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Thread: Low RPM/kPa stalling

  1. #1
    Tuner in Training
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    Aug 2009
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    Low RPM/kPa stalling

    The car was initially remote tuned by a shop but I had some engine issues and he declined further tuning when they were fixed...sucks but I don't blame him. I took it to a local shop to have them street and dyno tune. The car makes very good power, but the streetability is horrible. Its gutless until you lean on it. Backing it out of my garage, it constantly stalls unless you give it tons of RPM. Hot starts are embarrassing as it won't start, then after some coaxing, it coughs to life. Things it didn't do when I gave it to the shop! LTFTs are off, which I thought was weird and there are tons of other changes from the first guys tune also. After some more online help, raising boost enrichment from 48 to 110kPa has made a big difference. Id like to get the lower RPM figured out, I just hope I don't have to start over.

    I've included the local shops tune and a recent log
    Attached Files Attached Files

  2. #2
    Tuning Addict blindsquirrel's Avatar
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    Can you give a more detailed description of what it is? 'The car' doesn't really help all that much.

  3. #3
    Tuner in Training
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    Its a 427 with 64/69 turbos, low ram w/intake intercooler, 1000cc injectors, dual pumps, mild cam with a manual trans.

  4. #4
    Tuning Addict blindsquirrel's Avatar
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    And all that with 42lb injectors, or else the tune's been airflow scaled, which is really specialized and hard to figure out everything that was done (and if it was all done correctly) because everybody has their own way of doing it.

    I mean I see stuff like, there's no MAF, but the MAF isn't failed (also no MAF codes in the log). I don't know how to look at things like that and decide if the person who did it was a moron or a genius who found that One Weird Trick...

  5. #5
    Advanced Tuner
    Join Date
    Jan 2015
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    565
    Looks to be scale at the ve table by half or possibly more. The cyl airmass at boost is only in the low .60 range. I would start with a fresh tune with a custom os and rescale your injectors properly. You have room for 127lb/hr injector data so it shouldn't be an issue. After that it should come in line fairly easy.