I have a friend who has a 95 honda civic that won't start when the temp is cold outside . He has replaced the battery ,starter, alternator,coil and it still won't start when it is cold outside. Any suggestions. Someone said to try the engine coolant temp sensor. He is running out of money to keep trying things and then it doesn't help.

Yes, replace the Engine Coolant Temperature (ECT) Sensor, which affects fuel injector pulse width. The ECT Sensor is a temperature dependent resistor (thermistor), whose resistance decreases as the engine coolant temperature increases. It provides a richer mixture when cold, leaner mixture when hot. They become corroded, due to not changing the coolant frequently enough, flood the engine, and waste a tremendous amount of fuel. For identification purposes, the ECT Sensor has two wires going to it, while the ECT Switch has only one.

Thanks for helping. We replaced the coolant temp sensor, waited for it to get cold again and it still won't start when cold outside. This is the 1st honda I have worked on, is there something different I need to do.

I would focus on the distributor. When were the Ignition Control Module (ICM), rotor, distributor cap, and spark plugs last replaced? It could be that the spark is marginal in cold weather.

Did you get it fixed?? Did you check the main relay?? It's a common no start problem on hondas and it is temperature sensitive. Mine wouldn't start when it was hot outside or really cold and I replaced the main relay and it started fine. Listen for a loud click when you turn your key to the on position, you should hear a click when your check engine light comes on, then another click when the light goes off in about 2 seconds. If no clicks, replace your main relay. Mine is a 1990 honda civic though, not sure how similar our cars are though.