We have an '88 Grand Voyager 3.0L V6 that does the same thing, but with no "check engine" light. I'm not sure which engine your car has, but our mechanic did suspect the map sensor, too. We hooked it up to a scanner and found that the sensor was working fine. Next, we are going to try new injectors, which should solve our problem. I don't know when it's going to happen, but if we do replace them, I'll post the results. Let me know if you fix your problem.