Coolant temperature sensor '93 Dakota

Does it look like this:

Are you sure that you are looking at the correct sensor? If the reading was too low, the gauge should be toward the high side.

If I unplug the sensor and turn the ignition on, the gauge reads low (all the way to the left). If I short the lead (Still unplugged)to ground, the gauge reads high (all the way to the right). So I am confident I am dealing with the coolant sensor. It is just behind the alternator.

The service manual suggests the correct resistance should be between 10k and 13k at 70 degrees. The sensor reads 2k. I haven't checked the sensor with the engine warm. I know this seems backward and the gauge should read high, but 2k is not a normal reading, so I thought I would change out the sensor. By the way, the temperature gauge has read low since I bought the vehicle last year.

The only reason I am concerned is that I am still having stalling and backfiring problems and have replaced the catalytic converter, muffler, distributer cap and rotor, spark plugs, ignition wires, O2 sensor, fuel filter, air filter, and EGR valve. I have also checked for vacuum leaks. So I am trying to fix anything that is possibly related.

The backfiring occurs when I am driving at a constant highway speed and encounter a hill. As I gently apply more throttle to maintain the speed, the engine will briefly stall and backfire through the exhaust. If I let off the gas for a few seconds, the engine will begin to run smoothly and everything seems normal. On a 400 mile trip, this may happen 2-3 times.

Any ideas?

Thanks

TB> Are you sure that you are looking at the correct sensor? If the reading was

No, the pin on my sensor is a flat pin about 1/16 wide.

I guess, I am going to take the sensor out and see if there are any part numbers or other information on it.

It looks like it may be hard to get at as it is behind the alternator and other stuff.

Thanks

Tom Lawrence wrote:

Why are you screwing around with the sender for the dash gauge in order to solve a driveability problem?

As for ideas; you might want to check the distributor for worn out bushings.

I will check the distributer bushings and the distributer position sensor as well.

Thanks

There are two distinctly different components;

1) Temperature 'sending unit' which inputs to the dash gauge. 2) Coolant temperature 'sensor' which inputs to the PCM according to coolant temperature. Device #1 has nothing to do with engine operation other than to let you know if the engine is overheating, and it's not very good at that.