Hey everyone,

I have a question for you all.

I have been experiencing erratic idling . Here are the details:

- Battery connections were cleaned this weekend and computer was reset. After the reset the idle fluctuated for a while. I know this could be the computer setting the idle. It idles fine now with the A/C off.

- The most telling symptom is the car idles at 750 or so but the second you turn on the Max A/C, the idle bounces back and forth between 400rpm and 800rmp in a cyclic pattern. Every time.

- I find that the car wants to stall/rpms drop during low speed turning manuvers.

- Slight stall sensation when stopping.

- I typically spray some water under the hood of the car to get rid of the dust. I know better but often I don't cover any components but try to follow with a drive (however a few times there has been quite a time lapse). This may not be the issue but I thought I'd mention it.

I have searched the forum and have heard that it may be the TB. I will try to clean the TB this weekend.

Please let me know if you have any other suggestions!

Thanks so much,
Danny

 

TB is my first thought, and maybe the battery disconnect screwed with the PCM which doesn't know what to do with this crudded up TB. It worked fine before because it was built up slowly over time, and the computer could adjust slowly over time. When it was reset, it just doesn't know what to do now.

Just my rambling thoughts.

 

Thanks steve. Your logic makes sense to me.

I will try to clean the TB and see if that helps.

Anyone think something else may be the cause? Should I clean anything else? Advise please.

 

Dan,

What was the outcome of this? I'm having the same problem, low idle, flucuating idle with a/c on (this is actually caused by the a/c brining the idle down below 500, then shutting off because it's so low, bouncing back to 7/800, a/c back on, idle drop/a-c off, etc). This started with me about 3-4 weeks ago.

I originally blamed it on the auto transmission, but after flashing back to stock, removing neg battery cable, reinstalling tune, I had the same problems.

Did cleaning TB fix this?

 

Hi everyone,

I have a similar problem with my 2005 auto GT. 90% of the time when at stop the idle is fine but suddenly it just drop and the engine stop... it's kind of a pain when in the middle of the traffic I have left the car to my Ford dealer over here in Switzerland but they could not find anything wrong.... I dont know about you, but I feel like the auto gears change is not as smooth as it was before, could it be linked to the way the auto tranny is handling the gears change ?

Thanks for your help.

 

My dealer replaced a cam last month and I had this exact issue afterwards. It ended up being the TB was dirty.

 

I had that exact problem twice and the throttle body was replaced twice!

 

Recently had the same problem. It started after I unplugged the battery trying to reset the computer due the speedometer not working at all. Still trying to fix the issue...but any way. The idle was fine until the AC was turned on...then the idle would fluctuate and would try to stall when we were coming to a complete stop. I found that it was a combination of two things. The TB being dirty and the computer trying to set the idle properly again. Try removing the battery cables, and cleaning the inside of the TB to ensure that it’s not sticking. Reconnect everything and start the car. Let it idle for a minute or two…then turn the AC on max. Let the computer regulate the idle and see if that works. It did for me…hopefully it’s not a short term solution. Hope this helps…if anyone reading this has had speedometer issues I could sure use some help with that! Please see the speedometer problems post. Thanks!

 

I have been experiencing an idle drop but only at being stopped in drive. Sometimes the throttle safe mode dash indicator has come on with this but can always be reset with shutting off and restarting the engine. It doesn`t hold a code. I did a TB clean and it hasn`t helped. This is a once every week or two event so I`m not getting to upset with it but would like to see it fixed.