Is this normal for a GTO?? Idle question... - Pontiac GTO Forum
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post #1 of 9 (permalink) Old 01-16-2007, 05:45 PM Thread Starter
 
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Is this normal for a GTO?? Idle question...

I just got a new 2006 GTO, love the car but I think there might be a problem with the idle, can you guys let me know if you think this is normal or a symptom of a problem:

here is what happens: driving the car in 6th gear at about 2000 rpm I put into neutral and let off gas pedal, I notice that as the idle is dropping from 2000rpm, at around 1200 rpm is has a slight "bump" back to about 1400 rpm and then resumes its drop to the normal 800 rpm or so. This does not happen when I just rev the engine, if i rev without load on the engine the idle behaves normal. I only experience this problem after load is exerted on the engine, and is most noticable in 5th or 6th to neutral...

Is this normal??? Thanks in advance for any feedback!
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post #2 of 9 (permalink) Old 01-16-2007, 06:03 PM
 
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mine does that all the time. i have attributed it to the drive by wire system. my understanding on how it works is it senses engine speed and tries to maintain a certain speed so it feeds more fuel and air hence the blurp up. i have noticed this with just loading the clutch at idle in traffic and letting up right before the biting point. i think it is normal but this is the only 06 gto i have experience. 05 should have the same problem. also this is the only drive by wire car i have been in long enough to notice it's tendancies. this will be my last drive by wire because of the funky ways it responds but the accel pedal does have a decent engine input feeling. i'm no expert but this is what i have gathered. let the experts chime in
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post #3 of 9 (permalink) Old 01-16-2007, 06:11 PM
 
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Quote:
Originally Posted by ohmy View Post
I just got a new 2006 GTO, love the car but I think there might be a problem with the idle, can you guys let me know if you think this is normal or a symptom of a problem:

here is what happens: driving the car in 6th gear at about 2000 rpm I put into neutral and let off gas pedal, I notice that as the idle is dropping from 2000rpm, at around 1200 rpm is has a slight "bump" back to about 1400 rpm and then resumes its drop to the normal 800 rpm or so. This does not happen when I just rev the engine, if i rev without load on the engine the idle behaves normal. I only experience this problem after load is exerted on the engine, and is most noticable in 5th or 6th to neutral...

Is this normal??? Thanks in advance for any feedback!
It's just the Idle Air Control valve catching up with the quick release of the throttle plate. The DBW system is trying not to kill the engine.


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post #4 of 9 (permalink) Old 01-16-2007, 08:26 PM
 
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The main reason is to clean up emissions.
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post #5 of 9 (permalink) Old 01-17-2007, 12:43 AM
 
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Haha....you should try it with a lopey cam! My idle is all over tha place....but always settles back to nice thumpy dumpy 900 rpm.
Dang drive by is for the birds! Wonder whos genius idea that was.

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Last edited by Route 66; 01-17-2007 at 12:45 AM.
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post #6 of 9 (permalink) Old 01-22-2007, 01:38 PM
 
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There is also somthing in the PCM called somthing like "feed foward algra rthym" That tries to predict what you are going to do next buy moving the TB and A/F ratio, so its ready to launch incase you sunddly floor it and have better reaction time. Maybe that is what you feeling maybe.

But like PHOTOGOAT said its your Idle Air Control valve most likly what you are feeling. This lets enough air in at idle with the thorttle plate closed till you press the gas and move the plate.
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post #7 of 9 (permalink) Old 01-22-2007, 02:12 PM Thread Starter
 
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Thank You all for the feedback, it was much appreciated, after reading what you guys said I guess this might not be a problem after all, just a the way they designed it... Thanks again
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post #8 of 9 (permalink) Old 01-22-2007, 05:52 PM
 
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Glad to help, most cars have the idle valve but you dont realy notice it. Just seems to be more noticeable with are 400HP LS2s
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post #9 of 9 (permalink) Old 01-22-2007, 07:26 PM
 
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Idle strategy may be the case or pcm changing timing because drive by wire eliminates idle air control valve.Manual trans vehicles usually hang the rpm between shifts to help stop jerking effect that can stress various components.
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