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Thread: wit's end- simple 4.8/ss2 cam/ stock injectors pop off but no idle

  1. #1
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    wit's end- simple 4.8/ss2 cam/ stock injectors pop off but no idle

    I have worked with Cosworth Pectels but have no experience with HPTuners. Despite it's wonky UI and fully-user liable understanding of how and why tables work together, I'm simply trying to get a mostly-stock truck to idle.

    2007 LR4
    SS2 cam
    stock flex 903 injectors @58psi (have used 33@50, 36@58, 33@58 based on conflicting info)
    gen 4 style intake
    DBC throttle body adapted

    Wiring is 100% good and as stock, new Delco OEM crank sensor, all circuits tested. Grounds all under 4ohms.48 ss2 stock injectors 2bar 80e.hptruntest.hplruntestconfig.Channels.xml48 ss2 stock injectors 2bar 80e.hptruntest.hplruntestconfig.Channels.xml

    Using 2bar OS w/ 3 bar scaled sensor. Stock injector data.

    Truck refuses to do more than blurble for a second and die. Typically commands 6:1 AFR on cranking. I've followed all writeups on cam idling, SD failing, etc etc. What the hell is going on? Changing VE table values rarely makes a difference, unplugged MAP/CAM does nothing, 02s in or out nothing. I tried new IACs and TPS sensors. No vac leaks.


    Time for a Terminator and Tuners in the garbage can?
    If I use a stock P01 even with a flex enabled 125 OS and a 1 bar sensor, absolutely no difference.

  2. #2
    Tuning Addict 5FDP's Avatar
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    You don't have nearly enough fuel in the VE table for those stock injectors. Look at a stock VE table and paste that back in for the 15-105kpa section. There is no reason to scale the VE when you don't have the injector to do so with.

    What is the MAP sensor you are using? Your KPA readings are like 103-104 when with key on engine off. The data may be wrong for the sensor.

    Don't put the open loop EQ ratio at 1.00 for every cell either. With no fuel in the VE and no enrichment at colder temps there is no fuel for it to want to run on.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
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    fuck.hpltruck 5-19.hptfuck.hpltruck 5-19.hpt

    using stock lr4 ve settings and only changed injector settings

    truck only will fire and idle when iac unplugged. Iac ohms out just fine. Resetting IAC does nothing.

    Truck commands 14.7 but Ecotrons LSU ADV shows .73 lambda. WTF?
    What is going on? I am about ready to just buy a Link for this setup.

  4. #4
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    Also, put a stock 1 bar map sensor in and adjusted for the settings.

    Added stock VE
    Added stock EQ data

  5. #5
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    Any thoughts before Holley gets one more customer?

  6. #6
    Tuning Addict 5FDP's Avatar
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    I'd probably start over with a 4.8 file and do what is needed to make it run. You should be able to find a stock 4.8 file with a matching OS, then use the segment swap feature to copy over all the 4.8 data in there. Change the injector stuff, put it in speed density, add some base running airflow and see what happens.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  7. #7
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    Did just that right now and it wont even idle for a second, only pops off. It's either the reluctor or the pcm, both point toward Terminator. At least the terminator can indicate there's a crank and cam issue via led, I can't get the stock ecu to report a fault even after many consistent attempts at starting-- 0 rpm signals half the time.

  8. #8
    Tuning Addict 5FDP's Avatar
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    Have you even done a write entire back to the stock OS so it's no longer on the 2 bar OS?

    By all means go Terminator if you want, plenty of us don't have issues with stock computers. Something wiring related or how you'd setup the vehicle/tune is usually the cause for no starts.

    It's running in the one log but it's not showing the P0103 code for a failed MAF, hard to say why that is.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  9. #9
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    I have done this once more, still refuses to start unless the iac is unplugged and then is running .75 lambda when controller is seeking 14.0. Not routinely failing the maf, either.

    Why does the controller not read/output spark once it has fired once and then won't refire?

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  11. #11
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    changed engine because I was convinced it was a crank trigger issue, no difference. Forced LTFT and closed loop off and it does this odd idle surge.

    any ideas?6-22.hpltruckcuck.hpt

  12. #12
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