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I have a 2003 impala 3.4 and have installed a new crankshaft sensor,camshaft sensor and IAC Sensor which seems to keep malfunctioning every morning, I have to reset it every day and after every reset the car runs smooth can anybody help me to keep the Iac sensor running normal..its not the maf sensor either.
 

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I have a 2003 impala 3.4 and have installed a new crankshaft sensor,camshaft sensor and IAC Sensor which seems to keep malfunctioning every morning, I have to reset it every day and after every reset the car runs smooth can anybody help me to keep the Iac sensor running normal..its not the maf sensor either.

How do you know the IAC valve is malfunctioning? How do you reset it? Why did you replace it?

Did you clean the bore that the IAC valve fits into? Is it sticking and causing a high idle? Did you use an ACDelco part, or aftermarket?
 

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Thank you for responding, yes I cleaned out the whole throttle body and I don't believe the IAC sensor could be sticking. How I reset the sensor I found it on an Autozone help site with the sensor replacing guide.. You push the gas peddle in and depress the accelerator slightly then start the engine for 5 seconds 3rd step turn the ignition to the off position for 10 seconds. restart the engine and check for proper idle operation, and of course this is done after unplugging your battery, the only thing that I think could be the cause is, that after every reset I have done the car has only been driven short distances and has not picked up speed more than I at least have to say 25 mph.
 

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Thank you for responding, yes I cleaned out the whole throttle body and I don't believe the IAC sensor could be sticking. How I reset the sensor I found it on an Autozone help site with the sensor replacing guide.. You push the gas peddle in and depress the accelerator slightly then start the engine for 5 seconds 3rd step turn the ignition to the off position for 10 seconds. restart the engine and check for proper idle operation, and of course this is done after unplugging your battery, the only thing that I think could be the cause is, that after every reset I have done the car has only been driven short distances and has not picked up speed more than I at least have to say 25 mph.



I think the problem lies with repeatedly disconnecting the battery. This causes the computer to revert to a default mode for the idle speed and transmission shifting (which can cause a driver to think there is an issue with the engine, due to lack of smooth shifting).

I would drive the car at various speeds for 25-50 miles, and see if the system adapts (learns) the idle speed and transmission shift points. Then see if you believe the problem is corrected.

Did you use an OEM ACDelco IAC motor? I do NOT use aftermarket parts, and have found that OEM parts (especially electronic sensors) are the best to use.

Let us know what you determine.
 

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Thank you I appreciate the help and i finally stopped resetting the system and have been letting it run and tbe car has been running a lot smoother and has only stalled out once when reversing but turns back on, its most likely what you said but if the issue continues I will just take it for a diagnostic check.. All parts that have been replaced are ACDelco or OEM certified. Once again thank you for the advice I will keep everyone posted
 
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