I have a 3.9 V6 that has a tendency to stall, most of the time when backing up. How can I narrow down what is causing this problem?

 

Stalling while on the gas and rolling or when you let off the gas or when you apply the brakes to stop? Have you checked anything yourself?

 

It is when rolling backward and if I do slightly push the gas it will not stall, I haven't noticed anything that tied backing with this condition. I have not personally tried anything in the past except have a mechanic check focusing on the idle sensor. It doesn't seem to get any worse, although it can be a safety hazard.

 

does it run OK? About what RPM does it become unstable below?