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What would you do?

Discussion in 'Tuning À la carte' started by robert presti, Jul 30, 2019.

  1. robert presti

    robert presti Member Established Member

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    I have a car that runs great hot, well after 2-5 minutes . It will stall when braking any time before that. A 2000 mustang GT and I'm thinking the hydro boost brakes create just enough draw on the power steering pump to stall the engine. I don't believe this car has a switch to add rpm for that, though some fords did. It is around 13.5 or so cold , so is that just to lean while the engine is cold or should I raise the rpms till it doesn't stall. Which the rpm is around 12-1300 and climbs a bit as the engine warms until it switches tables, warms up and then idles to 1000 rpm. Never stalls after that. I am running 91 pure gasoline at the moment. And by cold start I'm talking a 70 degree day first start and drive away.
     
  2. slo984now

    slo984now AKA 01yellerCobra Established Member

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    I'm not totally following. Are you saying the engine stalls when coming to a stop when it's cold? Then when it's warmed up it's fine? Is the 13.5 the commanded AFR when it's cold? Is the 1000rpm the idle when it's warmed up? That sounds pretty high if so.

    You need to tell us the whole set up so we can give more informed answers. Stock engine? Stock with a blower? Massive cams? Return or returnless fuel system? Etc.
     
  3. robert presti

    robert presti Member Established Member

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    Built engine with a d1-sc super charger. The engine can run 850 rpm warm, but not if I hit the brake hard, so that's why 1000 rpm idle . The issue starts the second the brake pedal is pressed... Same for my cold stall issue. 13.5 is what I'm seeing on the wide band cold and around 15 warm. The cams are stage 3 or something like that and the car is now return fuel. The one odd thing about the engine is it is suppose to be 8.5 to 1, so it might struggle with big cams down low
     
  4. slo984now

    slo984now AKA 01yellerCobra Established Member

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    Big cams cause all kinds of issues. It's one of the reasons I stuck with stock cams in my last engine build. Are you doing the tuning yourself?
     
  5. decipha

    decipha Active Member Established Member

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    if it stalls while braking when cold or anytime really that means your idle air is not dialed in

    you dont add rpm for the brake load you add air, yes it has that ability.

    your afr sounds fine, fuel is not the problem, air control is

    if idle is 1200-1300 while warming up thats plenty high already

    there is no switching idle table

    you shouldnt raise the base idle to 1000 instead of your 850 just for the brake, thats completely half assed

    compression ratio has little affect on idle and idle loads. With the ability to idle at 850 its obvious the cams are fine.

    With the stock ecu there is really no limit to the cam you can run as the stock ecu can be programmed to operate perfectly.

    best bet is to contact your tuner and let them know whats going on. It should be a simple fix.
     
    Zemedici likes this.
  6. robert presti

    robert presti Member Established Member

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    yes I'm trying this myself. Unless I peg the MAF on a wide open pull, I think I have the car set up nice aside from a few tune issues. The biggest thing was getting a big enough recirculating valve for the super charger and locating it before the intercooler.
     
  7. robert presti

    robert presti Member Established Member

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    Some mechanical issues has been changed so now I might not have to worry about a runaway idle. I also have the dashpot set close to as low as possible , because I hate pushing in the clutch and the engine flaring and free revs that take forever to settle back down. I just wasn't sure how rich an engine should be cold. I'll look into IAC and dashpot function a little more. What sucks is I love the way every is working now, other than having to drive 5 to 10 blocks to not have a stalling issue. The car is set to idle table at 0 miles per hour and can be moving some what fast when it will stall hitting the brake when it would run other wise. Target to control idle error is set at 400 rpm error , and I'm not sure if that was me or SCT value to prevent a hunting idle. Is that extreme?
     
  8. mysticsvt

    mysticsvt southernmustangandford Premium Member Established Member

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    Every time I see the title I'm like....bahahaha

    What would you do if your son was at home
    Crying all alone on the bedroom floor
    Cause he's hungry
    And the only way to feed him is to, sleep with a man for a little bit of money
    And his daddy's gone
    Somewhere smokin' rock now, in and out of lockdown
    I ain't got a job now
    So for you this is just a good time, but for me this is what I call life
     
  9. robert presti

    robert presti Member Established Member

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    My son is dead so I guess I have the luxury of that as well? WTF is your point ? I posted a question about tuning a car in the tuning section.
     
  10. mysticsvt

    mysticsvt southernmustangandford Premium Member Established Member

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    Lighten up buttercup. It's just a damn song that your title reminded me of. But I am sorry you lost your son and had no intentions of upsetting you.
     
    Last edited: Aug 1, 2019
  11. robert presti

    robert presti Member Established Member

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    I'll be fine ... that was over 20 years ago, though I don't think I got over it until the past 5 years. I don't know most songs unless they are heavy metal or rock and around 20- 30 years old.
     
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  12. robert presti

    robert presti Member Established Member

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    I guess a reality check on that would be songs now 30 -45 years old for the most part.
     
  13. mysticsvt

    mysticsvt southernmustangandford Premium Member Established Member

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    I grew up with 4 uncles so it was Lynard Skynard and AC/DC and everything similar. I like pretty much everything but still listen to some old school rap at times which is what I quoted. Think I am into Country more than anything these days.
     
  14. robert presti

    robert presti Member Established Member

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    I like some country but not much. Rebel Son and the Pine B ox Boys are interesting , though not sure what they are classified as. Banjos and steel guitars are neat even to this metal head. If you're into music check out Spotify.
     
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