I have a 96 passport aka rodeo with some blazer parts. I just had this problem, but I would stall. Replaced the Idle Air control motor, Didnt work, Throttle position sensor, didnt work, then the Intake Manifold Gasket, worked. I havent had any problems in the past 2 months since. Not saing that it is your problem but something to look at. Pretty common on Isuzus from what I understand