Idle drops into the 400's when AC compressor kicks on

Discussion in 'Engine & Performance' started by Denaliano, May 1, 2009.

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  1. Denaliano

    Denaliano Resident Guinea Wop

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    Perhaps unrelated, but ever since I've had my BB tuned PCM in, i've noticed a considerable dip in my idle speed at a light, stop signs, anytime i'm idling in gear, with the brake applied.

    Looking at my efilive log files i see a steady 540-560RPM idle, but when the AC compressor kicks on, it will drop to the low to mid 400's causing a brief but noticeable stumble. bbbbbbbbbbbbbb..buuuhblaaaaah...bbbbbbbbbbbbbb :jester:

    For why?
     
  2. Toadster

    Toadster did you sharteeze today?

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    omg - can't you search?
     
  3. StanfordM_3

    StanfordM_3 GMFS Member

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    :slap:
     
  4. Denaliano

    Denaliano Resident Guinea Wop

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    Bump for ideas :kiss:
     
  5. thunder550

    thunder550 GMFS Member

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    Sounds like either your idle RPM table or idle airflow table needs some work.
     
  6. Hit Man X

    Hit Man X HOT AIR BALLOON OWNER

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    Easy fix.
     
  7. HD Redneck

    HD Redneck GMFS MoPar/Air Force Crew

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    :lol:
     
  8. nick993

    nick993 LAID OUT TIRE FRYER

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    unhook your battery, then hook it back up after a while. then start the truck and let it learn for a few minutes(it will be rough then start to idle better). then kick the a/c on and it will bog but dont give it gas, just let it learn. it worked for me. the last time i unhooked my battery, i just hooked it up and took off, forgot to let it learn and it started dying on me at lights.
     
  9. Matt

    Matt Guest

    Sounds like you got a cam in there, bro...wanna race?

    I've read about solutions similar to Nick's. I'd give that a shot. Otherwise you can leave the severed head of a horse in Justin's bed.
     
  10. nboylie

    nboylie GMFS Sr. Canadian Member

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    Pull out that johnson rod and give it a good clean with some brake cleaner, re insert and lube up.
     
  11. Parke10

    Parke10 PT.Net Member

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    i find myself staring at yer avatar for like 5 mins everytime i read one of yer posts.... :think:
     
  12. Denaliano

    Denaliano Resident Guinea Wop

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    I don't understand the learn part.

    This is a freshly tuned PCM, it should of already learned by now, I'm over 50 ign cycles.

    I should have to clear anything out :think:
     
  13. 86mcss

    86mcss HUNTING

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    It sounds like you need to change your adaptive idle air flow while a/c is on...if you need help let me know. I can guide you through it.
     
  14. 02White6.0

    02White6.0 GMFS Member

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    Not sure if you can do this in EFIlive, but in HPT most users do a crank relearn after tuning which helps the vcm learn the new tune.
     
  15. Denaliano

    Denaliano Resident Guinea Wop

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    lemme try that, EFILive has a CASE learn function
     
  16. theholycow

    theholycow AllOffTopic.com FTW!

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    Blackbear's site says you need to do a crank relearn after a tune...
     
  17. Denaliano

    Denaliano Resident Guinea Wop

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    This was a live, on site, in Albany, New York, in person tune.

    Not a mail order.

    I would have expected Justin to have performed that after he completed the tune on my truck. In person.
     
  18. HD Redneck

    HD Redneck GMFS MoPar/Air Force Crew

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    Did you check out Justin's engine? Sick :drool:
     
  19. Denaliano

    Denaliano Resident Guinea Wop

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    It was filthy like the engine bay of a Donk and he told me not to mind the rats nest of wires in the drivers side of his firewall.

    :blah:

    [​IMG]


    :crazy:
     
  20. Ginger

    Ginger kissin hands shakin babie

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    true

    and mine stumbles in park.
     

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