Starts fine in summer/dosent in winter/takes 2-3 cranks before it holds idle . 99 crown vic

sounds 2 things here. fuel pressure regulator or the idle air control valve. I an goingwith idle air control valve

Idle air control valve. And/or gunked up throttle body, pcv port at throttle where mating to intake manifold.

Change your coolant sensor

have a 97 crown vic,
in warm weather it idles fine and run fine
now that its cold I have to hold at high idle to have warm up
for about 10 mins.
if I just start it the engine will die with out me holding on foot on the gas

I would replace the dle Air Control solenoid. I know its a guess, but its a common thing. when cranking the engine, the idle should flare high, and then slowly down to idle speed.

If you have more than 100,000 miles use high mileage oil. In the spring and summer use 10w30 and if it gets bellow -20 where you live use 5w30 in the winter

try changing the fuel pump relay...its on the driver side fuse box near the brake line

find the fuse fo the keyless enter and take it out and that way you will know if that the problem or something else give these websites a try www.autozone.com and www.alldatadiy.com cause the keyless enter will short out sometimes wish you the best of luck Michigan Man.

You may want to check the Vacuum lines if there are leaks. Check also Fast Idle Thermo Valve, which controls the idling at cold starts. If you have a carb, check the idle up valve.

yea its what connects the steering wheel with a ribbon for a solid contact and its is always being tested to make sure there is a connection.