I have a 2000 Impreza Rs 2.5L. Every thing is still stock except routine maintenance items. I have been having problems only during cold weather. Or when I havn't driven the car for at least one day. It started out that if I didn't let the car warm up for a few minutes it would hesitate when I excelerated through first gear but would end in 2nd gear. After a several months it now is having other problems in cold weather right when I start my car the whole care shakes excessivly. I don't have the hesitation propblem if I wait till the car warms up. Also I don't have any problems when the temprature out side is warm. I have suspected the fuel pump. I hooked up a fuel pressure guage to check the fuel pressure during idle the pressure read 28psi. If any one has any suggestions please feel free to e-mail me @ fixmuflym@yahoo.com. Or you can respond on the forum.

 

It is a rough idle like it dosn't like the cold. I pulled all the spark plugs and rechecked the gap they were slightly off. Re gapped and insltalled them. Om still having problems.

 

It hasn't done this untill just recently so I can rule out that it is just a turdy starting in the cold thanks anyways.