Idle Question

[Antbankstwo3]

When I start my car cold, it starts up fine. But when I put it in gear, it acts like it wants to die for a couple seconds then adjusts back to a normal idle OR sometimes it will adjust to a high idle then settle back to normal. However, when the car is warm, it does not do that. Otherwise it drives fine.

Any ideas?

 

[mikestertwo]

Check your TPS and IAC adjustments. Also check for vacuum leaks. Could even be a weak or bad O2 sensor.

 

[TurboTdr3.8]

You do not have any specs on your setup so it would be hard to know what is going on with your car , what you are saying they could be several problems making it do that .I have 1 car that does that sometime and it is just the nature of the beast in my case , I have learned to live with it as it is far from stock .

 

[Antbankstwo3]

Check your TPS and IAC adjustments. Also check for vacuum leaks. Could even be a weak or bad O2 sensor.

Thank u! I will double check that!

 

[Antbankstwo3]

You do not have any specs on your setup so it would be hard to know what is going on with your car , what you are saying they could be several problems making it do that .I have 1 car that does that sometime and it is just the nature of the beast in my case , I have learned to live with it as it is far from stock .

Yes! That makes sense! I replaced or upgraded several things on the car. Here what I've done...

New parts:
Denso O2 sensor
IACV (set about 28, TPS .42)
LT1 MAF & Translator (set MAF "3, WOT "0")
Replaced all the vacuum lines & check Valves
3" Down pipe & Exhaust
Spark plugs & Wires
IAT sensor
PCV
50 lb injectors
5.7 TT Chip

Not sure if I left anything out or if that helps. I don't really mind that it does it since it doesn't affect the driving, but if I could fix it I probably would.

 

[TurboTdr3.8]

Might can take the IAC out and clean it and the clean the Tbody and see if that helps any or you might unplug orange wire at the battery and reset computer and let it relearn .

 

[Antbankstwo3]

Might can take the IAC out and clean it and the clean the Tbody and see if that helps any or you might unplug orange wire at the battery and reset computer and let it relearn .

Got it! Thank u!

 

[earlbrown]

Bring that IAC number down and don't forget to reset the TPS after opening the throttle blade.

 

[Antbankstwo3]

Bring that IAC number down and don't forget to reset the TPS after opening the throttle blade.

Thanks Earl! I'll get that done!

 

[GNRick]

Bring that IAC number down and don't forget to reset the TPS after opening the throttle blade.

His IAC is already at 28. How low should it be?

 

[earlbrown]

In drive, it's probably in the 40's. Even higher with the air on.

If the IAC is way open the throttle blade is damn near closed to cause it. When initially cracking the throttle, just a few degrees of rotation cause the airflow to increase a BUNCH. While the TPS reports very little voltage increase. Its made even worse with larger throttlebodies.

I like mine to be as low as I can get it while still reading anything greater than 0.

 

[TTA308]

His IAC is already at 28. How low should it be?

IAC 8-12 idle, TPS 42 key on eng. off seem's to be a sweet spot for most.

 

[Antbankstwo3]

My IAC just read 21 today. It's the lowest I've seen it.

IAC 8-12 idle, TPS 42 key on eng. off seem's to be a sweet spot for most.

WOW! 8-12. I wouldn't expect that. But always learning.

 

[1fastcobra]

http://www.gnttype.org/techarea/faq/IACresetscan.html


20-25. Is where u wanna be
But every car is a bit diff
Depends on mods
But this is your target !!!

 

[1fastcobra]

http://www.turbobuick.com/forums/threads/bad-iac-valve.381349/

One more to to help u start over from zero