I have scanned using freescan everything seems to be normal except my coolant temperature it reads -40 degrees celcius, the only thing i figure is the coolant temp sensor is not working right would this cause the car to run rich?

 

Yes it would, once the engine warms up.

Check the wiring before replacing the sensor...could be a bad wire or connector.

 

What values should i see on the wires? 12v... 5v?

 

Neither, the sensor is a thermistor, a temperature sensitive resistor. Take a look at Injuneer's web page to get the temp v resistance values for the sensor....

 

http://shbox.com/1/4th_gen_tech2.html#ect

 

Thanks guys i appreciate the help

 

Or you could always check out Rob's page....

 

The PCM circuit supplies 5V without the sensor attached. The sensor resistance causes the circuit voltage to vary over the range of less than 1V to more than 4V. I'm surprised you don't have a code.

 

OBD1, Ive seen this happen a lot on TBI trucks, They will come in flooding to death, barely running and won't show a code

 

I did the test on shoebox page. I have 4.16k using the ohm scale at about 64 F.

4.9v connecting red lead to yellow wire and black to black

and 0.2 on ohm scale connecting red lead to black wire and black lead to ground
i think everything is working ok on the wiring side, i put a new sensor in but nothing has changed still reads -40 fahrenheit and theres so much fuel its leaving a black spot on the ground underneath the exhaust.
Is there any other reasons it may be reading -40 for coolant temp?
I also measured the sensor in ohms and it read 2900

 

Are you checking the correct coolant temp sensor - the 2-wire sensor in the water pump housing?

Did you check the voltage at the harness connector, between the yellow and black wires, with the harness connector off the sensor?

 

Yes it is the sensor in the waterpump. I did do those checks and everything turned out proper.

I replaced the connector with a new one and problem solved. Not sure why the tests showed that everything was fine. I had the same thing happen with the icm connector before.