I have a 99 Escort zx2 with about 270 k on it Just reciently it has started ti idle rough. Sometime when stopping for a red light it will idle at 1200 and slowly slow down to 800. Sometime it will idle at 600 rpm and slowly sped up to 800 rpm.The car is a standard with the 2.0 l DOHC engine. The timimg belt was done about 10 k ago.

Any help would be appreciated

If you are still working with this problem, inspect for an air leak and check the idle air control valve (IAC). Some people have had luck removing and cleaning/lubing the IAC, or it can be replaced if faulty.

check underneath the intake manifold. their is a pcv elbow that like to rip causing a air leak, and then check for gasket leaks. That elbow is on the bottom of the IM inside closest to the block.