low RPM i drive

[chrysl300c]

Hello every one,

I noticed lately that when i stop the car waiting to go again that the RPM drops down to 500RPM while the stick in D, when mpve it to N the RPM jumps to 725 RPM and stays there even when i move the stick to D.

I cleaned the TB and did not solve the problem.

Any idea? I will appreciate your help.

[MADDOG]

hmm...idle speed variation without any throttle input, right? Mine hunted for an idle RPM for a while after I got the car tuned but now it's settled in to the same idle in D (700 RPM) and rises a bit if idling in Neutral, which is normal.

There could be plenty of reasons for idle variation: vacuum leaks past the throttle, clogged idle air passages, bad or clogged idle air control valve (IACV), dirty throttle body, faulty electronic throttle, problems with the wiring or connectors, ECM problems, etc. Sometimes the carbon deposits in the idle air control valve can cause it to be stuck open or closed. Sometimes even low coolant level can cause the idle fluctuation and the code P0505. Problems with the EGR and EVAP systems also can cause the code P0505. If the idle air control valve or the throttle body is dirty, sometimes cleaning the either one can solve the problem. However, in many vehicles the idle re-learn procedure must be performed after the repair is finished. In some cars, the idle re-learn procedure is performed with a scan tool, in others the ECM re-learns the idle speed after the engine is run for some time.

What I would do is make sure the coolant level is at the proper level and replace the IACV.

[chrysl300c]

Originally Posted by MADDOG

hmm...idle speed variation without any throttle input, right? Mine hunted for an idle RPM for a while after I got the car tuned but now it's settled in to the same idle in D (700 RPM) and rises a bit if idling in Neutral, which is normal.

There could be plenty of reasons for idle variation: vacuum leaks past the throttle, clogged idle air passages, bad or clogged idle air control valve (IACV), dirty throttle body, faulty electronic throttle, problems with the wiring or connectors, ECM problems, etc. Sometimes the carbon deposits in the idle air control valve can cause it to be stuck open or closed. Sometimes even low coolant level can cause the idle fluctuation and the code P0505. Problems with the EGR and EVAP systems also can cause the code P0505. If the idle air control valve or the throttle body is dirty, sometimes cleaning the either one can solve the problem. However, in many vehicles the idle re-learn procedure must be performed after the repair is finished. In some cars, the idle re-learn procedure is performed with a scan tool, in others the ECM re-learns the idle speed after the engine is run for some time.

What I would do is make sure the coolant level is at the proper level and replace the IACV.

MADDOG, Tanks allot man for your effort and time.

The RPM is steady. It just drops to 500 and when i move the stick to N or P it just jumps to normal RPM. I will check IACV and other things you mentioned and i hope i will not have to take it to stealership.

I will post what ever solve the problem.

Thanks again.

[MADDOG]

You said in D it drops to 500, then to 725 when in N or P, and then stays there when you put it back in D. If that is true then the IACV needs some attention. It if always drops back to 500 when put in D then that's too low and it still should be looked at.

[chrysl300c]

Originally Posted by MADDOG

You said in D it drops to 500, then to 725 when in N or P, and then stays there when you put it back in D. If that is true then the IACV needs some attention. It if always drops back to 500 when put in D then that's too low and it still should be looked at.

Yes sir, that is true. When i move the stick to D it stays in 725Rpm steady.

Now i am looking in the repair manual which i downloaded for the IACV so i can remove it for cleaning.

Can you tell me the location of both EGR and IACV? in all cars that i own b4, i knew the locations. But in HEMI, that is another story.

[chrysl300c]

Originally Posted by chrysl300c

Yes sir, that is true. When i move the stick to D it stays in 725Rpm steady.

Now i am looking in the repair manual which i downloaded for the IACV so i can remove it for cleaning.

Can you tell me the location of both EGR and IACV? in all cars that i own b4, i knew the locations. But in HEMI, that is another story.

OK, Finally i found that my car is not equipped with EGR!!!

And as the parts sales man told me that IACV is included in the throttle body!!!

Anyway, i think have to put up with that until it is time to change the whole part.