Idle problem again.
 

Well just when I tought my idle problem was gone, the problem is back again. I did another diagnostic again and I got codes 22 and 52 which are the Coolant Temp sensor and the Knock Sensor. I replaced the temp sensor and I am still having the idle problem. But what I noticed is that when i disconnect the coolant temp sensor wiring connector, the car will drop the idle to normal working rpm's(600 rpms). I checked my coolant temp sensor wiring and it seems good. After I finished insalling the coolant temp sensor I did a diagnostic again and I only got code 52(knock sensor). Help?

Did you replace it with a dealer sensor or autozone special?

Knock sensor has nothing to do with idle.

The brand is WELLS and I got it from Auto Zone for $30.

That, my friend is your problem. I recall a week or 2 ago someone had the exact same problem. It seems that aftermarket coolant temp sensors for the 87-92 supra are not the correct resistance. One reason for this is that they don't make an aftermarket sensor for a supra so the parts store computer substitutes it for one that will fit but it has the wrong resistance values. Trust me on this, I went through the same thing with an 89 Taurus SHO. I kept getting sensors that were made for Taurus LX's. They fit, but didn't work right.

I know dealer sensors are more money, and they will have to special order it but it's the only one that works.

I guess I'll have to buy one from a toyota dealer. Ill post up what happend when I install the genuine toyota temp sensor. Thanks IHATEHACKS.

Curious....what is the part # of the one you got from the zone??

I just took it back to Auto Zone to get my money back, but on the reciept it says *061401 SU4007.

I've changed the coolant temp sensor and it only dropped the Rpms to around 1000. Now I'm going to calibrate my TPS sensor, I have aleady taken out the whole throttle body. But I see that the throttle stop (The little screw bit) isnt in contact with the throttle lever (The springy bit that gets pulled when you press the accelerator). Should I move the stop screw untill it comes in contact with the throttle lever?

You didn't cover all the threads with teflon tape did you? Cover only the last half of the threads. If you cover them all, it will mess up the grounding of the sensor.

How long did you drive the car for it to idle to 1000 rpm?

Has the TPS ever been off the throttle body?

Are you sure you are looking at the throttle stop screw? There is another "stop" that is used for the dashpot and it's right next to the throttle stop screw and is easily confused.

I did put teflon on all the threads, I will take it out and do what you said.

Drove the car for a few miles.

Yes the TPS sensor has been off the car.

Let me take a picture.