stalls until temp is up

My problem might be related... 99 Windstar Van. Idles high on start for about 40 seconds or so then idle drops off to about 600 rpm and Batt light comes on. Have checked the engine for all the vacumn leaks and can't find any. Is there a vacumn hose on the tranny that I can get at? O/D light comes on occasionaly at cruise and it does seem to have the kick in the butt start from a stop every now and then. Am thinking VSS is bad but haven't gotten to it yet. Get codes 171 and `174... lean running after driving for a while.

The usual suspect on a Windstar with those symptoms and codes would be the intake manifold gaskets.

Today while poking around the engine in frustration.... Found one of the two bars on the butterfly valves at the end of the manifold was not connected!! This may well be my problem. It is as you mentioned an intake manifold problem and I will have to remove the plenum to get at the controller. Will check the intake manifold at that time! Thanks a lot!!