Page 4 of 4 FirstFirst 1234
Results 46 to 54 of 54

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

  1. #46
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    I saw the high idle in your other logs as well. Pretty sure it's not the bin, it's the same thing that drove me nuts on a vehicle, even after testing IAC and IAC wiring it still was happening. Replaced the IAC and it went away... month later same thing, different truck, replaced IAC and it went away. This time I tore apart the IAC to find it stripped in middle... Hope that's your issue.

    There's a smooth tool in TunerPro, takes a little practice but works well, way easier to dial in issues and fuel VE tables when smooth.

    You can get a lope with TBI at idle, have to run Open Loop Idle, then some playing with Idle RPM, fuel, spark idle bias etc... rev engine to dry out wet intake, test drive and see how it does when come to idle again. Have to keep the RPM up for cold starts, if you don't get it right it will load up after a couple minutes. Really a lot of work to make an EFI system run wrong and still run right off idle...

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  2. #47
    Fuel Injected! Davis_1377's Avatar
    Join Date
    Feb 2013
    Age
    34
    Posts
    58
    Yea ive heard the IAC are bad about getting stopped up atleast on some vehicles. being stripped would make since why it wouldnt go past 39 steps, with A and B jumped over I could hear it buzzing constantly like it wasnt moving in either direction. When comparing the 2 bins, I see several "Item Not Defined" could I be using the wrong version of XDF? Im using $42-1227747-V5.1

    I will be running your bin as it does really good.

  3. #48
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    Quote Originally Posted by Davis_1377 View Post
    I will be running your bin as it does really good.
    Did you have doubt?

    That is just a starter chip. If you read the thread we linked to earlier you'll find all the changes mentioned on how to start a chip for a built or big cam engine.

    Quote Originally Posted by Davis_1377 View Post
    Yea ive heard the IAC are bad about getting stopped up atleast on some vehicles. being stripped would make since why it wouldnt go past 39 steps, with A and B jumped over I could hear it buzzing constantly like it wasnt moving in either direction.
    Your supposed to hear the buzzing when it seats all the ay and is still being forced there. The one's I had did seat! But still got stuck/stripped in middle?

    Quote Originally Posted by Davis_1377 View Post
    When comparing the 2 bins, I see several "Item Not Defined" could I be using the wrong version of XDF? Im using $42-1227747-V5.1
    When you see that it means there are changes to hex and that hex does not have a Parameter for it. In this case it is the ESC Done and Lean Cruise patch applied. ESC Done stops the forced knock test. DO NOT enable Lean Cruise until you have a near perfect tune!

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  4. #49
    Fuel Injected! Davis_1377's Avatar
    Join Date
    Feb 2013
    Age
    34
    Posts
    58
    I really love the high idle. After finding out I had some weak plugs I guess, I put new ones in. Im idling around 650-700 and it having the sound of a dragster or something but not quite as rough. Sometimes it wants to idle around 800-900. Ive tried alot of things and cant really get my IAC lower then 46 still. If I do diagnostic mode or play with park to drive steps subtracted I can see that the IAC will go to 0 so I know its working properly. Mabe theres something im missing in the bin.

  5. #50
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    Idle with this ECM is a real trick. First you need to know it will always idle higher in Park/Neutral. It will always IDle higher when not fully warmed up. IAC has full control in Drive and even more Closed Loop.

    DO this, drive vehicle after fully warmed up and data reading or recording, when you pull in driveway or? leave it in Drive and look at IAC counts, where are they now? Should be around 10-20. Higher? Turn throttle blade screw in 1/4 turn with key off! Lower? Turn screw out 1/4 turn with key off. Test drive and do it again. Then forget them, they will always change, this is the only time you look at them.

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  6. #51
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    Can also set "IAC - Max RPM hot Pk/N" to 900 to help to high an idle at other then Closed Loop in drive. And "IAC - Max Cold RPM in Kickdown Mode"

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  7. #52
    Fuel Injected! Davis_1377's Avatar
    Join Date
    Feb 2013
    Age
    34
    Posts
    58
    Yea. The first time I tried this it didnt change, it did now it just takes it awhile to figure it out and adjust. I got my IAC down to about 10-20. I turned it 1 round in from the factory setting after I was done, lol! Everytime I start it I think it has to take awhile to relearn? It will go closed loop and still stay at 39 steps for awhile until it starts to drop the IAC, could that be cause my tps?

  8. #53
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    You'll have to check TPS voltage with that big a movement in throttle blades. Should be .54 volts or close, may have to groove out bolt holes.

    "IAC - Position vs Temp"
    This table sets the amount of bypass air vs. coolant temperature, thus controlling idle speed. This function is similar to the “fast idle” function of a carburetor. Control will transfer to the Target Idle RPM table after a set value of engine coolant has been reached.


    IAC position vs coolant temperature (in steps). After the engine starts, the IAC is decayed from the park position to this position, with adjustments.
    These adjustments can include: A/C on, baro, low battery. It is better to set the IAC position vs. coolant values a little on the low side. This allows the rpm to drop below the desired idle speed, to then be 'caught'. Otherwise, it seems as though the idle never drops down to where it should be.
    Drop this entire table by 10 and recheck.

    Also "IAC - Throttle Follower Idle" can be reduced.

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  9. #54
    Fuel Injected! Davis_1377's Avatar
    Join Date
    Feb 2013
    Age
    34
    Posts
    58
    I got thisn done the other day. The IAC still wants to set at 39 until I trick it, I can pull pressure on my shifter without taking it out of park and it thinks it in drive, then the IAC will start to drop. Nothing seems to make the IAC drop after its started at normal temp, this is not a big prob for me tho. Kickdown steps ive heard should be less then the IAC position vs coolant table but its not, Position vs coolant is at 12 and the kickdown is at 25 tho reducing it dont seem to make a difference other then idling higher. how should kickdown be set?

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •