87 944 stumbles intermittantly
 

Car starts and runs ok, then stumbles. At idle it will actually stall, if on the road it will have a significant loss of power, as if the ignition was turned off. It usually comes back, but I am concerned that it will leave me by the side of the road, and I can't figure out what it is. It seems to only happen when warm. Does this car have a computer with memory that could be looked at? What could cause an intermittant problem? Help?!?! Intermittant problems suck.