Mitsubishi Repair: 03 eclipse with rough idle, intake air flow, mitsubishi eclipse

Question
i have an 03 mitsubishi eclipse gt it has a 3.0 v6 and an auto trans it idles good until you put it in gear and im stopped its so bad that the steering wheel vibrates if im not holding it tight it responds good when i give it gas i tuned it up changed the motor mounts and did a fuel injection cleaning to it i even took it to the dealer and the told me the computer just needed to be updated so the did that and it hasnt changed yet then they said it needed to be tuned up till i told them i just did that then told me the injectors needed cleaned i did that as well they want me to now pay them by the hour to find my problem can you help i dont have that kind of money and the car only has 85000 miles on it and most of witch are high way miles thank you

Answer
Ron,
The symptoms you described does sound like the there is a fuel supply problem.  There could be a clog in the fuel filter, bad pressure regulator, or even a weak fuel pump.  It's possible that you could have an air flow problem as well.  Restricted intake air flow or exhaust restrictions can cause your problems as well.  

You can call around to other local mechanics to see if they can find the problem.  Many may only charge you if they find and fix the problem, unlike the dealership which will charge you for any time spent.
Good luck!