my van is goofy!! please help

my van runs fine and smooth going fast on the interstate but when i go through town it jerks and dyes at the stop sign . I was told it was something called the power valve but i dont know where this is or if this is it. I have an 89 plymouth voyager 3.0L . Please help me figure this out. Thanks Andyann

Let me know if you come up with anything mine has started doing the same thing

Let me know if you come up with anything mine has started doing the same thing
These vans are inundated with sensors, you may have a faulty throttle position sensor and when you let off the gas pedal it dies. I am having a problem with my van and after spending many $'s on what seems to be the obvious it hasn't worked. I will have to go the scanner route and check the codes.

Check the AIS (Automatic Idle Speed) Motor on your throttle body. When that fails, it'll cause the motor to die instead of holding idle. Don't know about newer vans but my 94 3 Liter had the same problem your describing. Just an idea...