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Novive quesion about pcm and acceleration.

 
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2001Ls
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PostPosted: Fri May 11, 2012 6:19 pm    Post subject:  Novive quesion about pcm and acceleration. Reply with quote

I wanted to see if anybody has a little insight for me. Why is it that my car is very timid at low to medium throttle but when I go 3/4- 100% throttle it suddenly comes alive? Here I will try to explain, it's kind of like the driving has two different identities. Like when I try to give it a lot of gas it doesn't gradually jump in rpm, it suddenly gets up in the 5-8k rmp range and begins moving. My question specifically is why is there this sudden increase in power and rpm opposed to it being gradual? In my own thinking I would imagine the pcm reads the throttle position sensor and over a certain percentage it increases fuel injector flow? Maybe I am the only guy who notices the two sidedness of the car but just wanted to see your guys's 2 cents. Thanks.

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PostPosted: Fri May 11, 2012 6:23 pm    Post subject:   Reply with quote

The car downshifts

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2001Ls
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PostPosted: Fri May 11, 2012 6:32 pm    Post subject:   Reply with quote

ok thanks,

(please stick with me on this, I know I may sound a bit stupid)
So being that we have 4 speed automoatic (4l60e) what engine value sends the pcm a command to shift down from 1st to second, seoncd to third (etc.) ? Is RPM/ speed the value that controls shifts? Also to piggy back on this, rpm's drop on downshifts if Im not mistaken, what is controlling the injector flow and spark timing?

(do you know any deeper reading I can do on my own?) Thanks.

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PostPosted: Sat May 12, 2012 1:44 am    Post subject:   Reply with quote

2001Ls wrote:
ok thanks,

(please stick with me on this, I know I may sound a bit stupid) 4 speed automoatic (4l60e)

Thanks.


Wait, I thought the trans model was 4t65e?

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PostPosted: Sat May 12, 2012 2:12 am    Post subject:   Reply with quote

impala2k wrote:
2001Ls wrote:
ok thanks,

(please stick with me on this, I know I may sound a bit stupid) 4 speed automoatic (4l60e)

Thanks.


Wait, I thought the trans model was 4t65e?


it is

4L60E is a RWD transmission

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Last edited by Pitch Black SS on Sat May 12, 2012 2:16 am; edited 1 time in total
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2004 Chevrolet Impala
1982 Chevrolet Malibu
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PostPosted: Sat May 12, 2012 2:15 am    Post subject:  Re: Novive quesion about pcm and acceleration. Reply with quote

2001Ls wrote:
I wanted to see if anybody has a little insight for me. Why is it that my car is very timid at low to medium throttle but when I go 3/4- 100% throttle it suddenly comes alive? Here I will try to explain, it's kind of like the driving has two different identities. Like when I try to give it a lot of gas it doesn't gradually jump in rpm, it suddenly gets up in the 5-8k rmp range and begins moving. My question specifically is why is there this sudden increase in power and rpm opposed to it being gradual? In my own thinking I would imagine the pcm reads the throttle position sensor and over a certain percentage it increases fuel injector flow? Maybe I am the only guy who notices the two sidedness of the car but just wanted to see your guys's 2 cents. Thanks.


guessing this is your first car? or the first and only car you have ever driven?

The car simply downshifts, no magic about it, nothing special is happening in the PCM, non-computerized vehicles do the same thing.

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PostPosted: Sat May 12, 2012 9:59 am    Post subject:   Reply with quote

Im trying to understand the dynamics of rpm, speed, gear and how the pcm reads it all.

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PostPosted: Mon May 14, 2012 11:10 am    Post subject:   Reply with quote

http://www.powrtuner.com/index.php?act=idx

http://www.hptuners.com/forum/

Tiny Tuner

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