coolant temp sensor question

[soulweaver]

My wires came unplugged from the coolant temp sensor and I need a picture showing the stock sensor with wires plugged into it so I can see what wires go were. If any one can help I would appreciate it. I do already have a thread asking for this but it is long and drawn out and everyone kept going answering questions that were already answered. Thanks again.

 

[96ETT]

You mean your wires came out of the plug on the harness side or the plug came disconnected or what exactly happened?

 

[soulweaver]

the wires pulled out of the harness that plugs into the coolant temp sensor. So All I have is two wires not connected that plug into the coolant temp sensor on a 1g dsm.

 

[1992awdlaser]

It shouldn't matter which wire goes where since it is a thermosistor.

 

[soulweaver]

so any wire can plug into any terminal on the coolant temp sensor?

 

[1992awdlaser]

Yeah, it should work either way.

 

[96ETT]

Yea now that I think about it all the ecu needs is the resistance created by the temp sensor. So as long as both wires are connected and the sensor is in between them it should work.

 

[Harriz801]

It sounds wierd to here but yes the only thing the coolant temp sensor see's is resistance. When the heat in the coolant rises the resistance lowers, when the temperature in the coolant decreases the resistance increases.

Or it could be the other way around?

 

[steve]

It's a NTC sensor. As the temp rises the resistance drops. A disconnected sensor looks to the ECU something like it's -34F.

 

[soulweaver]

Thank you everyone. When the snow storm stops I will try starting the car again if it don't start I will be updating this thread

 

[95mitseclipsegs]

Quick question on the temp sensor and the ecu, if when the sensor is disconnected from the computer and it reads -34, will the car still start? Is this an easy way to test and see if the sensor is bad without having to pull the sensor out of the hole that it threads into? If so, this would help me diagnose whether my sensor is bad or not.
Also on a side note for the sensor, the car is a 95 GS-t. Could I use the sensor connector off of a RS or GS if the plastic clip is broke so it doesn't clip onto the sensor anymore?

 

[1992awdlaser]

I have never seen a dsm that will start with the sensor disconnected. The only way they would start was with starting fluid and then it wouldn't stay running.

 

[steve]

With the sensor disconnected the ECU pretty much floods the car with fuel.
When it's really that cold fuel doesn't atomize very well and the ECU enriches the mixture in an attempt to get some of it to ignite.

 

[95mitseclipsegs]

If I were to buy a new sensor and just hook the wiring up to it, would that be a way to test the sensor since a replacement one is only $20 and then I would not have to pull the sensor and put it in boiling water in order to test it out?
Also, if the sensor is bad, would the injectors still open up and allow fuel or would the computer shut off the injectors completely?

 

[1992awdlaser]

Yes, that is a perfect way of testing it if you want. Yes, the injectors will still open.

 

[chicagoavenger]

I have never seen a dsm that will start with the sensor disconnected. The only way they would start was with starting fluid and then it wouldn't stay running.

Mine does takes a few cranks but runs fine after that. My 91 broke off and the same thing happened.

 

[soulweaver]

Ok that didn't fix anything. My car still cranks and doesn't start. It has compression, fuel, and spark. Brand new ECU (I just went through two of them thinking they were the problem). What steps should I take now to see what could be wrong. All my wiring is fine so please don't suggest that. I have went over them 100x's.

 

[Matsugi69]

sorry to bring back an old thread but i think i'm having the same problem

my 99 gst with a recent 6-bolt swap is running like crap. hard start, rough idle, no power and bogging down real hard. if i remember correctly my coolant temp sensor was unplugged when i got the car back (its back at the shop now so i cant look for sure) would the sensor being unplugged cause all of this?

side note: CEL is on (havent pulled yet) and my temp gauge on the dash is not working.