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Thread: 0411 ecu on l31 hard to start

  1. #1
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    0411 ecu on l31 hard to start

    hi guys, im looking for some advice here...

    I did a wiring harness for a customer to run a TPI intake on their 3rd gen camaro. I had them set up the engine as an L31 with all of the correct sensors and what not. I have done this previously and it has worked fine.Icant seem to get this engine to start without giving the throttle a little blip and when it does fire it doesnt seem to want to add any ignition timing advance until the rpm is over 500. This causes another issue when you put it in gear, if the rpm dips too low the ignition timing goes back to 0 and the engine dies.

    The engine is a stock crate motor 350
    has low compression, maybe 8.5/1
    Cam in it is a flat tappet cam from an 80s corvette, dont have the specs on it
    Im running this with a 0411 ecu

    I know ive got some goofy stuff going on with the tune right now but that was to get the car to be able to idle and be drivable so they can move it around

    Let me know what you guys think, ill post the tune and a log file of trying to start it.

    Thank you-Tim start up.hplNEW ECU8.hpt

  2. #2
    Tuning Addict blindsquirrel's Avatar
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    Injector data does not look correct. Comparing to a stock '02 Express L31 file, the flow rate has been changed to 32lb but everything else is the same.

    screenshot.25-11-2021 21.43.25.png

  3. #3
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    Sorry I forgot to mention that it has 32lb injectors installed.

  4. #4
    Tuning Addict 5FDP's Avatar
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    Did those injectors come with data, because you are missing the rest of the data in that tune to make it work right.

    Injector flow rate, min injector pulse, short pulse limit/adder and offset vs volts data is all needed when swapping injectors.
    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.

  5. #5
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    They are Bosch injectors. I need to look up the data on them and put it in still. It’s not the fueling I’m worried about though and I don’t think that’s what’s causing it to not fire up when cranking it without opening the throttle some

  6. #6
    Tuning Addict blindsquirrel's Avatar
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    Injector data affects everything else.

    Any particular reason for using a LS base file instead of L31?

  7. #7
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    I’ve had these injectors installed on another engine and just changed the flow rate and they worked fine. The tune was originally a 5.3 but I segment swapped a full 2002 express tune onto it