When I start the car it idles fine, but once driving, it will start to idle between 1500 and 2000 rpm. I opened the hood and made sure the throttle was closed, which it is. Can shut the car off for a min. Start back up and idles fine. Which leads me to believe that it's not a vacuum leak. Any Ideas?

Thanks
Mike

 

I'd still get a can of carb spray and look for a vacuum leak. Check the idle air control as well. It could be stuck or a wire leading to it could be broken. No SES lights right?

 

Hmmm ... he didn't mention it, but I wonder if he's got a leak in the vacuum booster line going to the brakes ??

 

Brought it in, had it connected to the scan tool. It was throttle position sensor. Thanks though

 

Hmmmm ......

Another defective throttle position sensor. I'm beginning to think there's a rash of failing TPS sensors out there.

 

third gen S cars seem to be more problematic than the 1st gens let alone the second...maybe they started sourcing cheaper parts
dunno

 

Scan tools are down around $100.00 now and it almost makes sense to purchase one as a diagnostic tool. You can just about pay for it the first time you use it.
I bought a Drive Belt automatic tensioner removal wrench this year. I finally got tired of fighting the tensioner which is usually located where you can't even see the dang thing now. I needed multiple times while changing the alternator on that stupid Focus.

 

I took it to a shop, the scan tool said Throttle position sensor, replaced that, didn't fix it. Replaced the IAC tonight, and it still idles high! Once I shut the engine off, and start back up, it will idle back down to 800. idles fine until I start driving again. Will get up to speed, push the clutch in, and idles about 2000 rpm. Shut the engine off, start back up, and idles back at 800. Anyone know what scan tool is the best?