Can anybody tell me what (and where) the TX3 sensor is? Supposed to have something to do with temperature readings being sent to the ECM.

 

Hmmn,

Never heard of it referred to that way...but the ECM received the Temp reading from the CTS (Coolant Temp Sensor) located in the front of the intake manifold.

There's also a IAT/MAT sensor in the plenum as well as a temp sensor under the plenum for the EGR diag to be read on.

Where did you get the "TX3" designation?

 

Yes, you are right about the TX3 sending the temp reading to the ECM. I presume it is the sensor located in the intake manifold. There are 3 temp sensors in total.

1. between 6 & 8 cylinders - turns secondary fan on
2. between 1 & 3 (I think) cylinders - sends signal to the gauge
3. in the intake - sends the signal to the EMC I believe.

RMK

 

I have never heard of a "TX3" sensor before. I have never read about it either. Where does that terminology come from? Just curious...

 

All of the people I have heard use the term are Europeans. I was talking to a car buddy last week and he was referring to it as a TX3.

 

The Euro connection is correct for me as well, cause I live in Sweden. The mechanic I spoke too seemed to do a lot of work on Chevy trucks and vans so maybe that is actually where the name comes from?

He also said that particular sensor was prone to cause problems when starting the car and that it (or the thermo or plugs) was probably why my T/A is taking longer to start these days...

 

1 and 2 are not located in the manifold. They are located in the water jackets of the heads.

Inside the actual manifold there are only 2 sensors on CS injectors cars. There is one temp sensor for the ECM and the other is the CS injector switch, but I have not heard of it called TX3. Those are the ONLY two sensors that send coolant temp to the ECM.

 

Yes, I forgot to mention that.

 

I think your buddy has a nut loose...

The "TX3" sensor is a temp sensor, but the TX3 is (I believe) the Standard Ignition part # for it.

Call an auto parts store that carries Standard and ask them.

 

The part you may be concerned with the called a "Cold Start Control" in GM terms. On a stock '87 TPI, it is located in the front coolant crossover on the intake:



If this sensor/timer/recycle control fails (yes, it has three purposes) you may not get the additional fuel from the cold start valve (injector) to provide easy cold air starting.

 

Hey!

Many thanks for the picture. I´ve been flipping through my Haynes book trying to find it!

I ordered a new one today along with some other stuff for the spring-tuneup.

/Joe
Sweden

 

The sensor between 1-3. I was wondering any one knows the part number for the sensor because if it does send the temp to the gauge i need to replace it because when i took the heads off of my car the top of it broke off and now my gauge doesn't work. So if and one can help me out.

 

Exactly.