I just had the fuel pump and fuel filter on my 850 replaced a two weeks ago. The car has been running fine even thru the incredibly hot weather we've been having in the Northeast. I get home today from work and shut the car off. I come back out two hours later to go to Staples and the car starts up okay but about two blocks away from the house the engine starts to stumble and feels like it will die. This happens as I move forward from a stoplight. I have to mention as well that when I got home the weather was dry. It started raining just as I was leaving to go to Staples. What could have caused the engine hesitation? When I get to Staples and finish my business there I start up the car and now it appears to be okay. I am running out of patience with this car. I have no clue now what is causing the engine problems even with a new fuel pump and fuel filter. Could it be bad spark plug wires? A bad fuel pressure regulator? Any advice would be greatly appreciated. Thanks!