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Idle problem, Getting "cruise control effect"...

1793 Views 19 Replies 7 Participants Last post by  04CTSVFLA
I think my idle it set too high, it's at 900. I noticed that my car in first gear with no gas will cruise all day long at about 5-7mph. I also noticed that during regular driving, taking the foot off of the accelerator, and the car keeps going like a "cruise control effect". What is the correct idle speed for the "V".

My mods are magnaflow catback w/RT High Flow Cats, Ported TB, and CAI. The last mod i did were the RT High Flow Cats.
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Whoever tuned your PCM needs to adjust your throttle decay or idle speed (or both).

Other possibilities:

-Sticking (dirty) throttle blade
-TPS calibration is off, and it needs a relearn (instructions are in the FAQ)
-Vacuum leak somewhere near the TB.

I'd try the last three before going to your tuner, as they're free.
>Whoever tuned your PCM needs to adjust your throttle decay or idle speed (or both).

I had a local shop just do a basic dyno tune (before the RT cats) useing my HH Predator. I know i can adjust the idle with the HH Predator, but i'm not sure about throttle decay (or even what is is).

BTW.. Would you, or anyone else happen to know what the correct idle speed is.
Before you get too far, check your floor mat and make sure it isn't putting pressure on your accelerator.
> but i'm not sure about throttle decay (or even what is is).

I never heard of it either, but just using common sense, I'm guessing it has to do with the ratio or speed at which your car returns to idle position after letting off the gas pedal. Not sure though. :confused: Even a google search didn't return anything for me.
I just looked through the manual and didn't see a setting for idle speed for the 5.7, although it showed them for the 2.8 and 3.6. I'll go dig through my PCM settings and see if I can find anything in the factory flash settings.
This is the table in my default PCM flash.

Edit- I scrolled over from the -40 setting on the table as it's the same as -19 and showing at the top. 800rpms seems to be the lowest setting out to any outside temp we would be operating in.
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800 is the correct idle RPM for a CTS-V. I don't believe the Predator allows you to get as detailed as more expensive options like EFILive or LS1edit. If your throttle decay isn't set right, it will definitely "cruise control" on you in 1st. Lots of F-Body guys have this problem after cam or LS6 intake installations.

If your shop used you Predator to tune it, I'm guessing it's just idle speed. Don't forget to check for vacuum leaks and try a TB relearn before going too crazy with the tuner. Also, what changed to cause this problem- did it just come out of the blue, or after you did something (changed intake, added cats, whatever)?
I had this problem to a lesser extent after i had my TB ported, most folks around here thought that this was normal for our cars. However, after the installation of the RT High Flow cats it has gotten worst. I can easily adjust the idle down to 800 with the predator, but i am unsure that this will solve it.
I have the same problem and I dont have a tune....
What mods do you have?
Check the connections on your intake box- 99% of fuel trim or idle problems with these cars is an intake leak.
I actually just noticed that my airbox seems to almost be warping from heat possibly, and the top and bottom are starting to seperate from eachother even though the clips are clipped. Also one of my clips appears damaged. Do I have any luck getting that box replaced under warranty? I bought the car as is, with the modified airbox from the should warrant it. For all I know its been like this for a while....possibly causing my engine to breath dirty unfiltered air....this is extremely disappointing.
Man that is crazy! My 04 just started doing that this morning! I got it back form the dealer, reprogrammed the maggie tune, just in case, and all day so far its been idling really hi and it goes back down when i come to a complete stop. I figured it'll go back to normal soon though
Would anyone happen to know of a good "V" tuner in Massachusetts. One that preferably has the advanced Diablosport "Chipmaster Revolution" tuning software. :)
I was serious about the floor mat. Manny a throttle issues have turned out to be nothing more than a floor mat that's slipped up against the accelerator pedal.

I'm not trying to insult anyone intelligence, just trying to eliminate the simple things first.
That was actually a pretty good suggestion S.D. Several owners have reported issues with their floormats affecting the accelerator pedal.
Ok... just checked my front drivers floor mat, and that is not the problem (i wish it was).
advanced Diablosport
.......AHAHAHAHA....those two words should never be side by side, sorry. diablosports programming almost was responsible for blowing up my ls6 in my V. Shits weak and sucks ass.
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