99 olds silohuette/ Hard to start

The 4.3 goes through distributor caps and rotors, try replacing those first. Its not so much the cold weather as it is wet weather.

Could be a number of things, but I would start with the engine coolant temp. (Ect) or air temp sensor. These will control your air fuel ratio and make it hard to start. I had a vehicle which started great when cold, but started hard when warm.

Replace tempature sensor

model with coil fitted check this as when they over heat they stop sparking. also the spark plugs and leads, up graded model with electronic timing check the dis pack and then the spark plugs and the leads, leads can check with meter, if hard or stiff leads replace them as this can mean they will crack with engine movement. check spark plug gap to your recommended speck for your engine code. coil should be replaced every 5 years or depending on your driving times these can very depending on coil fitted. dispak type if it has any cracks in the casing replace as water could of damage the internal coil.

you might have problems with the coils
check the temp of the coils when it stops working
if faulty they heat up alot

i found that a crank sensor was my trouble its fairly reasonable ,i would try that

Sounds like the coil has gone bad. This is usually the syptoms of this. When it is in the non crand status cool the coil down quickly with ice and see if it doesnt crank.

Replace the thermostat. If thermo is stuck open, coolant only heats up when there is no flow over radiator(idle) and then cools down when driving. Also, check coolant level, same response as stuck thermo.

when it cranks and does not run does it have spark?

try cycling the key on and off 5-6 times before cranking. let me know what happens