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Thread: E38 LSA swap No Start

  1. #1
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    E38 LSA swap No Start

    Hello,

    I have a LSA swapped 6.0 with a stand alone E38 harness in a 78 Trans Am. It has the 3 Bar Map (PN:12592525) and the LS7 MAF (PN:15865791). It has FIC 95LB injectors with Aeromotive fuel pump and boost referenced regulator. I have scaled the injecters doing the half IFR/IVT and double Stoich. I halved the MAF and adjusted the main spark airmass table. VATS and Starter Diagnostics are disabled. It has an oil pressure sensor.

    I can not get it to run. It will crank, sound like its going to start, and then die. About every other try, it will pop through the exhaust. I have checked coil packs and injectors. I found the driver's side injectors were wired "backwards" and fixed that, but no change. The stock tune on the ECM is from a G8. At this point I took a stock LSA tune and started copying Airflow and spark tables over to try to get it to run and still nothing.

    What's even more, I had it running NA before the LSA swap. We had it setup with a fast intake and I had it idle for about 5 minutes before we had some issues with the gauges (thats with the drivers side injectors "backwards" also). As we were fixing the gauge wiring, we put the LSA blower on and now I cant get it to run at all.

    I fully intend on taking it to a professional to get tuned. I just need to be able to get it running and have it be able to move under its own power. I have some experience tuning some GTP's awhile back, but nothing like this. I am not sre what to do next.

    Sorry for the long winded explanation. Any Help would be appreciated.

    Build specs:
    Gen IV 6.0
    Texas speed rods/pistons
    GM 58x factory crank
    PRC ported heads
    Brute Speed EPP cam Specs - Dur @ .050 232 int 240 exh - Lift .595 int .608 exh - Lobe Sep 115.0
    Stock LSA Blower with 2.38 Pulley (12psi with ATI crank pulley)
    Kong Performance Lid
    NW 102
    T56 Magnum
    Attached Files Attached Files

  2. #2
    Do you have your injector data?

  3. #3
    Tuner in Training
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    Check and let me know please
    Attached Files Attached Files

  4. #4
    Senior Tuner
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    The injector data is stock. You'll need the proper characterization data in order to get it going.

  5. #5
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    Got the injector data from FIC today. I will update tonight. Thank you!

  6. #6
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    Got it to run this morning with the correct data. Thank you! How did it possibly run the first time around with the wrong data and one bank of injectors backwards?

  7. #7
    Did you start it with the 95lb injectors?

  8. #8
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    Quote Originally Posted by Mr.z0611 View Post
    Did you start it with the 95lb injectors?
    Yes, these are the only injectors we have had.

  9. #9
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    I got the correct injector data and got it to start, run, idle. It takes two or three tries to get it started and when it does start, it pops through the exhaust a bunch while its cranking before it actually starts to idle. Any suggestions?

  10. #10
    Tuning Addict blindsquirrel's Avatar
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    Suggestion? Log file of what it's doing in its current state.

    Have you verified the harness has the cam sensor pinned correctly?

  11. #11
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    Quote Originally Posted by tshansen View Post
    I got the correct injector data and got it to start, run, idle. It takes two or three tries to get it started and when it does start, it pops through the exhaust a bunch while its cranking before it actually starts to idle. Any suggestions?
    Typically a cam sensor problem. Do you have any DTC's?

  12. #12
    Senior Tuner Frost's Avatar
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    Quote Originally Posted by tshansen View Post
    Hello,

    .....I have scaled the injecters doing the half IFR/IVT and double Stoich. I halved the MAF and adjusted the main spark airmass table.

    If you went the IFR/Stoich table method you should NOT have scaled the MAF and spark tables... you are mixing methods. If you are going 1/2*IFR and 2*Stoich, put the OEM MAF table and spark arrangements back (and ANY other changes other than the IVT stuff). Having the MAF cut in half sure won't help cranking or idle.

    As others noted, the pops/issue during cranking is likely cam sensor related.
    Steve Williams
    TunedbyFrost.com


  13. #13
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    Quote Originally Posted by Frost View Post
    If you went the IFR/Stoich table method you should NOT have scaled the MAF and spark tables... you are mixing methods. If you are going 1/2*IFR and 2*Stoich, put the OEM MAF table and spark arrangements back (and ANY other changes other than the IVT stuff). Having the MAF cut in half sure won't help cranking or idle.

    As others noted, the pops/issue during cranking is likely cam sensor related.
    That was it! Went back to original tune minus injector data and IFR/stoich scaling and no more popping and starts up a lot easier. Cam sensor and wiring both checked out good. Thanks!