Dodge - Intrepid :: 2004 V6 Runs Erratically - Revs Up Then Drops Back Down Again

We inherited a 2004 Dodge Intrepid SE 2.7L V6 with about 110K mileage. Basic problem: sometimes on startup the car runs terribly. It's like a cartoon car--it wheezes, bucks, snorts, revs up, drops back down again, etc., and cannot be driven. You know as soon as you turn the key whether or not it will run correctly. Sometimes when you turn the key, it starts up fine and runs fine. We've taken it to two different repair shops--our local guy and the dealership-- several times, and $1,700 later, it still happens. These are the repairs they have done: replace the map sensor, replace the camshaft position sensor, replace the crankshaft position sensor, replace the powertrain control module, replace the throttle position censor and, finally, replace the pigtail for the map sensor.

The codes usually indicate a problem with the map sensor. As a matter of fact, the last time we took it in while it was running terribly, our mechanic unplugged the map sensor while it was running and the engine ran smoothly while it was unplugged. This is what caused him to put in a new pigtail for the sensor. Anyway, after that last repair, a few uses later, the car acted up again. We've learned that if you let the car sit for a few minutes after a bad start up, it will often start up fine the next time you try. One note is that the problem has not occurred as often this summer as it did in the cooler months.