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Thread: Tuning for Mild Cam, Headers, etc....

  1. #31
    Fuel Injected! Davis_1377's Avatar
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    Im gonna go with a manual trans later but till then.. Turning the screw really helped, I turned it a few more just to get the IAC closer. I moved the timing from 22 to about 24 but most of the data it stays about the sane. Fuel is alot closer too I think, INT drops way down and comes back up. Im gonna move the fuel tables more later after the rain and cold. Here is the datalog just to see. About where should the IAC be setting at a idle?
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  2. #32
    Fuel Injected! Davis_1377's Avatar
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    this cam has similar characteristics to mine just less valve overlap. if your heads and intake can supply the flow this cam is going to demand at 4500 rpm and above you are going to need more fuel and a bigger TB. also 550 is too low of an idle for that cam 750+ is where mine is set to idle at with 24* timing.Thats nice, That would be intersting to hear it.
    That's nice, it be interesting to hear it.

  3. #33
    RIP EagleMark's Avatar
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    You have to judge IAC counts at the end of a drive, then idle. Under 20 counts, 10 is better. But then have to look at TPS voltage, perfect is .54... .65 is OK.

    Somehow your missing idle timing? It's not 22-24. Tell you what, post your bin, I'll do a couple changes for you. You have to learn how to use Compare function and Data tracing. Data tracing is already set up in the $42-1227747 files. Then when you get bin back, open it, load your stock or last bin and use compare to see what I did.


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  4. #34
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    Quote Originally Posted by EagleMark View Post
    You have to judge IAC counts at the end of a drive, then idle. Under 20 counts, 10 is better. But then have to look at TPS voltage, perfect is .54... .65 is OK.

    Somehow your missing idle timing? It's not 22-24. Tell you what, post your bin, I'll do a couple changes for you. You have to learn how to use Compare function and Data tracing. Data tracing is already set up in the $42-1227747 files. Then when you get bin back, open it, load your stock or last bin and use compare to see what I did.
    Probably under estimating how far the idle map is pushing the idle sa area at idle would be my guess.

    The TPS can be slotted and the idle voltage returned back stockish.

  5. #35
    Fuel Injected! Davis_1377's Avatar
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    Somehow I couldnt find idle timing. Compare I can use, data tracing I can figure out. The JET is the bin I was using, this is one I didnt mess up. The ACSF is the stock one, which ever one you prefer. Thanks that will help me alot.
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  6. #36
    RIP EagleMark's Avatar
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    Considering Jet sucks and it's a Ca bin, that's out... ACSF was superseded twice to AMUR which is a good one, So I'll do my favorite... ADSU!

    EDIT: I wanted to see what you were doing so I can help?

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  7. #37
    RIP EagleMark's Avatar
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    Give this a shot and get a data log.

    EDIT: Stock for compare.

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
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  8. #38
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    Quote Originally Posted by EagleMark View Post
    Considering Jet sucks and it's a Ca bin, that's out... ACSF was superseded twice to AMUR which is a good one, So I'll do my favorite... ADSU!

    EDIT: I wanted to see what you were doing so I can help?
    I have compared Federal and CA binary files before and generally CA has a richer O2 target voltage, slightly retarded ignition timing (especially during warmup)and delayed torque converter lockup. Baically looks like they were trying to warmup the cat quicker and reduce NOx emissions. To clean up the extra hydrocarbons they blew air into the manifolds in open loop warmup to help preheat the cat and then diverted it into the cat with a warm engine.
    Last edited by Fast355; 03-31-2013 at 08:15 AM.

  9. #39
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    Back in these old TBI trucks Ca had air pumps too and fed did not. I've also found WAY more Ca bin files superseded then feds. Guess they were never happy and always pushed...

    Ca was always pushing vehicle manufacturers, funny how the state best known for hot rods... killed cars... well they killed themselves too!

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  10. #40
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    That looks pretty good! After I come up and stop it still stays at about 1200rpm and no way to get it back down unless I shut it off and start it back. I tried adjusting the screw again to get my IAC lower but it seems to not want to go under 39 steps.
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    Quote Originally Posted by Davis_1377 View Post
    That looks pretty good! After I come up and stop it still stays at about 1200rpm and no way to get it back down unless I shut it off and start it back. I tried adjusting the screw again to get my IAC lower but it seems to not want to go under 39 steps.
    I have had the high idle issue myself. I am trying to remember how I corrected it. IIRC it had something to do with the IAC logic and having to change some faulty values.

  12. #42
    Fuel Injected! gregs78cam's Avatar
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    Quote Originally Posted by Davis_1377 View Post
    That looks pretty good! After I come up and stop it still stays at about 1200rpm and no way to get it back down unless I shut it off and start it back. I tried adjusting the screw again to get my IAC lower but it seems to not want to go under 39 steps.
    That's funny, I had the same problem with my '7427 in the camaro.....start up, idles good, put in gear and back to P/N and IAC/idle won't come back down, i think mine wouldn't go below 27 steps. I ended up switching to a Big Block bin to start, and all that went away, along with having a better spark map for my application.
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  13. #43
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    Quote Originally Posted by Davis_1377 View Post
    That looks pretty good! After I come up and stop it still stays at about 1200rpm and no way to get it back down unless I shut it off and start it back. I tried adjusting the screw again to get my IAC lower but it seems to not want to go under 39 steps.
    Everytime you adjust the screw you have to have the key off for...? 10 seconds, then turn back on and ECM will calculate 0% TPS position, this is not based on TPS voltage, this is always an issue if someone has foot on gas when starting too. If you change TPS% at throttle closed to other then 0% nothing works right.

    I did make the IAC adjustments for this? What is your elevation? It may be do to Baro adjustment...

    Also could be a faulty IAC, I've done a couple in last year my self that had IAC counts but pintle was not moving. It's a gear drive that wears out/stripped. See if your IAC drives all the way closed by shorting A and B on ALDL port, turn key on, no start, walk around to IAC and unplug it. Start motor and should idle much lower, while not running you can look down IAC port from top of TBI and see pintle seated. Should be no air going through this port with pintle seated.

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  14. #44
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    Quote Originally Posted by gregs78cam View Post
    That's funny, I had the same problem with my '7427 in the camaro.....start up, idles good, put in gear and back to P/N and IAC/idle won't come back down, i think mine wouldn't go below 27 steps. I ended up switching to a Big Block bin to start, and all that went away, along with having a better spark map for my application.
    A lot of times that is do to "IAC - Position vs Temp" I cut them in half is usually enough.

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
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  15. #45
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    Yea i always leave the key off for awhile, I even leave it on for a little before starting it. I had the high idle after going to park problem with other bins too, the only time I didn't have it is when my spark wasn't advanced far, don't kno if that would lead to figuring it out. What do you use to make your spark tables they look nice and smooth. Anyway I can have the cammed lopey sounding idle with this tune also? I aint had much time to do the data tracing and stuff much yet. Im thinking about getting the Ostrich so I can do things more quicker and easier.

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