Do I need my coolant temp sensor?

[Matthew cone]

Just bought this 95 talon from a guy and I asked why the coolant temp sensor is unplugged he said the ecu doesn't need it but now the car won't start. Could the fact that it's not plugged in be the problem?

 

[Kryndon]

Well, there are two sensors on the thermostat housing; one which sends signal to the temp gauge which is only to show you a reading, and the other is the actual temperature sensor which reports to the ECU. If that sensor is unplugged, the ECU will never know what temp the engine is at, therefore making it run in closed loop all the time. You will still be able to start your car, but it will not run right.

Before you bought it, did he show you if it actually ran and drove? Have you checked battery voltage, spark plugs, does it even crank, no fuel?

 

[Matthew cone]

Well, there are two sensors on the thermostat housing; one which sends signal to the temp gauge which is only to show you a reading, and the other is the actual temperature sensor which reports to the ECU. If that sensor is unplugged, the ECU will never know what temp the engine is at, therefore making it run in closed loop all the time. You will still be able to start your car, but it will not run right.

Before you bought it, did he show you if it actually ran and drove? Have you checked battery voltage, spark plugs, does it even crank, no fuel?

Yes. I drove it for a few days and then it started stalling every time I came to a stop. It cranks. There is spark

 

[Kryndon]

I had a similar problem once where the rpms dropped so low that it stalled when coming to a stop. This was because the 4 wire plug/connector was not connected to the Alternator. You could check if yours is plugged in.

 

[Matthew cone]

I had a similar problem once where the rpms dropped so low that it stalled when coming to a stop. This was because the 4 wire plug/connector was not connected to the Alternator. You could check if yours is plugged in.

I'll definitely check that too then

 

[Matthew cone]

Yes. I drove it for a few days and then it started stalling every time I came to a stop. It cranks. There is spark

Here's a picture of the thermostat housing and then a picture of a new coolant temp sensor I bought. Does anyone know the colors of the wires the I would have to splice in to connect to a new plug. And does anyone know what connector I would need? I did manage to start the car and it ran very rough almost like it's misfiring and idled at around 7-800 rpms

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[Joliet Jake]

I would get that temp sensor done, maybe go to a junkyard with a 2g dsm and go to town? Pennsylvania should have alot. I would also grab the ecu from behind the center console if its there. however i dont think that is what is causing your Talon to run like this...

from the sounds of it I would check your ignition timing and after test the curb idle speed and re position BISS screw and Fixed idle screw if necessary. make sure to read up!

 

[Vegas Smith]

Probably need to adjust isc, biss screw and tps like mentioned above.

 

[doubleclutch]

Be careful replacing the CTS. I had an issue where depending on where i bought it from the values cold and hot were way off. YOu should use some hot/cold water to compare the values to the service manual or buy it from mitsubishi.