Idle stumbles when coming to a stop, then recovers
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Idle stumbles when coming to a stop, then recovers
We installed a 224/224 112LSA cam in my car a couple weeks ago. It idles fine, and drives fine, but when I let off the gas to stop, the idle drops to 375-450rpm, then idles back up to where it should be. I don't really want to drill the TB. Is there another option to correct this? The rest of my mods are in my sig
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Re: Idle stumbles when coming to a stop, then recovers
If I increase the RPM, won't it require more air thus amplifying the problem? Is there a way with LS1 Edit to correct this?
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Re: Idle stumbles when coming to a stop, then recovers
Im having the same problem. Mine is even worse. My car dies when i come to a stop. I have to heel and toe every traffic light which is annoying. I would like to know an answer for the same question other than drilling the TB. Would raising 50RPM helps in recover the car from dying? The RPM just go under 800RPM very easy if i didnt give it gas and stalls.
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Re: Idle stumbles when coming to a stop, then recovers
What you guys need to do is increase the values in the Airflow Decay table. I recomend changing all the table values from 0 to 14 mph to 31. This problem is caused by the PCM over compensating; for those that understand control systems, it means the gain is too high causing overshoot. It's like someone learning to drive that moves the steering wheel too much and weaves all over the road.
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Re: Idle stumbles when coming to a stop, then recovers
What you guys need to do is increase the values in the Airflow Decay table. I recomend changing all the table values from 0 to 14 mph to 31. This problem is caused by the PCM over compensating; for those that understand control systems, it means the gain is too high causing overshoot. It's like someone learning to drive that moves the steering wheel too much and weaves all over the road.
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Re: Idle stumbles when coming to a stop, then recovers
Cal:
All the values are less than 1.00 but you suggest using 31.9?
Are you suggesting that he modify all 3 tables?
All the values are less than 1.00 but you suggest using 31.9?
Are you suggesting that he modify all 3 tables?
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Re: Idle stumbles when coming to a stop, then recovers
What you guys need to do is increase the values in the Airflow Decay table. I recomend changing all the table values from 0 to 14 mph to 31. This problem is caused by the PCM over compensating; for those that understand control systems, it means the gain is too high causing overshoot. It's like someone learning to drive that moves the steering wheel too much and weaves all over the road.
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Re: Idle stumbles when coming to a stop, then recovers
If I increase the RPM, won't it require more air thus amplifying the problem? Is there a way with LS1 Edit to correct this?
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Re: Idle stumbles when coming to a stop, then recovers
Drilling the TB is the only real way to make sure the engine gets enough air, other than turning the TB stock screw which is very touchy.
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Re: Idle stumbles when coming to a stop, then recovers
Increasing the timing by 3 or 4 degrees in my car made the drivability worse. It caused the idle to hang and made the surgeing worse. I also think that it made the stumbling when coming to a stop worse slightly it seems like.
Another thing that drives me nuts is I can't get the car to start and stay running without me pushing the gas pedal a little bit. After a few seconds, it will idle.
Another thing that drives me nuts is I can't get the car to start and stay running without me pushing the gas pedal a little bit. After a few seconds, it will idle.
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Re: Idle stumbles when coming to a stop, then recovers
I have the same problem jorday. I've started drilling my TB little by little and it's gotten progressively better each time. One more size and I should be there.
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Re: Idle stumbles when coming to a stop, then recovers
I have the same problem jorday. I've started drilling my TB little by little and it's gotten progressively better each time. One more size and I should be there.
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Re: Idle stumbles when coming to a stop, then recovers
It's pretty easy to do, except that the damn screw is not to access. It has the advantage of being easily reversed, unlike drilling the TB. Unfortunately I learned the hard way about over drilling the TB hole.
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Re: Idle stumbles when coming to a stop, then recovers
I have the same problem jorday. I've started drilling my TB little by little and it's gotten progressively better each time. One more size and I should be there.
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Re: Idle stumbles when coming to a stop, then recovers
Increasing the timing by 3 or 4 degrees in my car made the drivability worse. It caused the idle to hang and made the surgeing worse. I also think that it made the stumbling when coming to a stop worse slightly it seems like.
Another thing that drives me nuts is I can't get the car to start and stay running without me pushing the gas pedal a little bit. After a few seconds, it will idle.
Another thing that drives me nuts is I can't get the car to start and stay running without me pushing the gas pedal a little bit. After a few seconds, it will idle.