1999 Dodge Grand Caravan, 160k, tranny rebuilt at 110k. Intermittent problem - start car in morning, put in gear, engine shuts off. Have to gun it and drop into gear to get going. Once car warmed up runs fine. Problem may or may not occur later in the day. Had fluid/filter changed a month ago when these symptoms started. Nothing unusual found on magnet. Diagnostics check found nothing. What’s going on?
Idle speed controls can act funny. this would not be normal sticky idle speed control, but they can be really squirrelly. it is an air control device that is run by the computer, to maintain correct idle speed. They get sticky with age, and cannot respond fast enough to keep motor running.
I realize it can be other things, but this should be eliminated. When you start it, if you have a tachometer, it should go quickly to correct speed, which when cold usually is higher rpm than when warm. And, it should not run up and down a bit.
To remove the deposits from the throttle plate and idle air control valve, use Throttle Body Cleaner in a spray can. Instructions on can.