Mitsubishi 1.5 ECI 4G15. very very hard to start when the engine is cold but start very well when is warm or hot. many parts is changed, coolant sensor, spark plug and wires, rotor and distributor. etc,etc. I need your help....

 

Do a compression test.

 

The compression test is good, all cylinder is ok. my possibility is on the throttle body and idle readjustment, or ECU, or TDC, but I don't no how test this item.

 

How does the coolant look, does it miss a little when you first get it running. I am gonna bet you have a possible badhead gasket.

 

the coolant is good, no overheating, always in normal temperature.No leak for the coolant or oil. This morning my car run after 4 start, but the idle up and down, up and down.... last day, it's running after 10 start and my idle is ok. I don't no why is my problem.

 

You may want to switch to a different oil thickness... there are some made to help start engines in cold weather.