Toyota Repair: EFI computer open loop, fuel pressure regulator, high mileage

Question
Hello Mike,
Have a '92 Previa with these symptoms: After it warms up, whenever it comes to a stop, it idles completely down and dies.  It'll start back up, and runs fine.  It just dies when you stop.  My mechanic says he can't read the computer as it is on "open loop."  He recently replaced the fuel tank filler neck as it had corroded.  We suspected moisture in the fuel, but ran a tank of gas through with some HEET in it.  Fuel filters were OK.  Any ideas before I take it in to the dealer?
Thanks

Answer
High mileage?Does it stall every time?
Does it stall cold?
Ive seen cracked rubber intake runner do that.
Could be a bad fuel pressure regulator.
Ive also seen EGR valves stick open when your going down the road so when you stop the car stalls out. Thats usually after a highway run of several miles.
I once saw a rag in the fuel tank do that. It would stick to the pick up in the tank when you stopped and stall the vehicle.Once it stalled the rag would drop to the bottom of the tank.

I dont know why your mechanic said what he said.
Open loop is a term used that means the vehicle hasnt warmed up yet it relys on stored info in the computer to make fuel trim and other adjustments.
Once its at operating temp, it reads the O2, and other sensors and makes adjustments based on the actual "live" readings it recieves. Then its considered to be in "closed loop".

You can't put the vehicle on a scan tool and read the computer because its not an OBDII vehicle.
(On Board Diagnostics II).

Mike