Idle speed too high until car is FULLY stopped?
05-21-2003, 11:31 PM
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Idle speed too high until car is FULLY stopped? Anyone know which parameter nails this pest down?
I'm running a 242/242 Comp Cam and the idle and drivability are near to stock EXCEPT...when fully warm the idle will stay at 1400 RPM until the MPH is zero and then it falls to 950..
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05-22-2003, 07:53 AM
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Re: Idle speed too high until car is FULLY stopped? I have just noticed my car doing this, but not so high. It'll sit at about 1100 and then drop to 900. No idea where to fix it though. Seems I remember reading somethign about it in the ls1edit mailing list.
05-22-2003, 04:56 PM
#3
Re: Idle speed too high until car is FULLY stopped? That's a built in feature of the PCM intended to decrease emissions and keep the rpms up to run accesories like the power steering at speed. Not sure how to disable this, but I heard a while back it could be done with LS1edit . . . anybody know how?
05-22-2003, 05:00 PM
#4
!Dial-up Director
Re: Idle speed too high until car is FULLY stopped? Mine does the same thing, will go to 1200 when I let off the gas then settle to 900 when I stop for a sec. It's aggrevating.
Justin
Justin
05-22-2003, 05:02 PM
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Re: Idle speed too high until car is FULLY stopped? You need to adjust "RA-Running Airflow" Here is the LS1Edit.com link for the thread. Running Airflow Good Luck. Let us know how it turns out Guys! 
joel (Bink)
Ooops- I had the wrong thread- I corrected it.
joel (Bink)
Ooops- I had the wrong thread- I corrected it.
05-22-2003, 10:16 PM
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Re: Idle speed too high until car is FULLY stopped? I'm getting closer - the drop in RPM is now from 1100 and almost instantaneously from 5 MPH or less. Moved the running idle air around and moved up the decay vs MPH by 25%.
Is your idle ~950 RPM? What's the LSA on that bigboy? I'll bet it sounds Beautiful! Trending Topics
05-23-2003, 10:56 AM
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Re: Idle speed too high until car is FULLY stopped? Under IDLE & LIMITERS
Go to THROTTLE FOLLOWERS
There are 3 DECAY tables.
I think you have to mod those tables; I have never done it...
But the DECAY is the rate of delay that the RPM used when releasing your foot from the gas pedal under certain situations...
Good luck.
Tommy
Go to THROTTLE FOLLOWERS
There are 3 DECAY tables.
I think you have to mod those tables; I have never done it...
But the DECAY is the rate of delay that the RPM used when releasing your foot from the gas pedal under certain situations...
Good luck.
Tommy
05-23-2003, 07:16 PM
#10
Re: Idle speed too high until car is FULLY stopped? Awesome info. I have the same issue. Ported TB. Car's been fine, until I tried a PCV redo. After I did that, the high idles at a light ( 2K )started along with difficulty stopping. Naturally I looked for a vacuum leak, and even went back to the original PCV setup. Reset computer. Disconnected battery for an hour. Not much improvement. THIS will help, along with the reference to the LS1Edit mailing list.
Will a vacuum leak exhibit the same behavior?
Will a vacuum leak exhibit the same behavior?
05-27-2003, 04:41 PM
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Re: Idle speed too high until car is FULLY stopped? TTT
I have the exact same problem as Viper. I put in the LS6 PCV System and suddenly when I'm driving down the road and put the car in neutral or stop at a light and push in the clutch, my car just sits at almost 2000 RPM. It takes like 6 seconds after I stop to go down to 800. It is really making me mad. What is the problem and how do I fix it?
I have the exact same problem as Viper. I put in the LS6 PCV System and suddenly when I'm driving down the road and put the car in neutral or stop at a light and push in the clutch, my car just sits at almost 2000 RPM. It takes like 6 seconds after I stop to go down to 800. It is really making me mad. What is the problem and how do I fix it?
05-28-2003, 12:24 AM
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Re: Idle speed too high until car is FULLY stopped? How do you tell if there is a vaccuum leak for sure and how do you find where it is? I had to remove the intake manifold when I changed the PCV and it may be coming from there because when I put it back on, it didn't want to sit right because of a coolant line. How do you tell where the vaccuum leak is??
05-28-2003, 02:21 PM
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Re: Idle speed too high until car is FULLY stopped? I had the same problem with the rpms staying at 2g's when comming to a stop and then slowly comming down when i put a ported throttle body on, but when I put the stock TB on the car it idles and drives just fine, the ported throttle body was also put on another car and it acted the same way, but went back to stock fine, what could be the problem here?
05-29-2003, 06:38 AM
#17
Re: Idle speed too high until car is FULLY stopped? From what I've read:
Either the hole is too big in the TB to idle correctly
Or the blade is not sealing 100% to the TB itself
Or the little motor attached to the TB ( don't know the name ) could have gone bad
Or finally the bumpstop is not reading 0.00 when you're foot is off the gas. ATAP may show .04 to .08.
Maybe this will help. My car is getting a new exhaust ( Stainless Works, our new Exhaust Sponser ) so I can't test these ideas till I get it back.
Either the hole is too big in the TB to idle correctly
Or the blade is not sealing 100% to the TB itself
Or the little motor attached to the TB ( don't know the name ) could have gone bad
Or finally the bumpstop is not reading 0.00 when you're foot is off the gas. ATAP may show .04 to .08.
Maybe this will help. My car is getting a new exhaust ( Stainless Works, our new Exhaust Sponser ) so I can't test these ideas till I get it back.
08-27-2004, 04:07 PM
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I have the same problem, car idles around 1200rpms with no gas input till I comletely stop, then it`s back to normal. I`ve had the same hole drilled in the TB for a few years, this just started recently.
You guys ever figure it out?
You guys ever figure it out?
08-28-2004, 07:29 AM
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maybe your iac is just clogged up with crap or dying?
isn't there a 2/3mph idle cracker setting? i set mine to 1/2 once and it was very odd on how the car behaved when backing up.
isn't there a 2/3mph idle cracker setting? i set mine to 1/2 once and it was very odd on how the car behaved when backing up.
