both cars while letting off gas pedal will stall & must be restarted. and sometimes it will take 10 to 15 mins.to restart. also, speed is sometimes not a factor. bonneville did stall once backing up. thanks for your advice.
If no codes, try cleaning the throttle body and IAC pathways.
thank you for the quick reply! what are the IAC pathways and where are they located.
This car will close the throttle plate completely when you foot is off the gas pedal. The ECM will control the idle sped through the Idle Air Controller (IAC). This is mounted on the side of the throttle body, and allows air to by-pass the closed throttle body. On the '94, it should be a plunger-style IAC that has a large hex on the outer body, like about 1-1/4", and screws in. It also has a 4-wire connector. I’m not familiar with the 2000 Bonneville, and the IAC for it.