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NEED TUNING HELP

Discussion in 'Engine/Tuning' started by true_blue02, May 14, 2021.

  1. true_blue02

    true_blue02 Member Established Member

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    indiana
    Hi guys I work for Norris Motorsports in Plainfield, IN and we have a customers 2003 mustang cobra in the shop that we had to finish putting back together because of another shop bailed on assembling the car, so in a nutshell the engine was already together and in the car but either way here is the list of what the car has:

    ENGINE, MMR 4.75 long block, stock compression ratio, ported heads, comp cam stg2 blower cams degreed by MMR,

    BLOWER, Kenne Bell 2.8H freshly rebuilt by PSE SUPERCHARGERS, 3.74 pulley, car also has Innovate west balancer w/2lb lower

    AIR INTAKE, JLT High Boost intake w/ SCT BA3000 MAF

    IGNITION, MSD coils and NGK TR6 plugs gapped 32

    FUEL SYSTEM, Lethal Performance return system w/Walbro 465 pumps, pressure set at 42psi, has Ford Racing 80lbs injectors

    EXHAUST, Bassani mid length headers, 2 1/2 bassani x-pipe going to magnaflow mufflers/tails

    CLUTCH/TRANS, spec twin disc clutch and t56 magnum transmission
    Car also has your typical cooling mods to the supercharger system and is also running a 170 degree T Stat.
    So here is our issue with the car on the dyno and about 3-4k RPM the car just goes way rich and starts bucking/backfiring and today on the data log the timing went bonkers all over the place during the issue. No matter where you set the MAF scale it doesn't change car does same thing every time same RPM. Mind you I AM NOT THE TUNER I am the lead tech there and just looking for answers before yanking the factory ECM out and going stand alone. Any help would be appreciated
     

    Attached Files:

  2. true_blue02

    true_blue02 Member Established Member

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    Location:
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    Here is another data log from this morning driving down the road and this is the newest thing it is doing the timing is all over the place and I get into third gear and ease into half throttle then it cuts out and the wideband goes lean. I know that it makes it tough because I am not logging the AFR's. If anyone would like to see the program that is in the car now I would have to email because it won't let me upload the file Thanks Ugh wont let me upload this data log either because of the size so again if anyone would like to see it please ask and I can email
     
  3. cj428mach

    cj428mach Well-Known Member Established Member

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    Throwing a standalone computer at it sounds like just throwing parts/money at it.

    You might reach out to Lasota racing they train people to tune and will tune for shops and help work on time issues.

    The combo looks pretty basic and shouldn't be an issue.
     
    Blkkbgt likes this.
  4. 03' White Snake

    03' White Snake Well-Known Member Established Member

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    That is literally almost the same build as mine, I do not have a MMR motor tho. I also do not tune my own car.

    1st, I would check the computer is set for RETURN STYLE fuel system.
    2nd, I would swap the MSD coils for Factory Motorcraft versions. These cars do not like aftermarket coils for some reason.
    3rd, what fuel are you running, 93? That might be on the edge with 20lbs of boost on 93.
    4th, How much Vacuum is it pulling at idle, sometimes with Cams the boost bypass will not open. You can check by looking at the arm on it at idle, then reving it up and watch the arm to see if it moves. If you are pulling 8-10" of vacuum it should be fine and I would check for a vacuum leak.
     
  5. true_blue02

    true_blue02 Member Established Member

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    Thanks for the reply but to answer cj428mach reply real quick it is funny you say that because the owner is friends with alot of guys that tune these cars and he has sent them the files and they are even stumped but it makes it even harder for them not having the car in front of them as well but to that note I personally own one of these cars that is built the same other than mine has a stiegemeier stage 8 ported/hybrid blower making 18psi on E85 and makes right at 600/600 and was tuned where I work at and we are not just throwing parts at it lol. We was just wondering if anyone has seen this issue before. because have checked for vacuum leaks ect. It just seems to be something going funky with the ECM??? Now to answer 03'whitesnake yes the ECM is setup for return style and 2nd we was thinking the same thing on the coils because we have seem similar problems with the GM cars 3rd it is on pump gas 93 and lastly I have not checked that yet but was on my agenda to do because when I originally built my engine I had comp stg3 cams and was having issues with my bypass valve including high IAT's and I ended up putting the stock cams back into mine and after retuning I gained power with my stock cams so I will check that and let everyone know. Again thanks for reply because any info is helpful
     
  6. 01yellercobra

    01yellercobra AKA slo984now Established Member

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    The bypass won't affect WOT as it should be closed. That's a part throttle thing.

