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Thread: 03 Tahoe new cam and header what to change in the tune?

  1. #1
    Tuner in Training LM7S104X4's Avatar
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    03 Tahoe new cam and header what to change in the tune?

    as title says what should i be modifying in the tune? i just cut the heads (862) .030, installed a TSP 220/220 .600 cam, lunati dual valve spring kit and shorty headers. ive got the truck to idle but its still seems a bit sluggish. i dont have a wideband yet so not tuning the VE table as of now. ive checked the tune repository and there isnt many reliable tunes available for reference.
    thanks in advance!!!!

  2. #2
    Tuner in Training LM7S104X4's Avatar
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    added tune and datatlog
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  3. #3
    Tuner EWY's Avatar
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    Set the tune to openloop. Increase the base airflow, adjust the timing at idle. You can get more done once you install the wideband.

  4. #4
    Tuner in Training LM7S104X4's Avatar
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    i ran another datalog and appears im getting some wicked misfires at idle. not sure whats going on at the moment. i did fresh set of iridium plus and wire and have insulators on th eboots to prtect them from the header heat.

  5. #5
    Tuner in Training LM7S104X4's Avatar
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    ok ive switched to open loop but left stft on in open loop, added some idle rpm and a bit of air at idle. its still showing random misfires. how much and in which direction should i be adjusting the timing at idle? thank you for your help.

  6. #6
    Tuner in Training LM7S104X4's Avatar
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    all the sudden its going into reduced engine power each time i write calibration with a po1518. if i clear the dtc it goes away and stays away unless i write a new tune. not sure why

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  8. #8
    Tuner in Training LM7S104X4's Avatar
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    could really use some direction here fellas. the truck is now stalling while driving after throttle is released. this is new and tune has not changed. im lost

  9. #9
    Gonna give a basic answer, best I got at the moment. Is the throttle body clean? Min closed airflow affects alot, and if learned wrong it will fubar things. Does scanner have the idle learn reset?

    Hope you get it sorted.
    03 Z06 stock.......for now
    05 Siearra 5.3 daily
    I have realized that tuning is a rabbit hole. No problem diving down this hole, in fact I jumped willingly. Just want to avoid hitting every ugly rock or root on the way down it.

  10. #10
    Tuner in Training LM7S104X4's Avatar
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    throttle body is very clean, i have the ETB and it hasnt been touched physically or in the tune. i got the stall issue resolved but not it seems it has a hanging idle and wont coast.
    ill do a log and post shortly. thanks for any help guys i need to get this figured out and get this thing running properly.
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  11. #11
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    Here ya go. Try this and see how it performs.
    2003 Taho MOD 4 camkwmod.hpt

  12. #12
    Tuner in Training LM7S104X4's Avatar
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    awesome ill give it a shot now! here is a datalog from a drive a few mins ago. it seemed ok then stalled again randomly.
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  13. #13
    Tuner in Training LM7S104X4's Avatar
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    Ran so much better according to my butt dyno,(it is at 61% alcohol as i filled it with e85 fyi) it still wont kick down to idle when i left off the throttle. it seems to want to high idle when coasting, my economy gauge was always able to spike up to 70-99mpg when i let off down hills and such now it hangs at 25mpg and i seem to have to hold it back at red lights and when i stop its like your foot is still on the throttle a little when it down shifts coming to a stop......but ran allot better and did not stall.....i did blow a trans line pulling into my neighborhood though so that sucks..
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    Last edited by LM7S104X4; 02-26-2020 at 10:16 PM.

  14. #14
    Tuner in Training LM7S104X4's Avatar
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    ill have the wideband and tranny line in tomorrow, then i suppose i can get down to fine tuning the VE. appreciate the help im still learning but taking it slow

  15. #15
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    Here you go. This will fix the automatic cruise control.

    2003 Taho MOD 5 camkwmod.hpt

    Make sure your TB is clean and not loaded with carbon...
    That can cause some idle issues such as what you're having.

  16. #16
    Tuner in Training LM7S104X4's Avatar
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    TB is very clean. still having that auto cruise issue. also got a dtc for knock sensor bank 1 circuit low, and its pulling allot of timing after this tune. ill post the data log. seems if i get in the throttle more than 50% (PE) its pulling the full 8*. not sure why that would come up all the sudden or if it running 61% e85.

    I do greatly appreciate your help.
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  17. #17
    You said you have ETB, I decipher that as Electronic Throttle Body. Please correct me if I am wrong. If this is DBW/ETB, you should log your accelerator position sensor as well, make sure it is not sticking when you let off.

    I am new at this. This is a shot in the dark, so I hope Kevin can chime in here. Throttle cracker is supposed to be for DBC/IAC controls right? Shouldn't that be zero on the airflow table? Not sure of the effects of zeroing the table out, or maybe just set enable to 250mph so it never comes on.

    Knock sensors are a common issue on this engine family. Mostly plagues 5.3L. If one tests bad, I replace both, the sub harness, and make a silicone dam in a V shape to divert water away from the rear KS hole. Water/liquids collect there. Just talked to someone about this the other day.
    03 Z06 stock.......for now
    05 Siearra 5.3 daily
    I have realized that tuning is a rabbit hole. No problem diving down this hole, in fact I jumped willingly. Just want to avoid hitting every ugly rock or root on the way down it.

  18. #18
    Tuner in Training LM7S104X4's Avatar
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    fixed the knock sensors, got the windband installed and logging. been working on the ve tables and have it running pretty dam good now if i can only solve the engine from wanting to stall while coming to a stop. once stopped the engine will idle fine most of the time but will sometimes want to stall or will increas the idle (tps goes up a few % then after a few seconds will go back to normal) for a couple seconds after stoping. its wiered. ive checked everything and have tried making some changes. the tune is set up for ve tuning (maf disabled, lt and st trims disabled) runs much much better this way for sure. not sure what else it could be. can you guys help me out im stumped and need to get this dialed in.

  19. #19
    Tuner in Training LM7S104X4's Avatar
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    current tune and im happy with it for a start i will dial the trans and ve table more but need to solve this coming to a stop stall and random idle up while stoped in gear on the brake issue.
    please help i appreciate it very much.
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  20. #20
    Is there something in the IAC controls for a transition you could tweak? SFrom the log, it looks like when it tries to die, then it catches itself and idle surges up and down a tiny bit?. That an accurate picture of what it is doing? You don't have your APP logged, so I can't tell if you are pressing pedal to keep it from stalling.

    I haven't gotten into idle tuning. just barely started VE tuning. I may be off base, but worth taking a look at. On your VE table, there is a bit of a dip around 53kpa/500 rpm, then it rises again. Any WB changes that stick out? Maybe try rolling idle at 0 and 10 mph set to 800 or something close.

    These are guesses for the record.
    03 Z06 stock.......for now
    05 Siearra 5.3 daily
    I have realized that tuning is a rabbit hole. No problem diving down this hole, in fact I jumped willingly. Just want to avoid hitting every ugly rock or root on the way down it.