Join Date: May 2006
Location: South West Florida
Re: open & close loop
Open loop is when the car is cold and the O2 sensor has not heated up enough to put the computer into closed loop so that it can take over and make needed adjustments. In open loop the engine runs at full rich with no adjustments being made. IF you have a bad O2 it could keep the car in open loop. As far as this being a repair procedure, its not. It is a status of the computer at a given time based on it's information of its current conditons. To check the car out on a scan tool the car needs to be brought up to tempeture putting the vehicle into closed loop. That is just basic principle as you can get into things like speed density and mass air flow and multiple O2s sensors that are both up stream and down stream etc etc. Is your check engine light on? or on before it stalls? I would start with a scanner to see if you have any stored codes in the computer and go from there. ALso your problem does not need to be computer related. It could be something as simple as the IAS (Idle air control seliniod) that is all gummed up with carbon or the little by pass hole in the throttle body is clogged. You can clean it out with some carb clean. Hope this helps!
Now restoring 68 Z22
Too Many Corvettes & not enough Camaros!
My skills in the shop are far better than my typing skills!