Volkswagen: Hard starting, coolant temperature sensor, volkwagen jetta

Question
John, hello, I have a 1996 Volkwagen Jetta with a 2.0 liter gas engine.  When my engine is cold, it sometimes starts very hard (after about 10-15 tries, it will sputter and then slowly begin to idle).  It does this often after the outside temperature has cooled off. Once the engine starts, it runs rough until it warms up.  It then runs fine until it completely cools off.  I recently changed the fuel filter, air filter, spark plugs, distributor cap, and rotor.  I would appreciate any advice you could give me.  Eric  

Answer
i would advise you to change the 4 pin coolant temperature sensor (located in the coolant flange on the cylinder head). this relays the engines temperature to the ecu and alters the fueling to compensate for different temperatures. it sounds like yours is relaying that the temperature is normal running temperature constantly.