Rough idle on 1999 Ford Contour SE 2.0

Not having an IAC would only affect idle speed. A rough idle could be a weak coil, or injector among other things. It takes more spark and fuel to fire a cylinder when the engine is cold.
Are you getting a trouble code for any one cylinder ?

spark plugs work better when theyre hot so change spark plugs,

TPS sensor and IAC sensor.

mcdevito75 here, Sounds like a faulty voltage regulator, it"s 1 unit with the alternator, change the alternator, also the alt. supplies juice to the ignition switch, distributor abd plugs, thus a rough idle due to bad alternator.

check IAC operation will it idle with the AC on

Often, on the Escorts of this vintage, rough idle can be due to a leak in the vacuum system. With the engine running, listen closely for any tell-tale hissing sounds coming from any of the vacuum hoses. Check that they are all securely in place and the end-clamps are all tight. Also check that the PCV valve and the hose connecting it to the manifold are securely in place. Another possibility is the Idle Air Control (IAC) valve. If it is clogged or sticking, it can cause rough idle. Refer to a service manual to diagnose the IAC valve. Other things to check: make sure that the air intake is unobstructed and clean. You might consider cleaning the manifold and throttle body. Check the air filter and replace if necessary. Let me know if you have any other questions.

This is only a guess, because rough idle can be due to an infinity of reasons. On the Focus, assuming that the spark plugs and wires are all good (check that the wires are seated securely), then very often this is due to a problem with the vacuum lines or the Idle Air Control (IAC) valve. With the engine running, listen closely for any tell-tale hissing sound and try to locate it. Check that the vacuum hoses are all in good condition and that they are securely in place. The IAC is a little more complicated to check. Its job is to let air in when the throttle is closed. If it is not opening as it should then the engine will idle rough. One thing you can try is to remove the IAC entirely, leaving an opening for air to get into the intake manifold. If the engine idles better with the IAC removed, you will know that the IAC has a problem. It could be a problem with the IAC itself or with its circuit. Good luck, if you have any more questions let me know.

Check you (IAC) Idle Air control valve.

check to see if your map sensor is plugged in

change spark plugs if still haveing probs after that change fuel filter