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Thread: Using VCM Scanner with MVPI Pro to scan sensor issues, vacuum issues on 04 Silverado

  1. #1
    Tuner in Training
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    Using VCM Scanner with MVPI Pro to scan sensor issues, vacuum issues on 04 Silverado

    Short: Is it possible to use the VCM Scanner with MVPI Pro to diagnose sensor issues and/or vacuum issues on 2004 Silverado 6.0L?

    Long: I swapped 2004 Silverado 6.0L(LQ4) into another vehicle. It ran reasonable until I did a cam swap. Many issues were encountered during the process After 'walking away' for a bit, I'm back on it. One issue found and partially resolved is the stock injectors stuck. I replaced them with Delphi injectors that were advertised as 'superseded' part number. Turns out they are 8.1L injectors. I had a mail order tune made for the cam and it ran SUPER rich. The tuner adjusted for the 8.1L. It is still running super rich. It has no power. I can mash the gas while driving at 2k rpm and not get thrown back in the seat. I get a sporadic P0200 code but it pops up rarely.

    Before I declare a junk tune issue, I would like to determine if there are any other issues such as sensors 'stuck' and/or vacuum leaks. I would hope that a vacuum leak bad enough to run super rich would show on the MAP.

    Any thoughts?

  2. #2
    Tuning Addict 5FDP's Avatar
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    Post the tune and logs if you want us to look at them.

    Make sure you are running the proper fuel pressure too, should be 58psi.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

  3. #3
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    Quote Originally Posted by 5FDP View Post
    Post the tune and logs if you want us to look at them.

    Make sure you are running the proper fuel pressure too, should be 58psi.
    I'm working on some logs. I am waiting for wideband to get added in(AEM 30-4110)

    I will work on the tune also. I'm not ruling the tune out but I'm hoping it isn't THAT bad.

    I have checked fuel pressure and it was within spec. I'm using a factory 99 Camaro fuel pump/sending unit.

  4. #4
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    I've attached the tune that I'm currently running. I made only one adjustment from how it arrived(pulled fans off)

    The cam is a fairly mild cam. It is a Tick Performance towMAX Stage 1:
    https://www.tickperformance.com/tick...4-lq9-engines/
    208/216 | .561"/.561" | LSA113+4

    I'm not expecting the mail tune to be perfect and was expected to do some fine tuning by scanning/adjusting.

    Aside from the cam, the valve springs and injectors are not stock. The intake is a 'cold air' hot air intake(ie straight pipe pulling from engine bay)
    Attached Files Attached Files

  5. #5
    Tuner in Training
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    I did an install of an Aem 30-4110 wide band and the results are of no help. It is reading so lean it can't display it. HP Tuner raw read show 4.15v to 4.25v which confirms this super lean reading. However, the nose test says this is bull as my eyes water if I huff too long

    So with that, I've uploaded a log. I'm not 100% that it is tuned for the 8.1L injectors(the tune I uploaded) or the 6.0L injectors(old tune) But from a drivability standpoint, nothing changed between the two tunes.
    Attached Files Attached Files