Idle problem

Your engine may have a vacuum leak or maybe the idle control valve is due for replacement.

replace idle control solenoid, check for dried out vacuum lines, pull each line off and look underneath on hot engine side which tend to split first. if rubber lines feels hard as a rock or split at end where hose plugs in, replace thjem all.

throttle position solenoid is a common problem on town cars to cause this problem, easy fix if u got patience, pain in the ass if u don't, located at back top of engine, ur tools will barely fit back there but u b very happy when u get the job done yourself. i have done a half dozen of these.so be ready to do the happy completion dance or U may be yelling :"What a stupid place to put the throttle position valve"!!

Rusty, Can you fill me in on where the solenoid lies? I’ve taken off the IAC and cleaned her well, going to put her back on. No codes thrown, not a mechanic by any means here, where would I find the solenoid?

2003 lincoln still idling high

I think he was referring to the IAC it is behind the throttle body and fun to get to. there is no throttle position solenoid It's a throttle position sensor and its on the side of the throttle body. It's a simple 5 minute job. I have a 2000 town Car and it had a bad IAC when I got it. I picked up a IAC off of a low mile from a wrecking yard and it did nothing to help it. The symptoms were when the temperature was below around 60 it would start making a loud honking noise like a goose. It has something to do with the harmonics of the entire intake system is my theory. I had read that if you took the IAC hose off and put a smaller hose inside it it could fix the problem. I did that and it fixed that car. I bought a 02 town car and it had the exact same problem though it would do it at 65 and got worse the colder it got. I had kept the IAC that I bought taking it off when it didn't help and remembered it and put it on the 02 and it fixed it! When it starts this act a tap on the accelerator will usually stop it but if your in traffic and go for the brakes while it is occurring it will be in a low vacuum situation and it doesn't want to stop so easily. My 02 was good for about a year and has just recently started doing it again.

a high idle is most likely a vacuum leak unless some where down the line it had a stalling issue and someone adjusted the base idle screw out to speed up the engine and now the computer can't control the idle and is trying to do so by shutting the IAC valve to lower it but the base idle screw is letting the air through the throttle body now and it can't help it. I just got educated watching a youtube video on this by a fantastic mechanic that walks you through the entire process telling you why and what he thinks is wrong and why he thinks it is and is 100% dead on.

That tells me now that the 200 has most likely a vacuum leak and the IAC didn't do any good and the 02 did have a bad or dirty IAC.

Without a good diagnostic computer these cars are next to impossible to fix without running the risk of creating more trouble or buying and replacing things that aren't broken. A obd scanner is helpful and in the hands of a competent mechanic can be a great asset but without a class or some real exposure you are at the mercy of lady luck.