Hi all i have a BA Fairlane that when i start cold doesnt idle up for warm up like a choke now my partner has a BA Fairmont ghia and on start up it idles up perfectly and once warm the idle drops back down i also had a BA XR6 that i recently sold and it would warm up the same way without an issue ,now i cant seem to find a coolant temperature switch so does anyone know how the Barra 182 ecu knows what the coolant temp is to set the idle does it use the temp sender for the gauge or is there another sensor?
The temp gauge on the cluster is working fine and the thermo fans are working correctly but it does not go as good as the Fairmont ghia that my partner has hers accelerates much better not that my Fairlane Is terrible but definitely not as responsive as her Fairmont (both have similar km) does anyone know if the BA Fairmont ghia and BA Fairlane ghia have a different ecu programme and if so could ford reflash my Fairlane with the Fairmont programme? and does anyone know how much a reflash costs ?thanks in advance

The sensor is on the back of the cyl head, the easiest thing to do would be a scan and you can watch live data, for instance % of throttle opening on start around 18%, desired throttle opening on start, and actual, temp degree's, signal voltage to the pcm and so on. Be careful if you are going to check the sensor voltage because it has two functions and two different signal voltages. Before you see some one to fix it, give the throttle body a clean with some carbi cleaner on a rag, both sides of the throttle plate or take it off. pull the keep alive memory fuse or disconnect the battery after you check for codes, and You don't need a flash.

i have replaced the coolant temp sensor my throttle body was already clean but i swapped it with the one off my Fairmont ghia (also clean) still no good it doesn't idle up when cold but the Fairmont doe's and my XR6 that i sold to my sister does ,now not 100% if this is right the coolant sensor on start up when cold tells the ecu that it is cold the ecu then tells the stepper motor on the throttle body to up the idle to around 1000 rpm until the sensor says its warm and the ecu tells the stepper motor to back off the idle down to around 800 rpm? so now that i have replaced the coolant sensor and the throttle body i'm left thinking the only thing left that could be causing this problem is the ecu ?will put the scan tool on it and see how it looks

Scan tool is the way to go, it doe's not have a stepper motor it is a dc motor duty cycled by the pcm. On a cold engine it should start around 18% throttle opening and around 1000rpm and come down as the sensor voltage changes. If you don't have other problems with the engine except for when it is cold, I don't think it will be a pcm problem, What is the cyl head signal voltage when the engine is cold, check it at the sensor and the pcm.