OK, so I just bought a 91 Firebird 305 TBI, the car idled rough the first time I ran it, it just died when in gear, turns out it had a loose spark plug wire, fixed that, now the car keeps running rough and canīt seem to keep idle speed either in gear or not.

I did a search and found out the CTS can give this kind of issues, I went to the local Autozone and bought a new one since it was cheap.

I came back and turned on the car and it still ran rough(not so much as before) and unplugged the CTS and the car idled fine, then began dropping idle RPMīs until it died a minute or so after.

I went ahead and installed the new CTS and plugged it back, the car just wonīt maintain an idle, it keep revving up and down and unless it was given gas, the car just died.

I unplugged the CTS again and it ran fine, then dropped RPMs and died, just like before.

Is there anything Iīm missing here? The car seems to Idle better without the CTS connected but itīs a brand new sensor, can this new sensor be defective too?

Do I have to unplug the Battery from the car in order for the computer to erase any codes?

Whatīs the proper procedure in replacing a Coolant Temperature Sensor?

ANY help is greatly appreciated.

 

Clear the ecm & drive it to get some fresh codes. Unhook the battery to clear it.

 

Thanks!

Disconnected cable for 5 minutes, then ran car again and it kept idling way too rough, I canīt check for codes right now since I donīt have an scanner and the car just wonīt drive, should I keep running it for some time giving it gas?

I just canīt think of anything else causing this problem, I mean, if I remove the CTS connector, the car will idle fine but then it will die after a minute or so which I think is normal, or isnīt it?