rough idle

i have been workin on this van for a long long time and finally got the check engine light to go off horray. but now there is a new problem now . the van is idleing very rough and wont stay running . it wont even idle well it idles but as soon as you put it into gear it dies in the drive gears or revearse. it is idleingreally low and i cant find an idle adjustment anywhere any ideas?

I am going to guess that this is your 1998 Windstar that you list in your profile.
Is this the 3.8L engine or 3.0?

There is no idle adjustment, that is completely done by the PCM.
If the idle seems too low in speed, you might check the Idle Air Control (IAC).
It is mounted to the upper intake manifold, right next to the throttle body (on the 3.8L engine).
It has 1 electrical connector.
This is a small, electrically driven, valve that the PCM uses to control the Idle speed.
It is a common failure for this to get some dirt into the threads of the screw drive....and stick.
Remove the 2 small screws that hold the IAC in place.
Spray some oil based cleaner, such as Sea Foam "Deep Creep" or even some WD-40 inside.....flushing it out.
Then re-install it.
Of course, make sure that everything is connected back up......including the Throttle Position Sensor (TPS) and all the other electrical connections.
Make sure that the PCV line is all connected up also.

I have had horrible idle twice in my 00 3.8.

Once after air filter change - Ford dealer sold me a new MAF (I would try to clean this now). You could make it run by stomping on the gas but it smoked bad.

Most rescent was a shorted spark plug in #6. It idled bad and was terrible if you tried to drive it.