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Thread: I5 idle problem

  1. #1
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    I5 idle problem

    I am tuning my I5 and was having a great amount of success until i started trying to change the idle around to have better throttle response off the line. The stock program has a idle RPM of around 650 which sucks off the line... i have found a great sweet spot at 725 or so RPM, but i now have a new problem, about 2/3 rds of the time i am braking now when i hit about 20 MPH and 1000 RPM the RPM's just hold around 1000 until i hit 5MPH or so and then they dip down to like 550-625RPMS and surge for a moment until they go back to 725. I have done some reading on the site and it seems like i would want to adjust the throttle cracker to fix this yet i can't find any table like that to adjust for the colorado and i am thinking it is because it is drive by wire and not a throttle cable??? help me fix this as 725 gives the rado a quick response off the line i would like to keep it there
    2005 Chevy Colorado
    4/4 drop
    1.25" thick front and 1" thick rear sway bars
    Nitrous Express wet kit
    billet servo
    JL12W7 in custom ported box w/ Phoenix Gold 1200.1

  2. #2
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    Throttle controls are not available for us Collie guys yet... I have a request in the Feature request section (for this exact reason actually..).. Give it a bump...


  3. #3
    HP Tuners Support
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    Bill@HPTuners's Avatar
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    werd...feature requests is where its at...the more voices are heard the higher it goes on the wish list.
    It doesn't have to be perfect, it just needs to be done in two weeks...

    A wise man once said "google it"

  4. #4
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    then off to feature requests i go.... man i was hoping that wasn;t my answer cause the rado flies off the line with a 725 RPM idle, as soon as i hit the gas even the slightest bit the truck starts to pull like a bat out of he*l
    2005 Chevy Colorado
    4/4 drop
    1.25" thick front and 1" thick rear sway bars
    Nitrous Express wet kit
    billet servo
    JL12W7 in custom ported box w/ Phoenix Gold 1200.1

  5. #5
    HP Tuners Support
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    if its not currently in hptuners a features request is the best way to get it added if its in the code & needed they will try to add it.
    It doesn't have to be perfect, it just needs to be done in two weeks...

    A wise man once said "google it"

  6. #6
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    i was also looking at this last night while doing some reading on other functions and i think i found out what the computer is doing and it may not have anything to do with the throttle controls....

    these trucks do this surging thing from the factory, just not as often as when i changed the idle. i was looking at the DFCO settings and saw that they are set at 1700 RPM, which is right where the surging problems begin when i am decelerating... i was thinking that since i have a ram air setup, along with a True flow filter and cold air intake that maybe when the truck hits DFCO and has all that extra air in there that maybe it is pulling to much fuel and causing the motor to stutter, could this be the cause??? if so would there be any harm in taking off DFCO or at least a way to change how much fuel it is pulling so the motor doesn;t sputter from lack of fuel???
    2005 Chevy Colorado
    4/4 drop
    1.25" thick front and 1" thick rear sway bars
    Nitrous Express wet kit
    billet servo
    JL12W7 in custom ported box w/ Phoenix Gold 1200.1

  7. #7
    Alot of the Ion's do this EXACT same thing....
    2005 Stage 2 Saturn Ion Redline
    260whp, 225wtq 14.0 @ 13.7 (2nd time dragging)

    RedlineForums.com Moderator and Eager Tuning Noob.
    Chicago, IL

  8. #8
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    really??? that is odd... i really think that the DFCO is pulling to much fuel once we are adding free flowing intakes and exhausts because off all the extra air flow that the comuter isn;t registering... how rich do you ION guys run because the I5's run really rich out of the factory... i have already changed one set of spark plugs at about 15k and i am at 21k right now and i have ahd to clean my exhaust tips of that nice black build up about every 7k since i bought the truck
    2005 Chevy Colorado
    4/4 drop
    1.25" thick front and 1" thick rear sway bars
    Nitrous Express wet kit
    billet servo
    JL12W7 in custom ported box w/ Phoenix Gold 1200.1

  9. #9
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    Ya know..I noticed the same thing when I stuck my AEM on... never thought too much about it... makes sense tho... Maybe try setting the DFCO down around 1000 rpms and see what it does?? Might give the VCM time to read the change in airflow before hitting the cut...
    2007 Mustang GT
    266rwhp 276rwftlb's. 13.6@104 stock.
    Adding a bunch of goodies and shooting for mid 12's.

  10. #10
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    i was going to start messing with it tonight or tomrrow, guess we'll find out, but now that you are seeing the same thing i am when i sat down i think it really is DFCO pulling way to much fuel
    2005 Chevy Colorado
    4/4 drop
    1.25" thick front and 1" thick rear sway bars
    Nitrous Express wet kit
    billet servo
    JL12W7 in custom ported box w/ Phoenix Gold 1200.1

  11. #11
    DFCO is Deceleration Fuel Cut Off. It cuts fuel completely if the conditions are met during deceleration.

    Chris...
    I count sheep in hex...

  12. #12
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    so then your saying i would have to turn DFCO all the way off Chris??? or what are you telling me because the current DFCO settings have it come on at 1700 RPM and off at 1400 RPM and that is right where the surgings starts until i come to a complete stop and then it revs back to life.....
    2005 Chevy Colorado
    4/4 drop
    1.25" thick front and 1" thick rear sway bars
    Nitrous Express wet kit
    billet servo
    JL12W7 in custom ported box w/ Phoenix Gold 1200.1

  13. #13
    Супер Модератор EC_Tune's Avatar
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    You may want to look at the spark parameters and the airflow values to enter/exit DFCO. The airflow values will match your spark table airflow values or = the dynamic cylinder air PID.
    Always Support Our Troops!

  14. #14
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    cool...thanks for the imput... i went ahead and disabled DFCO all together and some of the surging is gone but the maing surge, at like 800-700 RPM when it will dip down to 500 or 550 and then back up is still there from time to time, so i will go look at those tables
    2005 Chevy Colorado
    4/4 drop
    1.25" thick front and 1" thick rear sway bars
    Nitrous Express wet kit
    billet servo
    JL12W7 in custom ported box w/ Phoenix Gold 1200.1