    I believe trying a new MAF was mentioned in another thread. How did that go?
     
  7. true_blue02

    true_blue02 Member Established Member

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    I tried a couple different things I brought in my air intake which is a JLT ram air W/SCT BA3000 because his is the JLT high boost w/ same MAF and mind you his is brand new but we all have gotten bad parts new that's why I brought mine in and got the same result so I brought in my ECM and loaded his cars info/program and it seemed to make a small difference but results in the end was still the same. So for testing we are going to load my software/tune into his ECM and I am going to take it home tonight put it into my car and see what happens? if my car runs fine then I am pulling out my coils to bring Monday and if my car does the exact same thing then we know we have a issue with the ECM. Only other thing if these test don't work is it could be something bad in the harness or internally in the engine IE cams, timing ect.
     
  8. cj428mach

    cj428mach Well-Known Member Established Member

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    I haven't looked at the logs because I ditched SCT a long time ago but the problem is not the ecm, a standalone would just cost $1000's and have you in the same boat.

    You might reach out to @decipha for help, or check out his site www.efidynotuning.com. The guy is a genius and I think kind of gets off on troubleshooting stuff like this.

    Does it do it at the same point in the MAF transfer? or the same RPM? is it doing it at WOT?
     
  9. true_blue02

    true_blue02 Member Established Member

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    I really appreciate all the info that's why I posted on here because of all the knowledge of these cars. It does it right at same RPM and doesn't matter part throttle or WOT. It's odd because when it gets to the commanded STFT it tanks on both banks and AFR goes lean. I'll have to get with decipha and see what he thinks. thanks again
     
  10. decipha

    decipha Well-Known Member Established Member

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    probably wrong injector data in the tune or a none chronological maf value
     
  11. SecondhandSnake

    SecondhandSnake Well-Known Member Established Member

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    What are you guys using to tune it?

    Out of those logs, exactly where are you seeing the problem? And it's really tough to decipher when there's no AFR data. What are you using to log it? You can usually add in an analog channel pretty easily.

    Keep in mind when things start to go haywire, RPM changing rapidly can change load, which can move spark all over the place. It can get real chicken and the egg.

    I don't see anything too crazy in the logs, but I don't know what I'm looking for, and don't have a complete dataset.

    Double check and see if there's anything that correlates to where you're seeing the issue. First up would be MAF counts, then spark tables, and then injector data. All it takes is fat fingering one entry and things can go to trash. For instance I had one issue that would pop up 30sec after cold start, without fail. I saw that it always occurred at a specific voltage, and tracked it down to an incorrect entry in an injector voltage offset table.

    I'm not too far south of you guys. Might be able to help where I can (though I'm sure as hell no decipha.)
     
  12. true_blue02

    true_blue02 Member Established Member

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    Well to give an update I brought his ECM home after we loaded my tune into his and just shut the VATS off and mind you my car runs fine on my ECM/tune. Also we are using HPTuners to tune it. After I got his ECM in my car it does the same thing so it is telling me that his ECM is bad. He ordered a used ECM so I am going to load his VIN into it and have our tuner build a new program and double check everything in the tune and he has also went ahead and ordered new OEM coils that should be here this week but I am bringing my stock ignition coils into work tomorrow to replace the MSD he has also for testing. and lastly secondhandsnake I will keep that in mind for sure any help is greatly appreciated Thanks again all who have posted
     
  13. 01yellercobra

    01yellercobra AKA slo984now Established Member

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    But you said in a previous post that your ECU in his car with his tune acted the same way. To me that sounds like a corrupted tune.
     
  14. true_blue02

    true_blue02 Member Established Member

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    Well we got it figured out and would like to thank everyone for the insight. It ended up being the MSD coils and a bad ECM. car ended up making 680hp/597tq on pump gas 93.
     
    03' White Snake likes this.
  15. 01yellercobra

    01yellercobra AKA slo984now Established Member

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    Glad it's running. That's a beast.
     

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