1989 caprice stalls replaced water pump thermostat and radiator seems to stall when it get warm runs bad after rain or while raining check engine light comes on and i recently had my intake changed out because i broke a bolt in the thermostat housing couldnt get it out can a chevy man help me !!!

SOURCE: Windstar stalls when it rains and gets wet

this is from a different post

http://www.fordwindstarrecall.info/

SOURCE: car stalls in wet weather

Take a look at the ignition system, most likely there are coils and ignition wires on this car, but don't quote me on it. However, this is very likely on a seventeen year old car.
Anyway, if the wires are more than four or five years old, it might be a good idea to replace them as moisture tends to get into the insulation and cause a misfire or stall. (I had this problem with my '89 Tracer and it drove me nuts). Another issue is check the ignition coils and make sure there are no cracks as these will less moisture in and cause a misfire.

SOURCE: 95 jetta stalls and will not start in rain

The rain water is fouling the old coil wire, replace the ignition wires.

SOURCE: rain water leaking into heater intake

You can either replace the seal or hose, or use silicone and seal any leaks or gaps

SOURCE: stalls out when i am at a stop

a simple tune up should do it plugs wires cap and rotor when it rains moisture must be getting under the distributor cap and causeing it to skip or stumble and stall