Idle problem

[cramirez01v6]

i have a 2001 v6 mustang currently idles weird. Went you start it up it will idle high for a bit up to 1100 rpm then go to regular also sometimes when i turn the ac on it will idle low to around 400 rpm for a bit them back to normal. This car also has a exhaust leak but idk if fixing it will solve my idle. But lately it will like that when the ac is on when i come to stops to around 400. any help would be appreciated.

 

[jrod2423]

Never give it a thought if that was a problem but mine does the same thing except the ac, you just have to give a couple seconds to warm up and it will idle down and be ready to go. and im goin to take a wild guess your car is an automatic?

 

[cramirez01v6]

yeah automatic i was leaning towards the 5-speed but got a good cash deal on it.

 

[wmburns]

Does the AC "short cycle"? Are you low on Freon? If so, this could be the source of the problem. Why? The IAC maintains two idle trim settings. AC on and AC off. If low on Freon, the compressor won't run long enough for the PCM to re-learn the AC on IAC setting.

For low idle:

• Clean the MAF. Use only a product designed for the job.
• Check for vacuum leaks. Especially between the MAF and the TB butterflys.
• Secondary ignition. Spark plugs and wires in good repair?

More information on how to trouble shoot IAC / Idle issues:

Is your mustang stumbling, dieing at idle or idling rough? - Page 14 - Ford Mustang Forums

 

[Yamkog]

Does the AC "short cycle"? Are you low on Freon? If so, this could be the source of the problem. Why? The IAC maintains two idle trim settings. AC on and AC off. If low on Freon, the compressor won't run long enough for the PCM to re-learn the AC on IAC setting.

For low idle:

• Clean the MAF. Use only a product designed for the job.
• Check for vacuum leaks. Especially between the MAF and the TB butterflys.
• Secondary ignition. Spark plugs and wires in good repair?

More information on how to trouble shoot IAC / Idle issues:

Is your mustang stumbling, dieing at idle or idling rough? - Page 14 - Ford Mustang Forums

Your problem sounds a lot like mine,i went to my local Ford Dealer and they Suggested to replace the idle air control valve which was approx $60.00 and Walla no more issues...