should" be a whole bunch of things, but none of them make sense when you look at all the symptoms.
     
  4. deusexaethera

    deusexaethera OT Supporter

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    How about the RPM sensor? Is it reading correctly?

    Also, what happens if you reflash the ECU back to stock? If the problem goes away, then there's an error in your custom tune.
     
  5. art_VW_shark

    art_VW_shark OT Supporter

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    is it boosting while it's holding that high idle?
     
  6. RyeLou

    RyeLou OT Supporter

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    No boost while it's holding that idle. It sits at about 17 vac. which is not quite as much as it would while engine braking, but certainly more than idle.

    While it's there the RPM's show it's there, that is also reading correctly.


    I haven't reflashed it with a stock program yet. I was waiting to hear back from the tuner, and I thought he was going to be helpful but it looks like he's not going to help at all. I was just told about an hour ago that, "The tune looks fine and nothing in it looks like it should cause the RPM's to hang up". Kind of bull shit if you ask me considering I paid for it already (obviously) and I'm having that problem still and it idles for shit with the A/C on. I'm waiting to get my laptop back from my friend then will be buying EvoScan and a tactrix cable. With that I'll be able to flash a stock program back in to at least try it once.

    And on that note, with the mods that I have how shitty (or unsafe?) will the car run if I just take it to redline once? I told the tuner to email me the file of my car so I can also look at it, so I'll have it to flash back in anyhow.
     
  7. deusexaethera

    deusexaethera OT Supporter

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    How badly will it run? Well, it will be hard to control the speed if it insists on idling at 4000rpm even when in-gear; other than that, there probably won't be much difference.
     
  8. RyeLou

    RyeLou OT Supporter

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    It only idles at 4K RPM after boosting to redline. It idles great with the A/C off otherwise. And you can force it to drop RPM by shifting to a higher gear. As long as it isn't going to hurt anything too bad I'll flash a stock program in and see if it goes away. I'll only need to run it to redline once...it will either happen or not. If it doesn't I'll be lost all over again.
     
  9. notaniceperson

    notaniceperson -I'm an ASSHOLE!

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    Sounds like a mitsubishi.
     
  10. RyeLou

    RyeLou OT Supporter

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    Got a tactrix cable and hooked it up to my laptop. Ended up being the stepper table. I adjusted it and it works great now.
     
  11. InFesteD

    InFesteD OT Supporter

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    so the car is good now
     
  12. RyeLou

    RyeLou OT Supporter

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    Yes. No idea who/when the stepper table was changed, but it's fine now.
     
  13. deusexaethera

    deusexaethera OT Supporter

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    And the old-timers bitch about not being able to tune newer cars. :rolleyes: More like, the basic shit maintains itself now, and the complex shit can be tuned in ways that were impossible to do before computers. The thing has a stepper table? That's like an infinitely-adjustable throttle pulley that doesn't have to obey the laws of physics; let's see you do that with an LS1.
     
  14. PanzerAce

    PanzerAce Active Member

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    so....wtf is a stepper table?

    <- runs carbs and a mech dizzy
     
  15. deusexaethera

    deusexaethera OT Supporter

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    A stepper table is a table that correlates the angle of the gas pedal sensor to the angle of the throttle sensor. That way you can make the throttle move such that airflow actually increases perfectly linearly as the gas pedal is pressed to the floor, instead of making the driver's brain figure out how to achieve the same effect.

    The more advanced ones also can open the throttle more at first, when it senses the gas pedal is getting pressed faster than normal, so the car starts accelerating a few milliseconds sooner. Most of them also force the throttle to close when the brake pedal is pressed, no matter what the gas pedal is doing. That last one is a great safety mechanism in case the gas pedal gets stuck or the sensor breaks.
     
  16. RyeLou

    RyeLou OT Supporter

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    Don't know about that, but in this case this is the idle stepper table. The idea is when you let off the gas pedal after accelerating, it's what tells your car to decelerate at the rate it does. On my car with the program I have I can control how fast that is by adjusting the idle stepper table which uses the IACV (idle air control valve) if it needs more or less air to get the results. You don't want it to fall too fast so you can keep the rev's up when shifting at higher RPM's, but you don't want it to hang up either and stick at a certain RPM.

    In my case, the problem was the number that was in there was higher than it could read...and it didn't know what to do so it stuck at the last reading it had.

    I'll actually post what the graph looks like. It figures out where it should be on this table based on engine load and coolant temp.

    [​IMG]
     
  17. deusexaethera

    deusexaethera OT Supporter

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    Oh...heh...yeah, I guess there's more than one table like that. I saw "stepper" and immediately thought about the stepper motors used in electronic throttles.

    Well, whatever, glad you fixed it.
     
  18. RyeLou

    RyeLou OT Supporter

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    Me too.

    Not quite as complex as what you were describing, but the point stands. I needed a laptop and a $100 USB to OBD2 cable to fix the problem. I could tune any Mitsu or Subaru with this thing...it's pretty wild.
     
  19. deusexaethera

    deusexaethera OT Supporter

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    Yeah, I have one for VW/Audi/Skoda/Seat, it's called a VAG-COM. Of course, Bosch ECUs don't expose most of the tables to mere mortals like myself.
     
  20. RyeLou

    RyeLou OT Supporter

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    The Evo/Subaru crowd has a handful to pick from. I use EvoScan and ECUFlash. Evo scan is oddly enough used for everything despite the name.
     
  21. GuiltySparc

    GuiltySparc OT Supporter

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    I use romraider/ECU Flash for my STi :cool:
     
  22. pbw

    pbw New Member

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    I had same issue on idle after redline, turned out the bov was sticking open after hard blow off.
     
  23. PhoenixEvo

    PhoenixEvo New Member

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    Who was the so called "tuner"?? Clearly they r the FAIL tuner, however im just curious if its someone the evolution community already knows about or whole new moron that thinks he can tune.
     
  24. RyeLou

    RyeLou OT Supporter

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    The tune was fine. He would have had no reason to touch the table. My guess was because the stepper table is load based, after the last round of mods it had more load than the stock table allowed for. All is well now.

    Actually the tuner is pretty damn good.
     
  25. GammaRadiation

    GammaRadiation Active Member

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    This

    or EGR

    edit:
    Drive by wire FTL.
     

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