'99 Isuzu Tooper - stalling when idle

My car has been acting up over the past couple months. The car starts up fine in the mornings and I drive it to work everyday, but ocassionally in the mornings when I get to places where I need to let off the gas to coast to a stop it stalls on me. I can immediately start up again and go on my merry way, but it has been happening more often now especially when I go down a large hill that has a turn at the bottom where I have to slow down. I am not a car-guy so I hope somebody can give me a few ideas on the problem before I go on blind faith by what the local delearship tells me.

I’d probably start with cleaning the valve body and AIS. It could also be something like a throttle position sensor giving faulty data to the PCM. On a long downhill the PCM, depending on the “fuel management strategy” employed at the time, will often shut off the fuel injectors if the engine is warm. The transition out of this NO FUEL situation appears to be corrupted. The PCM can be reading a closed throttle beyond the point of you pushing your foot down. In any event, the AIS should maintain the engine at the minimum idle setting, which it isn’t. That’s why I say clean that first. That’s just a few $$ of throttle body cleaner and getting the air horn hardware out of the way.

Is the check engine light on? If so, many auto parts places will read the error code for free. That may help narrow the search. The ERG Valve was a problem in mid 90’s Troopers. Could also be a small vacuum leak that causes an uneven idle.