could a bad coolant temp sensor cause

What year is the car

The temp sensor would not cause your problem Your intake air control valve can cause your problem. Clean it first and clear the codes and see what happens

the idle air control motor has no effect on the operation at wide open throttle. check to see if there is debris blocking it or keeping it from closing. make sure there is proper resistance if you bench test it. as far as the coolant temp sensor goes. if its out of range you should probably replace it as well. if you can hook up a scan tool and datastream while the engine is idling in closed loop the coolant temp sensor should read -42 degrees (thats normal for a bad or unplugged sensor) also check for and damaged wires.

while you are cleaning your idle air control motor you are going to want to check for carbon buildup in the throttle body and as well as ON the throttle plate. the carbon accumulates on the inside edge of the plate and causes poor acceleration and poor air flow.

MAKE SURE ALL OF THE VACUUM LINES ARE HOOKED UP/GET HOOKED BACKUP!!!!


let us know what you find

The IAC would not cause a lack of power with the throttle blade open.

Edit: post overlap with Mike.

jhonda said:

My car seems to have real good power until the water temp rises to the second mark and above on the stock gauge but when it runs where it use to (the first mark and maybe halfway to the second mark)it runs good....any ideas.

Jason

Click to expand...

So at one point it has real good power, and another temp it runs good? Isn't that kinda the same?

Agreed with the others. A bad ect will make it run like Crap if it is out of range. If worried just ohm it out while it's warming up and check the readings against these specs. I took em from I believe Jrichker or Hissin, I saved all the important stuff like that in a text document so I can look back at it anytime......

Code 21 – ECT sensor out of range. Broken or damaged wiring, bad ECT sensor. Note that that if the outside air temp is below 50 degrees F that the test for the ECT can be in error.

The ACT & ECT have the same thermistor, so the table values are the same

ACT & ECT test data:

Use Pin 46 on the computer for ground for both ECT & ACT to get most accurate readings.

Pin 7 on the computer - ECT signal in. at 176 degrees F it should be .80 volts

Pin 25 on the computer - ACT signal in. at 50 degrees F it should be 3.5 volts. It is a good number if the ACT is mounted in the inlet airbox. If it is mounted in the lower intake manifold, the voltage readings will be lower because of the heat transfer.

Voltages may be measured across the ECT/ACT by probing the connector from the rear. Use care in doing it so that you don't damage the wiring or connector.

Here's the table :

68 degrees F = 3.02 v
86 degrees F = 2.62 v
104 degrees F = 2.16 v
122 degrees F = 1.72 v
140 degrees F = 1.35 v
158 degrees F = 1.04 v
176 degrees F = .80 v
194 degrees F = .61

Note that all resistance tests must be done with power off. Measuring resistance with a circuit powered on will give false readings and possibly damage the meter.

Ohms measures at the computer with the computer disconnected, or at the sensor with the sensor disconnected.
50 degrees F = 58.75 K ohms
68 degrees F = 37.30 K ohms
86 degrees F = 27.27 K ohms
104 degrees F = 16.15 K ohms
122 degrees F = 10.97 K ohms
140 degrees F = 7.60 K ohms
158 degrees F = 5.37 K ohms
176 degrees F = 3.84 K ohms
194 degrees F = 2.80 K ohms