Hi, I have a 97 cobra that i purchased about 6 months ago, I had ford put a new engine into it a few months back. Ive been having a problem with it when I come to a stop...the rpms come back down to idle, but sometimes they drop too low and stall the car. It mostly happens after the car is totally warmed up and ive been driving for a while, but It doesnt happen all the time. I was just wondering if anyone has had this happen to them and would know what could be causing this?? Could it be something as little as an o2 sensor or should I take it back to ford? Any suggestions or help would be greatly appreciated. Thanks

 

Do you have any kind of squeal in your engine?

 

sticky IAC valve. Remove, inspect, carb cleaner (not 1-1-1-trichlor), install, smile.

 

No my engine doesnt have any kind of squeal, Ya ill try cleaning the IAC valve and see if that does it. Would the IAC valve also cause my rpms to get stuck while im driving?.. its not for long but ive noticed that while im driving sometimes the rpms stay in one spot like i have my foot on the gas, and then they will start to drop down after a few seconds. It happens alot also when i come to a stop. Hopefully its just the IAC.

 

If it's sticky then it's not opening and closing like it should. The thing is normally open to a certain degree but not all the way all the time. If it can't maintain a working flow rate the idle will hunt like a mutherfuker and be all kinds of unpredictable.

I get the same thing from time to time on my 5.5 but that's tune induced and I'm too lazy to go in and fiddle with the IAC settings again.

 

Thanks for the help, i havent had the time to try and clean it yet. This weekend im just going to buy a new one and put it on. Its Less of a hassle and if its still doing it then i atleast know its not that. Thanks again